FNM Corporation Ltd v Drammock International Ltd & Anor

FNM Corporation Ltd (“FNM”), which trades as FranceMed Pharma, is the proprietor of European Patent (UK) No, 0 673 403 (“the Patent”). FNM claims that the Patent has been infringed by Drammock International Ltd (“Drammock”) and LEC (L’pool) Ltd (“LEC”). The defendants do not dispute that they have infringed the Patent if it is valid, but counterclaim for revocation of the Patent and in respect of threats made by FNM. In addition FNM claims that LEC has acted in breach of contract. LEC was formerly a supplier to FNM and supplied the allegedly infringing products to Drammock. By the conclusion of the trial an apparently simple case had generated a surprising number of issues even though the defendants did not pursue two pleaded defences under sections 62(1) and 64 of the Patents Act 1977. I am concerned that the costs of this litigation will have been out of all proportion to what is at stake.

FNM is a small company owned by Mrs Nelly Kamel Malek (née Rizk) and her husband Mr Fawzi Malek, who are the directors of the company. Mrs Malek is the inventor of the patented invention. In her evidence she explained how she perceived the need for a cooling spray for various purposes, and after failing to find any satisfactory product on the market came up with the idea of a water and dimethyl ether (“DME”) aerosol. It is relevant to note that at that time she did not have the knowledge and experience of the person skilled in the art to whom the Patent is addressed, since she was an electrical engineer by training. The product she devised has been marketed by FNM since 1993 under the name Magicool. From 1999 until 2008, Magicool was manufactured for FNM by LEC.

For some years prior to 2006 Drammock had marketed a water and compressed nitrogen cooling spray aerosol under the name Cooling Mist. This product was manufactured by North West Aerosols Ltd (“NWA”). NWA was acquired by LEC in 2006, but shortly afterwards went into liquidation. In 2007 LEC commenced manufacturing Cooling Mist for Drammock, but changed the propellant from nitrogen to DME. This led to FNM bringing claims first against Drammock and subsequently against LEC. As I understand the position, LEC has stopped manufacturing, and Drammock has stopped selling, DME-based Cooling Mist. The dispute concerns 615,312 units of DME-based Cooling Mist manufactured by LEC for Drammock. It is only fair to FNM to say, however, that prior to and even during trial the defendants put forward figures for the quantities involved which were lower (indeed, to begin with, substantially lower) and inaccurate.

FNM’s expert witness was Montfort Johnsen. Mr Johnsen is a highly experienced and distinguished aerosol development technician. He obtained an MSc in Chemistry from the University of Colorado in 1949. From 1953 to 1983 he held a series of increasingly senior technical positions at Continental Filling Corp, now KIK Custom Products Inc, the world’s largest contract filler of aerosol products. Since 1983 he has acted as a consultant. Since 1987 he has been the Technical Editor of the leading aerosol trade journal Spray Technology & Marketing. He has written or co-authored five books on aerosol technology including the Aerosol Handbook. The Aerosol Handbook, the second edition of which was published in 1982, was a, if not the, standard textbook in the field, referred to at least by some as the “bible” of the industry. He has also published over 300 articles. In 1997 he became the Chairman of the world’s largest aerosol trade association, the CSMA.

Mr Johnsen was a clear and helpful witness. It is no criticism of him that he was a curious choice of expert for FNM. The reason for this that, as he made clear in his first report and confirmed in cross-examination, he was firmly of the opinion that the patented product was not a good idea. Even after reading the Patent and learning of the commercial exploitation of Magicool, he had a number of serious concerns about the safety of the product. I shall return to this point below.

A separate point is that Mr Johnsen’s perspective was that of the industry in the USA. This is relevant because, as he said in his first report and in cross-examination, DME was not popular in the USA prior to about 1993 because Du Pont, which was the only supplier in North America at that time, tried to sell it for about three to four times the price of the competitive hydrocarbon propellants. As I shall discuss below, the position was different in Europe.

The defendants’ expert was Paul Bayley. He too is a very experienced aerosol development technician. He gained a BSc in Chemistry from Nottingham University in 1969. He started work in the aerosol industry in 1973. From 1985 to 2006 he was Technical Director for Aerosols International Ltd (“AI”), now Swallowfield plc, a leading contract manufacturer of aerosol products. Since 2006 he has acted a consultant. Since 2003 he has been Chairman of the British Aerosols Manufacturers’ Association Packaging and Contents Committee. Mr Bayley was also a clear and helpful witness.

There were also a considerable number of factual witnesses. As noted above, FNM called Mrs Malek. Counsel for the defendants made no criticism of her evidence. The defendants adduced evidence from no less than 19 witnesses, many of which were to support an allegation of prior use. A number of these witnesses were not required to attend for cross-examination by FNM. I will deal with the evidence of most of the remainder below. I have not found it necessary to comment individually on the evidence given by a number of representatives of Drammock, but I should record that I consider it regrettable that some of this evidence proved to be inaccurate, albeit not on points of central importance.

The Patent was drafted by Mrs Malek herself, although I presume she obtained some professional advice. As a result, it is a slightly unorthodox document in some ways. There is no challenge to the earliest claimed priority date of 8 December 1992.

The specification begins at page 2 lines 3-13 by describing the problem to which the invention is directed:

“This invention relates to a composition and apparatus for providing a supply of water-based cool mixture and a method of providing a supply of water-based cool mixture.

Cool water or cool water-based mixture has numerous uses and applications in different aspects of life, whether drinking, cosmetic, medical or other uses. The treatment of some medical conditions such as sunstroke/heatstroke which could be fatal, requires rapid cooling of the sufferer by application of cool water. The problem is to keep the water or water-based mixture cool for a long period of time without using refrigerator or power supply. Most name portable sources of cool water mixtures such as the thermos flask or similar are temporary, most working on the principal of providing an insulated medium for the cool water-based mixture which was previously cooled or to include previously frozen ice packs.

Some of the situations which would benefit from the provision of a supply, preferably portable, of water-based cool mixture are discussed below.”

The specification goes on at page 2 lines 14-43 to discuss a variety of uses for a water-based cool mixture: cooling the body during hot weather or after exercise; treating sunstroke, heatstroke, burns and sunburn; treating fevers and hot flushes; cooling hot surfaces inside cars; and cooling enclosed spaces. At page 2 lines 45-47 the specification points out that some applications require the water-based mixture to be cooler than others.

At page 2 line 48 – page 3 line 4 the specification states:

“The above leads to the conclusion that a method is required to provide a supply of water-based cool mixture, preferably portable, delivered at a temperature below ambient in hot climates and equally important it must not reach freezing levels in order for it to be effective in addressing the above situations. Ideally the temperature of the cool water-based mixture should vary between approx. 18°C and 23°C in an ambient varying between approx. 25°C and 45° respectively. The method must also include a facility for controlling the temperature of the delivered water-based mixture in order to suit the different applications whilst accommodating the varying ambient temperatures.

A few of the above issues have been addressed in United States Patent Specification No. 5062269 ‘Disposable Body Cooler’ and in Australian Patent Specification No. 63943/90 ‘Evaporative Cooler for Human Body and Other Articles’. The present inventors are also aware of French Patent Specifications Nos. 2118398 and 2384218, and of the European Patent Specification No. 0334814 B1 and 0414920 A1. The latter describes a foam-forming aerosol preparation, which comprises Dimethyl Ether and water and is essentially flammable (since the flammable content in the preparation exceeds 45% by weight). The inventor of the present invention believes however that the present invention is an improvement over the methods and compositions described in those Specifications. The present invention therefore has as an object the amelioration of the above problems.”

After three consistory clauses, the specification states at page 3 lines 16-27:

“Throughout this specification and claims the following terms shall mean:

Pressurised: subjected to pressure above atmospheric pressure. Body: human body, including limbs, head, face, neck, etc. Cooling: reducing the temperature or elimination/absorption of heat, whether inherent heat or heat acquired as a result of external factors e.g. hot weather, without achieving freezing conditions.

Depending on the desired application, the composition of the cooling mixture may comprise from 3% to 44% by weight of the chemical compound and from 97% to 56% water or demineralised water. The invention is not however to be limited thereto. A material such as a solvent may be included to improve the miscibility/solubility of the chemical compound in the water or to modify the pressure. The amount of solvent included (if present) is preferably from approximately 1% to approximately 15% by weight of the composition. ”

The specification goes on at page 3 lines 28-52 to say that “minor amounts” of various components including fragrance, aromatic alcohol, corrosion inhibitor and antiseptic agent may be included, as may components including sun-screening composition, deodorant/antiperspirant composition and air-freshener composition.

At page 4 lines 1-6 the specification states:

“An embodiment of the composition and apparatus of the present invention will now be described, by way of example only. In a preferred embodiment of the invention a mixture of water and dimethyl ether (known commercially as DME or sometimes as methane oxybis, methyl ether or methoxy ethane) is contained within an aerosol dispenser. Dimethyl ether is fully miscible with water, forming one clear liquid phase when the percentage of dimethyl ether in water is no more than approximately 34% by weight at 20°C. The spray is applied onto the body, into the confined space or onto the hot surface and cooling thereof is achieved.”

The specification goes on at page 4 lines 7-31 to explain the mechanisms by which the cooling effect is achieved. First, DME, which has a boiling point of -24.9°C, acts as a cooling agent as well as a propellant. As it turns into gas, it absorbs heat from adjacent water molecules. Secondly, the water evaporates when it touches a hot surface or encounters a hot atmosphere and thus absorbs heat from them. At the end of this passage the specification states:

“When the cool water mixture is employed as a spray, control of the spray temperature, when falling on the object, is achieved by varying the spray distance and spray time. The spray distance is directly proportional to the temperature i.e. the longer the spray distance the higher the temperature (less cooling) and the shorter the spray distance the lower the temperature (more cooling). The spray time is inversely proportional to the temperature i.e. the longer the spray time in the lower the temperature (more cooling) and the shorter the spray time, the higher the temperature (less cooling). Ideally the spray distance should vary between 7 cm and 30 cm approximately. The ambient temperature may decide the spray distance and spray time e.g. on very hot days the spray distance may be shortened and spray time is increased to achieve more cooling. On the other hand the nature of the application may decide the spray distance.”

At page 4 lines 33-45 the specification states that a simple miscible mixture of DME and water (up to approximately 34% by weight DME) has excellent properties for cooling applications, including “Non-flammable”, “Non toxic, safe to use in confined areas with reduced ventilation” and “Produces a pleasant cooling effect on the skin, during hot weather, i.e. not too cold so as to cause a shock especially to old people and small children”.

At page 4 line 52 – page 6 line 26 the specification described six example DME and water formulations. Example 3 includes 5% by weight ethyl alcohol and 1% by weight aromatic alcohol, example 4 includes 10% by weight methylal and 1% by weight fragrance/aromatic alcohol and example 5 includes 5% by weight methylal, 4% by weight acetone and 1% by weight fragrance/aromatic alcohol.

At page 6 line 28 – page 7 line 47 the specification describes a number of applications and uses for the composition and apparatus of the invention: cooling of the body, cooling of hot confined spaces, cooling hot surfaces in a vehicle, providing cool water-based drinks and variations on the first two. The variations on cooling the body include adding a sun-screening agent, a deodorant or anti-perspirant agent and one or more of an antiseptic agent, a disinfectant and an antibiotic.

FNM relies on claims 1, 2 and 7 of the Patent as being independently valid. Broken down into integers, claim 1 is as follows:

“[1] A non-flammable composition

[2] for providing a supply of water-based cooling mixture,

[3] the temperature of which when utilised is lower than the ambient temperature and higher than the freezing point of water,

[4] which composition essentially consists of a mixture of

[a] water and

[b] a chemical compound selected from one or more of dimethyl ether, a homologue of dimethyl ether and a chemical derivative of diethyl ether.”

Claim 2 is:

“A composition according to Claim 1, wherein the chemical compound is present in an amount of from 28% to 35% by weight of the composition.”

Claim 7 is:

“Apparatus for providing a supply of water-based cooling mixture, the temperature of which when utilised is lower than the ambient temperature and higher than the freezing point of water, which apparatus comprises a pressurized dispensing container, said container containing a composition as claimed in any one of the preceding claims.”

A patent specification is addressed to those likely to have a practical interest in the subject matter of the invention, and such persons are those with practical knowledge and experience of the kind of work in which the invention is intended to be used. The addressee comes to a reading of the specification with the common general knowledge of persons skilled in the relevant art, and he (or, once and for all, she) reads it knowing that its purpose is to describe and demarcate an invention. He is unimaginative and has no inventive capacity.

In the present case there was little, if any, dispute as to the addressee of the Patent. It is addressed to an aerosol development technician i.e. a person working in a technical capacity for an organisation that manufactures and/or markets aerosol products whose task is to create or improve such products. Mr Johnsen said that he should preferably have a degree in chemistry or a similar qualification.

The law as to what constitutes common general knowledge is set out in the decisions of the Court of Appeal in General Tire & Rubber Co v Firestone Tyre & Rubber Co Ltd [1972] RPC 457 at 482-483 and Beloit Technologies Inc v Valmet Paper Machinery Inc [1997] RPC 489 at 494-495. As Laddie J explained in Raychem Corp’s Patents [1998] RPC 31 at 40:

“The common general knowledge is the technical background of the notional man in the art against which the prior art must be considered. This is not limited to material he has memorised and has at the front of his mind. In includes all that material in the field he is working in which he knows exists, which he would refer to as a matter of course if he cannot remember it and which he understands is generally regarded as sufficiently reliable to use as a foundation for further work or to help understand the pleaded prior art. This does not mean that everything on the shelf which is capable of being referred to without difficulty is common general knowledge nor does it mean that every word in a common text book is either. In the case of standard textbooks, it is likely that all or most of the main text will be common general knowledge. In many cases common general knowledge will include or be reflected in readily available trade literature which a man in the art would be expected to have at his elbow and regard as basic reliable information.”

It is convenient to make my findings as to common general knowledge in the context of a general discussion as to the relevant technical background.

An aerosol is a system of colloidal (i.e. finely divided) particles dispersed in a gas. It appears from the Oxford English Dictionary that the term was coined by Professor Frederick Donnan FRS in about 1923. By extension, the term is also, and more commonly, used to refer to a substance enclosed under pressure in a container and released as a fine spray by means of a propellant gas, and to such a container, usually in attributive form, i.e. aerosol spray, aerosol can.

The first recognisable aerosol patent was granted to Erik Rotheim, a Norwegian. His UK Letters Patent No. 278,733 (“Rotheim I”) was accepted on 1 November 1928 and claimed priority from a Norwegian application filed on 7 October 1926. Although the description and claims range more broadly, this patent is particularly directed to spraying wax onto skis. Rotheim’s propellant was DME. Rotheim was not successful in developing a commercial product, however.

Mr Bayley suggested that Rotheim I was common general knowledge. Mr Johnsen said that the skilled person would know about Rotheim’s role in the history of aerosols, but not the contents of Rotheim I. In my judgment it has not been proved that Rotheim I was common general knowledge, although some of the information it contained would have been.

In 1942 L.D. Goodhue and W.N Sullivan, who were working for the US Department of Agriculture, developed insecticidal aerosol sprays for use in the Pacific theatre of the Second World War. These sprays used chlorofluorocarbon (CFC) propellants which had been developed for use as refrigerants by Du Pont under the brand name Freon. After the War, Continental Can Corp developed a light-weight, throw-away can with a plastic valve, leading to the establishment of the aerosol industry in 1947. From late 1940s onwards a wide variety of products were made available in the form of aerosols.

CFCs had a number of advantages as propellants, including non-flammability, low toxicity, chemical stability and suitable vapour pressures. In 1974, however, M.J Molina and F.S. Rowland published an article in Nature suggesting that CFCs were responsible for depleting the ozone layer in the stratosphere. This led to CFC propellants being banned by the USA, Canada, Sweden and Norway in 1978. During the period 1980-1985 evidence supporting the Rowland-Molina theory mounted, in particular as a result of an article by the British Antarctic Survey scientists published in Nature in 1985. In September 1987 an international treaty on the protection of the ozone layer, the Montreal Protocol, was agreed. This came into force at the beginning of 1989 and provided a timetable for the phasing out of CFCs from almost all applications. After the end of 1989 CFCs ceased to be used as aerosol propellants.

Since the abandonment of CFCs, most aerosols have employed hydrocarbon gases (n-butane, iso-butane, propane and mixtures thereof such as liquefied petroleum gas or LPG) as propellants. The main alternatives to hydrocarbon propellants are DME, hydrofluorocarbons (HFCs) and gases such as compressed nitrogen and compressed carbon dioxide. The skilled person would be aware of all these propellants and their principal characteristics.

As noted above, the use of DME as an aerosol propellant has been known since Rotheim I. It appears that, prior to the late 1970s, DME was generally regarded as unattractive for use as a propellant because it was relatively expensive and there were concerns that it could form explosive peroxides with air and/or chloro-ethers with solvents such as methylene chloride. Chloro-ethers are lachrymatic and carcinogenic.

Aerofako BV, a contract aerosol filler and a subsidiary of Akzo, started serious development of DME for use as a propellant following the publication of the Rowland-Molina article in 1974. In about 1977 Union Rheinische Braunkohlen Kraftstoff AG (“URBK”), a subsidiary of Rheinisch Westfälisches Elektrikzitätswerk AG, started manufacturing highly pure aerosol-grade DME for Aerofako. By the mid-1980s URBK was manufacturing DME on a large scale, reaching 45,000 tons per annum in 1982, and Aerofako was promoting its use quite widely. In 1987 both ICI and Du Pont started marketing DME in Europe. In that year approximately 250 million aerosol cans were filled with DME in Europe. Akzo Chemie started production in about 1989.

As part of Aerofako’s efforts to promote DME, Leo Bohnen of that company demonstrated experimentally that the concerns about DME forming peroxides and chloro-ethers were unfounded. He published articles promoting the use of DME, such as a two-part article entitled “Recent European developments in DME technology” published in Aerosol Age in September and October 1988. Similar articles were published by others, such as an article by Maria Boulden of Du Pont entitled “Use of Dimethyl Ether for Reduction of VOC Content” published in Spray Technology & Marketing in May 1992.

Mr Bayley suggested that the first article by Bohnen and the article by Boulden were common general knowledge, but Mr Johnsen did not agree with this. In my judgment, it has not been proved that these articles were common general knowledge, although some of the information they contained will have been. On the other hand, I am satisfied that these articles, and other publications like them, together with the increasing commercial utilisation of DME, contributed to a change in the climate of opinion in Europe with regard to the safety of DME during the 1980s and early 1990s.

Mr Johnsen said, and I accept, that attitudes were slower to change in the USA than in Europe. This was at least partly because of the price differential referred to above, which did not apply in Europe. Nevertheless, it is noticeable that even in 1982 Mr Johnsen was writing about DME in the Aerosol Handbook in terms which did not suggest that there were any significant safety issues with regard to its use as a propellant. Thus at pages 354-355 Mr Johnsen wrote:

“…[DME] has achieved fairly large scale use in certain European countries. DME is said to account for 20% of the aerosol unit production in Belgium (1980), 17% of that in The Netherlands (1980) and 18% of the total in Japan (1979). About 22 million pounds (10,000 metric tons) were produced in Europe in 1980, accounting for about 4.6% of all European aerosols. During 1979 Japanese production amounted to about 13 million pounds (6,500 metric tons), going into about 60 million cans.”

At pages 355-356 he wrote (emphases added):

“In the presence of oxygen (or air) and ultraviolet light DME will slowly form a rather unique peroxide…. Since peroxides can be thermally or mechanically unstable, and have led to explosions in the case of diethyl ether and di-isopropyl ether, the significance of this reaction was studied in the case of DME. It has not been found to present a problem in either glass or metal containers with DME alone or in formulated products. Conjecturally, this may be because ultraviolet radiation of a sufficiently short wavelength to cause peroxidation cannot penetrate the glass or metal dispenser.

Another potential concern was the generation of bichloromethyl ether (BCME), which is considered to be a powerful carcinogenic compound. Some early data indicated 10 ppb BCME in several aerosol formulas containing both DME and chlorinated compounds. However, later tests on formulas up to four months old showed no BCMR, using special instrumentation with a threshold sensitivity of 1 ppb. ... The suggested BCMA carcinogen problem can thus be dismissed as fiction.”

At page 357 he wrote:

“The toxicological profile of DME is very good. It has a low order of acute, subacute and subchronic inhalation toxicology. Chronic studies funded by du Pont are now in progress.”

Later on the same page, he noted that, pending the completion of these studies, Du Pont would only supply DME for use in applications where the inhaled concentrations were very low and not, for example, for cosmetic or air freshener applications. This is the only reservation he expressed about the use of DME.

At page 358 of the Aerosol Handbook Mr Johnsen wrote that the strong solvent powers of DME were beneficial in the formulation of cologne and perfume aerosols. He went on:

“During 1981 a well known multi-national marketer in Europe successfully launched a line of hydroalcoholic perfume and deo-cologne sprays based on DME.

Hydroalcoholic and water-based bathroom air freshener sprays containing DME have been sold successfully in several European countries for a decade. ... Hydroalcoholic hair sprays containing up to about 15% water, along with 35% ethanol and 50% DME, have been developed ... These products are now commercial in Europe.

Underlying all these product developments is the element of cost. Both ethanol and isopropanol are taxed and are very expensive in Europe. By using a larger amount of propellant (facilitated by DME) costs can be reduced since less alcohol is required. A similar rationale can be made for using more water, which (again) is facilitated by DME formulations. …

The fiscal situation in the U.S.A. is remarkably different. Our ethanol is tax-free and sells for about 10% of the Dutch price, while DME is marketed at $0.57/lb by the sole U.S. supplier, which is around over two times the estimate current price in Europe. As a result, marketers wishing to use DME must be first prepared to pay more for their product, even if more water is used. This key factor is expected strongly to depress U.S. sales of DME except in those specific circumstances where the use of this unique propellant provides a benefit that outweighs the financial disincentive.”

At page 360 he wrote:

“In summary, dimethyl ether is a highly interesting propellant, capable of doing many things better than the conventional propellants. It is destined for a greater role in European and Japanese aerosol products. If the price decreases in the U.S.A. and Canada, its utilization in those two countries should increase remarkably in the coming years.”

In his first report, Mr Johnsen referred to material safety data sheets issued by Du Pont and BP Chemicals as showing that in 1992 suppliers of DME warned users about the risks of inhalation toxicity and frostbite with DME. So far as the latter is concerned, it is clear that this is mainly a risk attaching to the use of pure liquid DME. As to inhalation toxicity, this was not a factor that prevented the widespread use of DME as an aerosol propellant. Mr Johnsen himself said that in 1992 the known applications of DME in the aerosol industry included hair care, deodorants, insulating foams, perfumes and paints.

I conclude that in December 1992 the skilled person would be well aware that DME was a widely-used propellant at least in Europe and Japan. He would also be well aware that it was generally regarded as sufficiently safe for use as a propellant in most applications, although some care might need to be taken in applications where there was a significant risk of inhalation. Mr Bayley’s evidence, which I accept, was that by then LPG and DME were the two main options for use as the propellant in personal care products, at least in Europe.

The properties of DME are described in the Aerosol Handbook and in trade literature distributed by propellant suppliers and aerosol manufacturers such as Aerofako’s DME Aerosol Propellant Service Manual referred to below. The skilled person would be aware that DME has the following properties:

The skilled person would also appreciate that, if DME was used as the propellant for a water-based composition, the evaporation of the DME would cool the water when sprayed. (This effect was first noted in Rotheim I.) He would also appreciate that DME is a freezing point depressant i.e. it acts as an anti-freeze.

Mr Johnsen said that DME-aqueous compositions were known to be very aggressive, attacking rubber gaskets and causing corrosion in cans. So far as gaskets are concerned, I find that the skilled person would have known that care was required in selection of the gasket, but that this was not a serious problem. As Mr Johnsen wrote in the Aerosol Handbook at page 356:

“Because DME is such a strong solvent, special precautions must be used in the selection of valve gaskets and crimping specifications. …

In the case of stem gaskets, neoprene ... is good unless the methylene chloride content of the formula exceeds about 25%. Buna is possibly the best from a weight-loss standpoint, but even small additions of methylene chloride can be disastrous. The modified bunas used in Europe and to a small extent in the U.S.A. are very good and have less sensitivity to methylene chloride. Butyl rubbers are generally excellent ...”

As for corrosion, the skilled person would be aware that, if a tin can was used, a corrosion inhibitor would need to be included in the composition. If an aluminium can was used, the can would need to be coated with polyamidimid lacquer. In neither case would this present a problem.

The skilled person’s common general knowledge with regard to air fresheners is represented by the following passage from page 30 of the Aerosol Handbook:

“This rather large market is divided into two distinct product types: the air freshener and the alcohol-based disinfectant/deodorant sprays. Nearly all air fresheners consist of 0.4 to 1.0% perfume, with about 68% water, small amounts of emulsifier and inhibitors, and about 30 to 32% of hydrocarbon propellant blend… A few have actual deodorant materials, such as 3,5,5-trimethylhexanal. Still fewer are ethanol or isopropanol based, with these solvents replacing the water to give a more elegant, drier spray.”

By 1992 cooling spray aerosols were a well-known product, at least in Europe. These usually contained a mineral water such as Evian and used compressed nitrogen as the propellant. Such aerosols dispense water at approximately ambient temperature. The cooling effect is generated almost entirely by the vaporisation of the water from the surface sprayed, usually the skin. There may also be a slight cooling effect due to the expansion of the propellant gas.

Selection of aerosol cans and components such as nozzles and gaskets to produce a desired aerosol from a particular composition would have been a routine matter for the skilled person.

The task for the court when construing a patent claim is to determine what the person skilled in the art would have understood the patentee to have been using the language of the claim to mean: see Kirin Amgen Inc v Hoechst Marion Roussel Ltd [2004] UKHL 46, [2005] RPC 9 at [30]-[35]. In that case the list of principles to be found in the judgment of Jacob LJ in Technip France SA’s Patent [2004] EWCA Civ 381, [2004] RPC 46 at [41] was approved subject to one point.

There are issues as to the construction of almost every integer of claim 1, and of the corresponding integers of claim 7. Before addressing these, however, it is important to note that it is common ground that both claim 1 and claim 7 are properly to be interpreted as product claims.

The Patent does not explicitly define what constitutes a “non-flammable” composition. The passage at page 2 line 57 – page 3 line 1 stating that an aerosol preparation is “essentially flammable (since the flammable content in the preparation exceeds 45% by weight)” clearly indicates, however, that a non-flammable composition is one in which the flammable content does not exceed 45% by weight. This is consistent with British Standard 3914:1991 Specification for Non-Refillable Metal Aerosol Dispensers of 50ml to 1400ml Capacity and up to 85mm Diameter. This provides that a composition is flammable “if the contents include more than 250g or 45% by mass of flammable components”. Thus a composition is non-flammable if it contains up to 45% flammable components.

Counsel for FNM relied upon the passage at page 3 lines 23-24, which states that the “composition of the cooling mixture may comprise from 3% to 44% by weight of the chemical compound”, as indicating that the composition should not contain more than 44% of flammable components. I do not accept this. That passage is concerned with the percentage of DME (or other chemical compound). As the same paragraph of the specification makes clear, the composition may also contain another flammable component, namely a solvent such as ethanol, particularly if the DME content exceeds 34%.

Mr Johnsen pointed out that allowance had to be made for a margin of error. In my judgment, the precision to which the figure of 45% is expressed in the specification is two significant figures (i.e. the figure is not stated to be 45.0%). It follows that claim 1 embraces compositions with a total flammable content of up to 45.4%.

The defendants contend that this integer should be interpreted in a conventional manner, that is to say, in accordance with the principle that the word “for” in a patent claim means “suitable for”: seeAdhesive Dry Mounting Co Ltd v Trapp (1910) 27 RPC 341, Instituform Technical Services Ltd v Inliner UK plc [1992] RPC 83 and Coflexip SA v Stolt Comex Seaway MS Ltd [2000] EWCA Civ 242, [2000] IP&T 1332 at [23]-[27]. The effect of this interpretation is that claim 1 extends to any composition which is suitable for providing a cooling spray regardless of whether it is for use for that purpose.

FNM contends that “for” should be interpreted as meaning “for the purpose of”. The effect of this interpretation is that claim 1 is restricted to compositions which are for use for providing cooling sprays. In support of this contention counsel for FNM submitted that the law as to the effect of including the word “for” in a patent claim had been changed as a result of the decision of the Court of Appeal in Actavis UK Ltd v Merck & Co Inc [2008] EWCA Civ 444, [2008] RPC 26.

The issue of construction is tied up with an issue as to the law of novelty which it is convenient to deal with at the same time. That is whether a claim to an old product for a new use is novel where the claim is to the product rather than to the use of that product. The reason for the dispute is that the defendants rely upon prior art which discloses compositions which the defendants say fall within claim 1 but which are not disclosed as being for use for providing cooling sprays.

The relevant legislation is set out and the case law is analysed in some detail in the judgment of the Court of Appeal given by Jacob LJ in Actavis v Merck at [6]-[10] and [14]-[73]. In order to shorten my discussion, I shall assume that the reader is familiar with those passages. It is nevertheless necessary to recapitulate briefly.

In G05/83 EISAI/Second Medical Use [1985] OJ EPO 64 the Enlarged Board of Appeal of the European Patent Office held that the use of an old substance or composition for the manufacture of a medicament for a new method of treatment was novel and thus approved so-called Swiss form claims. The Enlarged Board’s reasoning in short was that the exception to Article 54(1) of the European Patent Convention contained in Article 54(5), by way of compensation for the restriction on the patentability of methods of treatment contained in Article 52(4), was not limited to the first medical use of a product but extended to second and subsequent medical uses.

In John Wyeth & Brother Ltd’s Application [1985] RPC 545 Whitford and Falconer JJ sitting en banc accepted the reasoning in EISAI and applied it to UK patents. That decision was endorsed by the Court of Appeal in Bristol-Myers Squibb Co v Baker Norton Pharmaceuticals Inc [2001] RPC 1.

In G02/88 MOBIL/Friction reducing additive [1990] EPOR 73 the Enlarged Board of Appeal held that a claim to the use of a known compound for a particular purpose was novel notwithstanding the fact that the use of that compound for a different purpose was known. As the Board noted at [2.4], the questions which had been referred to it concerned “‘use’ claims: that is, with claims defining a ‘use of compound X for a particular purpose’, or similar wording”. The Board summarised its conclusion at [10.3] as follows:

“ ... with respect to a claim to a new use of a known compound, such new use may reflect a newly discovered technical effect described in the patent. The attaining of such a technical effect should then be considered as a functional technical feature of the claim (for example, the achievement in a particular context of that technical effect). If that technical feature has not been previously made available to the public in any of the means as set out in Article 54(2) EPC, then the claimed invention is novel, even though such technical effect may have inherently taken place in the course of carrying out what has previously been made available to the public.”

It is to be noted that the Enlarged Board expressly stated at [6] that it considered that the reasoning in EISAI could not be extended to non-medical uses, but that the question with which it was concerned was a general question of interpretation of Article 54(1) and (2) EPC. It is also worth noting that the claim which was upheld by the Technical Board of Appeal following the decision of the Enlarged Board in T59/87 MOBIL/Friction reducing additive [1990] EPOR 514 was as follows:

“Use of at least 1% by weight based on the total composition of a borated glycerol ester or borated thioglycerol ester produced by borating a glycerol ester or a thioglycerol ester of the formula …. as a friction reducing additive in a lubricant composition comprising a major portion of a lubricating oil”

Although English courts have from time to time expressed unease about MOBIL, particularly when viewed from the perspective of infringement, they have refrained from holding that a MOBIL-type use claim is invalid: see in particular Merrell Dow Pharmaceuticals Inv v H.N. Norton & Co Ltd [1996] RPC 76 at 91-93 per Lord Hoffmann and Actavis v Merck at [18] and [30].

In BMS v Baker Norton Aldous LJ analysed MOBIL as follows:

“40.

That conclusion depended upon two strands of reasoning. First, that prior use was not a ground of invalidity. Thus prior use that did not make the invention available to the public could not invalidate the invention. Similar reasoning was applied by the House of Lords in Merrell Dow. Secondly, a purposive construction of the claim according to the Protocol on Interpretation was required. Thus, claims should in appropriate circumstances be interpreted as being limited to the technical effect, namely the physical activity. It followed that in the case being considered, the claim to an additive in lubricating oil for reducing friction should be interpreted as a claim to the product when used for reducing friction. Such a claim would be novel if the use had not previously been made available to the public. However it is relevant to note that similar reasoning cannot be applied in relation to a Swiss-type claim, as such a claim cannot be interpreted as relating to the product when used because that would constitute a method of treatment which is prohibited under the EPC.

41.

I do not believe that the Mobil case qualifies or amplifies the conclusion reached in Eisai. The decision in Eisai was based upon the interplay between Articles 52(4) and 54(5) of the EPC; whereas Mobil depended upon purposive construction of the claims so as to limit the claims to the product when used together with an application of Article 52(2).”

The issue in Actavis v Merck was whether EISAI extended to claims whose novelty derived from a new method of administration, and in particular a new dosage regime. The Court of Appeal held that it did, following what it concluded was established case law of the Technical Boards of Appeal, and that it was not precluded from so holding by the decision of the Court of Appeal in BMS v Baker Norton. The Court of Appeal also held that it was unlikely that the issue would be affected by the decision of the Enlarged Board of Appeal on the questions arising out of the EPC 2000 referred by the Technical Board of Appeal in T1319/04 KOS LIFE SCIENCES/Dosage regimen [2008] EPOR 27.

Counsel for FNM submitted that: (i) the Court of Appeal had made it clear in Actavis v Merck that the English courts should follow the EPO in holding that, to use the words of Jacob LJ at [18], “novelty of purpose for use can confer novelty even if the substance is old and unpatentable as such”; (ii) it was immaterial whether the claim was in the form “use of composition A for purpose B” or in the form “composition A for purpose B”; and (iii) accordingly, the word “for” in claim 1 should not be interpreted as meaning “suitable for”, but as meaning “for the purpose of”. I accept proposition (i). I do not accept propositions (ii) or (iii) for the following reasons.

First, the decision in MOBIL itself is squarely predicated on the claim being in use form. As the Enlarged Board pointed out elsewhere in the decision, at [2.1] and [5], a use claim is a claim to a physical activity, which is different from, and more circumscribed than, a product claim, which is a claim to a physical entity. As the Board put it at [5]:

“… a claim to a particular use of a compound is in effect a claim to the physical entity (the compound) only when it is being used in the course of the particular physical activity (the use) …”

Secondly, so far as I am aware, the EPO continues to allow use claims where the only novelty lies in the purpose of the use, but not to allow product claims in such circumstances: see Case Law of the Boards of Appeal of the European Patent Office (5^th ed) at paragraph 5.3.3 (pages 119-120). Counsel for FNM was unable to cite any decision either in this country or in the EPO in which a product claim had been allowed on such a basis.

Thirdly, the EPO interprets the word “for” in a product claim as meaning “suitable for”. Thus the EPO’s Guidelines for Examination (April 2009 edition) state at section C-III paragraph 4.13 (emphasis added):

“If a claim commences with such words as: ‘Apparatus for carrying out the process etc...’ this must be construed as meaning merely apparatus suitable for carrying out the process. Apparatus which otherwise possesses all of the features specified in the claims but which would be unsuitable for the stated purpose or would require modification to enable it to be so used, should normally not be considered as anticipating the claim. Similar considerations apply to a claim for a product for a particular use. For example, if a claim refers to a ‘mold for molten steel’, this implies certain limitations for the mold. Therefore, a plastic ice cube tray with a melting point much lower than that of steel would not come within the claim. Similarly, a claim to a substance or composition for a particular use should be construed as meaning a substance or composition which is in fact suitable for the stated use; a known product which prima facie is the same as the substance or composition defined in the claim, but which is in a form which would render it unsuitable for the stated use, would not deprive the claim of novelty. However, if the known product is in a form in which it is in fact suitable for the stated use, though it has never been described for that use, it would deprive the claim of novelty. An exception to this general principle of interpretation is where the claim is to a known substance or composition for use in a surgical, therapeutic or diagnostic method (see IV, 4.8).

In contrast to an apparatus or product claim, in case of a method claim commencing with such words as: ‘Method for remelting galvanic layers’ the part ‘for remelting ...’ should not be understood as meaning that the process is merely suitable for remelting galvanic layers, but rather as a functional feature concerning the remelting of galvanic layers and, hence, defining one of the method steps of the claimed method (see T 848/93, not published in OJ).”

This passage is in accordance with the case law of the Boards of Appeal: see in particular T287/86 TOBIAS/Photoelectric densitometer [1989] EPOR 214, T523/89 (unreported, 1 August 1990) and T637/92 (unreported, 21 November 1995).

Fourthly, counsel for FNM accepted during the course of argument that he was unable to point to any passage in Actavis v Merck in which the Court of Appeal had said that one should no longer construe the word “for” in a product claim as meaning “suitable for”. The nearest one gets is the contrast between Jacob LJ’s discussion of Adhesive Dry Mounting v Trapp at [15] and his discussion of MOBIL at [18]. In my judgment it is impossible to conclude that the Court of Appeal intended to imply any such thing given that: (i) Actavis v Merck was a case about second medical uses which for the reasons explained above raise somewhat different considerations; (ii) the discussion of MOBIL was obiter; and (iii) the Court of Appeal went out of its way at [45]-48] and [85]-[107] to emphasise the importance of the English courts following the jurisprudence of the EPO, and can therefore have hardly intended to put us in direct conflict with that jurisprudence.

Accordingly, I conclude that integer [2] of claim 1 is to be construed as meaning that the composition is suitable for providing a supply of water-based cooling mixture.

It follows that the first integer of claim 7 is to be construed in the same way. The slight difference in wording (“cool mixture” rather than “cooling mixture”) makes no difference.

This integer gives rise to two questions of interpretation. The first is what is meant by “the temperature of which when utilised”, and in particular the circumstances in which the temperature must be “higher than the freezing point of water”. The second is what is meant by “the ambient temperature”, and in particular whether it means the actual ambient temperature whatever that might be or some notional ambient temperature such as 20^oC.

It is convenient to deal with the second question first. In my judgment, it is reasonably clear from the specification, and in particular the passage at page 2 lines 48-53, that “the ambient temperature” means the actual ambient temperature and not some notional ambient temperature.

So far as the first question is concerned, at first blush this integer seems more appropriate to a process claim than a product claim. As noted above, however, it is common ground that claim 1 and claim 7 are both product claims. What, then, do the words “when utilised” mean?

Before attempting to answer this question, it is important to note a number of points which bear upon it. The first is that this integer qualifies the “water-based cooling [or cool] mixture” in both claim 1 and claim 7.

The second is that “utilised” covers two main possibilities, namely sprayed from an aerosol can or dispensed. The latter possibility, which applies to providing a supply of cool water-based drinks (see page 7 lines 13-16), presents less difficulty. Accordingly, attention may be concentrated on the former situation, which is also the one which matters for the purposes of the present dispute.

The third is that, apart from the words “when utilised”, the specification gives no directions as to when, where or how the temperature of the mixture is to be measured for the purpose of determining whether the temperature is between ambient and 0^oC. The defendants have not alleged that the Patent is insufficient as a result, however.

The fourth is that the specification does not describe any specific apparatus (i.e. aerosol can) for use in the invention. Nor does it contains any directions as to the characteristics of the aerosol (in particular, the particle size) which should be produced by such apparatus or as to the selection of appropriate components (in particular, the nozzle) to produce an aerosol with such characteristics. Again, however, the defendants have not alleged that the Patent is insufficient as a result.

The fifth is that, as the skilled reader would appreciate, the water in the can will almost inevitably be cooled by the action of the DME when the mixture is sprayed. (I say almost inevitably because if the percentage of DME in the mixture was low, and so only a very small proportion of DME was left in the mixture immediately after leaving the nozzle, the DME would remain dissolved in the water.) The colder the water is to begin with, the colder it will be when sprayed. Because DME is a freezing point depressant, it would be possible for the temperature of the mixture to fall below 0^oC without freezing.

The sixth is that, as the skilled reader would also appreciate, the temperature of the mixture when sprayed depends not only on the proportions of water and DME, but also on the ambient temperature and the characteristics of the nozzle and hence the aerosol that it produces. The higher the ambient temperature and the more finely divided the aerosol, the more rapidly the aerosol will absorb heat from the atmosphere at the same time as it is being cooled by the evaporation of the DME.

The seventh is that, as the skilled reader would also appreciate, the higher the ambient temperature and the further away the spray moves from the nozzle, the more the spray will pick up heat from the air through which it passes. Unless the droplets hit a surface first, at some point in their travel though the air the droplets will reach ambient temperature

FNM contends that the words “when utilised” mean that the temperature of the mixture must fall within the specified range at any point in the aerosol stream at which it is reasonably practicable to use it for cooling purposes. The defendants contend that they merely mean that the mixture is capable of falling within the specified temperature range if the mixture is used under appropriate conditions.

Counsel for FNM submitted that FNM’s construction is supported by the contrast between the passage at page 2 lines 48-53 (quoted in paragraph 11 above) and that at page 4 lines 23-32 (quoted in paragraph 15 above). The first passage says that the desired temperature of the mixture will vary depending on the ambient temperature as well as the application. The second passage says that control of the temperature of the spray when falling on the object is achieved by varying the spray distance and spray time. Counsel argued that the specification thus differentiated between the temperature of the mixture and the facility for controlling the temperature of the spray when falling on an object. I accept this, but I do not see that it helps to resolve the issue of construction.

The correct approach to resolving that issue, as always, is to try to identify the inventor’s purpose in using the words in question. In the present case, however, this is not straightforward.

There is little difficulty in ascertaining the inventor’s purpose in requiring that the temperature of the mixture when utilised be lower than the ambient temperature. This in order to achieve the desired cooling effect. (I do not think it matters that this will not always be necessary, for example if the objective is to cool a hot surface in a car, when a cooling effect could be obtained even using a mixture whose temperature was higher than ambient temperature.) That being so, the requirement that the mixture be lower than the ambient temperature cannot refer to the state of the mixture after it has reached ambient temperature. It must refer to the state of the mixture when initially sprayed. A mixture of water and DME will almost inevitably be colder than the ambient temperature when initially sprayed, however, for the reason given in paragraph 82 above.

What is rather more difficult is identifying the inventor’s purpose in requiring that the temperature of the mixture when utilised be higher than 0^oC. The specification states at page 2 lines 49-50 that “it must not reach freezing levels in order for it to be effective in addressing the above situations”, but does not explain why. The specification states at page 4 lines 43-44 that a simple miscible mixture of DME and water produces a pleasant cooling effect on the skin “i.e. not too cold so as to cause a shock especially to old people and small children”, but this does not explain why the mixture should be higher than 0^oC, since a spray whose temperature is, say, 1^oC could easily cause a shock.

It is particularly hard to understand why it is important that the temperature of the mixture should be above 0^oC when the application is cooling either a hot surface in a car or the air in a hot confined space. In those circumstances one would think that the colder the spray the better. It would not appear to matter if the temperature of the mixture dipped below 0^oC.

The only conclusion I can draw is that the inventor was concerned that the desired cooling effect would not be obtained, or there would be other problems, if the temperature of the mixture fell below freezing point. Perhaps she did not appreciate that DME was a freezing point depressant, and thought that the mixture would freeze and that that would have adverse consequences.

Even with that understanding, neither of the constructions contended for by the parties is satisfactory. The defendants’ construction appears indefinite, in that it invites the question, what are “appropriate circumstances”? FNM’s construction appears at first blush to be more certain, but suffers from essentially the same problem. What amounts to a point in the stream which is reasonably practicable for use for the purpose of cooling? When the application is cooling a confined space, the entire spray is used for the purpose of cooling until it reaches ambient temperature.

I have found it very difficult to arrive at any satisfactory construction of this integer. For some time, I was attracted by a variant of FNM’s construction, namely that the temperature of the mixture should be lower than the ambient temperature and higher than 0^oC when initially sprayed (i.e. after the formation of the aerosol, but before it begins to disperse). The fundamental problem with FNM’s construction, however, is that claim 1 is directed to a composition, but the temperature of the mixture even when initially sprayed depends not only on the characteristics of the composition, but also on the conditions of use, and in particular the ambient temperature, and on the characteristics of the apparatus, and in particular the nozzle. (This problem does not go away when one comes to claim 7, because claim 7 only partly defines the apparatus. Claim 7 says nothing, for example, about the characteristics of the nozzle.)

I have been driven to the conclusion that the only answer to this problem is to remember that integer [3] of claim 1 qualifies the words “water-based cooling mixture” in integer [2] and that integer [2] merely imposes a requirement of suitability. In other words, it is necessary to read integers [1]-[3] together as requiring a composition which is suitable for providing a cooling mixture the temperature of which will be between ambient and 0^oC when initially sprayed under appropriate conditions and in particular from appropriate apparatus. This is a construction close to that contended for by the defendants.

Counsel for FNM submitted that interpreting integer [3] in the manner contended for by the defendants amounted to treating that integer as struck out contrary to the principle articulated by Hoffmann LJ (as he then was) in Société Technique de Pulversation STEP v Emson Europe Ltd [1993] RPC 513 at 522. I do not consider that my construction offends that principle. I have not treated integer [3] as if it were struck out. On the contrary, I have done my best to interpret it. It is true to say that my construction means that it has little limiting effect on the claim, but that is not the same thing.

The corresponding words in claim 7 should be interpreted in the same way, i.e. as requiring an apparatus containing a composition which is suitable for providing a cooling mixture the temperature of which will be between ambient and 0^oC when initially sprayed under appropriate conditions and in particular from apparatus comprising appropriate components.

It is common ground that the expression “consists essentially of” permits the presence of other components. It is clear from the specification, and in particular the examples, that significant quantities of other components, and certainly up to 11% by weight, may be incorporated.

The defendants pleaded no less than 19 prior publications. In the end, however, they relied on just six of these. The first three are alleged to anticipate clams 1, 2 and 7. All six are relied on starting points for obviousness attacks.

United States Patent No. 3,207,386 (“Presant”) was published on 21 September 1965. Presant’s invention is summarised at column 1 lines 65- column 2 line 9 as follows:

“Our invention provides self-propelled liquid dispensing utilising a comparatively inexpensive, flammable propellant, i.e. dimethyl ether, to dispense an active ingredient containing liquid aqueous phase in the form of a non-foaming, non-flammable spray containing relatively large amounts of water with complete extrusion of the liquid aqueous phase. Moreover, in accordance with our invention a finely atomized spray approaching the properties of a conventional anhydrous spray can be obtained.

As embodied in a dispensing device, our invention comprises a self-propelled liquid dispenser including a container containing under pressure a fluid system comprising a propellant vapour phase and an essentially continuous liquid aqueous phase containing an active ingredient solute, water and a propellant comprising dimethyl ether, and a valve member associated with the top of the container for dispensing the contents of the container in the form of a spray.”

Presant contains a number of examples illustrating different uses for compositions based on DME. The defendants focussed on Example IV. This discloses a system useful as a non-alcoholic spray bandage for burns consisting of 67.0% by weight water, 30.0% by weight DME and 3.0% by weight polyvinylpyrrolidone/vinyl acetate. After describing the valve employed with this system, Presant states:

“The liquid aqueous phase of this system was continuous and a spray of this product was characterized by a finely atomized spray approaching conventional anhydrous type products. The product sprayed down evenly and was extruded completely as a non-flammable spray.”

United States Patent No. 4,466,838 (“Schwarzkopf II”) was published on 21 August 1984. Schwarzkopf II discloses carrier mixtures for aerosol preparations. Schwarzkopf II states at column 1 line 48 – column 2 line 14 that it is an object of the invention to provide a carrier mixture which has a number of characteristics, including that it “does not contain more than 45 per cent by weight of inflammable constituents”. It states at column 2 lines 33-38 that:

“The carrier mixtures, according to the invention, of the aerosol preparations can be formulated with cosmetic, hygienically or medically active constituents (active ingredients) and yield preparations for diverse purposes, for example as a cosmetic spray, room spray or medicinal spray, preferably deodorant sprays.”

Table I discloses examples of carrier mixtures of the invention. Example I contains 54.0% by weight water, 35.0% by weight DME, 10% by weight ethanol and 1.0% by weight of compressed carbon dioxide.

Examples 1 to 9 consist of aerosol preparations prepared from the carrier mixtures of the invention. Examples 3 and 5 are antiperspirant spray preparations containing 96.7% by weight of carrier mixture I, 3% by weight of a perspiration inhibitor (for example, aluminium hydroxychloride) and 0.3% by weight of perfume oil. Table II discloses that Examples 3 and 5 contain 56.19% by weight of non-inflammable constituents.

United States Patent No. 4,712,032 (“Westfall”) was published on 29 December 1987. It discloses an aerosol spray composition containing disinfectant for mastitis prevention in dairy cattle and other animals. The specification records at column 1 lines 5-52 that one of the advantages of the aerosol spray composition produces a desirable chilling effect on the cow’s teat.

At column 4 lines 55-63 Westfall discloses a composition contained 44.767% by weight of water, 35.0% by weight of DME, 10.0% by weight of ethyl alcohol, 9.83% by weight of glycerine, 0.4% of chlorhexidine acetate (a disinfectant) and 0.003% by weight of blue dye.

At column 5 lines 10-23 Westfall states:

“The method of the present invention has been found to be particularly effective when a temperature in the range of from about 25° to 35° F is rapidly attained on the exterior surface and orifice end of the teat 12 of the cow. Such a temperature should be obtained for at least approximately one second duration in order to achieve proper contraction of the sphincter 26. In general, the reduction of temperature on the teat surface adjacent the teat orifice 24 should be a value as cold as practical without creating tissue damage, preferably close to or slightly below the freezing temperature of water. The composition of the present invention has been found to provide such temperatures when applied as an aerosol spray 14 described herein.”

The DME Aerosol Propellant Service Manual is a technical manual distributed by Aerofako. The version relied on by the defendants is the second edition dated September 1986. The defendants rely in particular one of the “recommended basic aqueous compositions” set out in a table on page 23, namely that for a “wet” air freshener. This composition contains 70% by weight water and 30% by weight DME.

United States Patent No. 4,813,238 (“Tan”) was published on 21 May 1989. It discloses an atomised spray for cooling the passenger compartment of an automobile. The preferred embodiment is a mixture of about 20% by weight of alcohol and 79% by weight of water together with a balance of fragrance and a non-toxic aromatic alcohol. Tan suggests at column 2 lines 37-38 that “a liquid propellant such as carbon dioxide or nitrogen is employed to eject the solution” from an aerosol can.

United States Patent No. 4,983,314 (“Yudin”) was published on 8 January 1991. It too discloses a composition for lowering the temperature in a confined space such as the interior of a closed vehicle. Yudin states at column 1 lines 34-40 that the composition consists “essentially of: about 5-15% by volume of methyl alcohol; about 20% by volume of a propellant; about 0.5% by weight of sodium benzoate; about 0.2% by volume of fragrance; about 0.2% by volume of morpholine; and about 64.1 to 74.1% of deionized water”. At column 2 lines 19-22 it states that “any safe propellant conventional in the industry as would easily be suggested to one skilled in the art can be employed”.

The defendants allege that LEC made and sold at least two products falling within claims 1, 2 and 7 of the Patent in the mid-late 1980s. FNM does not dispute that LEC did make and sell products of the kind alleged, but vigorously disputes that the products had the compositions claimed by the defendants. This dispute took up a considerable amount of time at trial.

In considering the evidence I have borne firmly in mind that the burden of proof is on the defendants. On the other hand, an issue should not be determined purely on the basis that the burden of proof has not been discharged unless the court cannot reasonably make a finding in relation to that issue despite having striven to do so: see Stephens v Cannon [2005] EWCA Civ 222, [2005] CPRep 31 at [46].

Mr Clare’s evidence. It is convenient to begin with the evidence of Lawrence Clare, LEC’s managing director. Mr Clare owns 75% of the shares in LEC and his wife Eileen owns the remaining 25%. Mr Clare’s evidence may be summarised as follows.

LEC was established in 1967 as a wholesale hairdressing supplier to hairdressing salons. In about 1968 or 1969 LEC employed Richard Singleton, a retired chemist. In 1972 LEC started making hairspray aerosol cans. Since then LEC has become a successful aerosol manufacturer, particularly of hairspray sold under the brand name Insette. In the 1970s LEC developed a hair mousse aerosol which was sold under the same brand name. At that time LEC was using CFCs as propellants.

Mr Clare recollected that in about 1982 or 1983 Mr Singleton was replaced by Tom Simcock, who had previously been employed by ICI for 20 years in its aerosol research laboratory. At around the same time, LEC started to experience demand for ozone-friendly products. Initially LEC tried butane, but found that this caused a problem with the hairspray because LEC was unable to find a resin which was compatible with butane. Mr Simcock therefore suggested that LEC should try DME. DME had the advantage compared to butane that it was miscible with water, which means that LEC could continue with its Insette hairspray formulation virtually unaltered. This compensated for the fact that DME was more expensive than butane. LEC started purchasing DME in bulk from Aerofako through a supplier called Electrochem in about 1985.

In 1985 LEC sold its Insette products at a hairdressing exhibition at Earl’s Court in London. Mr Clare noticed that many of the women attending the exhibition suffered from aching feet since the exhibition hall had a concrete floor, it was crowded and hot and there was very little seating.

In 1986 LEC returned to the Earl’s Court exhibition with a promotion offering a can of Insette hair mousse for 99p together with a can of foot-cooling spray for a nominal 1p. According to Mr Clare, the foot-cooling spray was roughly one-third DME, two-thirds water and a touch of fragrance. LEC continued to use this spray as a marketing tool afterwards as it was cheap and easily produced. LEC sold it to hairdressing salons and chemists, but it was not very successful. LEC also sold the same product for use as a sanitising spray for bowling shoes in bowling alleys, particularly in the Liverpool area, and as a sanitising spray for sunbeds. In addition, LEC occasionally filled “tag ends” of cans with similar compositions which were supplied as “make weight” products.

Mr Clare said that essentially the same formulation was used for all these products. It was put to him, and he accepted, that it was probable that the formulation contained some alcohol. He made it clear, however, that he did not have precise knowledge of the formulations used since that the responsibility of LEC’s chemist.

In April 1987 Mr Simcock was replaced by Mike O’Garra, who had previous experience of working with DME. Mr O’Garra subsequently died in June 1996.

In 1988 LEC changed its supplier to DuPont and soon became one of its biggest customers for DME.

In 1989 LEC moved to larger premises. After the move, it stopped making many of its smaller products, including the foot cooling spray. It did continue making the bowling alley shoe sanitiser spray.

By 1990-1991 LEC was using so much DME that buying it in half tonne drums was no longer viable, and so LEC had an 18 tonne tank installed at its premises.

In October 1991 LEC suffered a major fire at its premises, as result of which many documentary records from prior to that date were destroyed. LEC was, however, able to disclose a copy of the DME Aerosol Propellant Service Manual dated September 1987. This was found by Mr Daly (as to whom, see below) in a drawer.

Mr Clare struck me as a truthful witness. He had understandable difficulty in recalling precisely the events of more than 20 years. Moreover, it is not surprising in view of his age and recent heath problems that at times he became a little confused during the course of cross-examination. The essential points of his evidence, however, were coherent and plausible. Furthermore, many parts of it are corroborated by other witnesses and such documents as have survived. That said, he was not in a position to give the most reliable evidence about the precise formulations of the products in question.

Unchallenged evidence. It is convenient next to consider the evidence of a number of witnesses called by the defendants whose evidence was not challenged.

Anthony Bullen was employed by LEC as its director of printing from September 1978 to March 2002. He recalled printing cans for Insette Cooling Foot Spray in the later 1980s. He also printed cans for Insette Shoe Sanitizer for bowling alleys.

Anne Duffy was employed by LEC as a sales representative from February 1984 to June 1992. During that time she sold a foot spray, a sanitising spray for sunbeds and a refreshing spray for bowling alley shoes. The products had almost identical formulations.

Deborah Dwyer was employed by LEC as a sales ledger assistant in June 1990. She recalled processing orders and invoices for Insette Sanitiser Spray to Hollywood Bowl in Bolton, Blackburn and Liverpool.

Adele Fishwick was employed by LEC as a graphic artist by LEC from June 1985 to June 1993. During that time she originated artwork for products called Cooling Foot Spray and Shoe Sanitizer.

Frank Forshaw owns or is employed by a chemists shop in Liverpool. He recalled purchasing an aerosol foot spray from LEC in the late 1980s and early 1990s.

Norman Lonorgan was employed by LEC as a salesman from 1980 to about 2000. He corroborated Mr Clare’s account of the events at the 1985 and 1986 Earl’s Court hairdressing shows. He also said that LEC was unsuccessful in selling the foot cooling spray thereafter, but did sell the product as a sanitizer spray for bowling alleys.

Susan McLaughlin was employed by LEC as a sales representative from 1987 to about 1989. Prior to that she owned a salon. She said she attended the Earl’s Court hairdressing trade show in 1985 and 1986 as a guest of LEC and that LEC used the promotional tool of a foot cooling spray as a “freebie”.

Colin Rawles worked for Electrochem, which was taken over by Linde Gases in 1993, as a technical salesman and then sales manager from 1985 until 1997. He recollected that he began selling DME to LEC between 1986 and 1988.

Tom Simcock’s evidence was that he started working for LEC as its chemist three days a week in 1981. From mid-1986 when Mr O’Garra started to work for LEC, he worked for LEC as a consultant one day a week until about 1989. Prior to taking up employment with LEC, he worked for ICI in its aerosol laboratory on technical service. Importantly, Mr Simcock said that around the time he took up his employment with LEC, LEC started production of aerosols with water and DME, and sometimes with ethanol. He said that DME was particularly useful in some formulations because of its miscibility with water. His recollection was that the formulations used by LEC were available in the technical literature.

Richard Stockman worked from Aerosol Research and Development (“ARD”), which was taken over by Lindal Valves in 1997, from 1966 to 2002. He was appointed Sales Director of ARD in 1984. He recalled that ARD started supplying valves to LEC in 1976. At some point in the 1980s, which could have been as early as 1982 or 1983, LEC changed its order to lacquered tinplate valves to accommodate water/DME products.

Mr Daly’s evidence. Stephen Daly has been employed by LEC since 1971. Until the mid 1980s he was a salesman. He is now a director of the company with responsibility for its finances. His evidence may be summarised as follows.

He recalled that in about 1984/1985 LEC purchased DME from Electrochem, initially for laboratory testing purposes. In 1986 LEC introduced a foot cooling spray at the National Hairdresser’s Exhibition at Earl’s Court and also a sanitizer shoe spray. These products were sold to hairdressers, chemists and bowling alleys. Both products used contained one-third DME and two-thirds DME. He knew this because he used to have lunch regularly with Mr O’Garra, who discussed the benefits of using DME with him. A big selling point of DME was its water solubility. Other DME and water products sold at the time included a sunbed cleaner.

Mr Daly accepted that it was possible that the foot cooling spray and sanitizer shoe spray had a small amount of perfume and alcohol in them, but he did not know. He was certain that he remembered Mr O’Garra saying one-third DME and two-thirds DME.

Mr Daly struck me as a truthful witness. He was clear and firm on the matters summarised above. His evidence is corroborated by other witnesses and documents. That said, like Mr Clare, he was not in a position to give the most reliable evidence about the precise formulations of the products in question.

Mr Birch’s evidence. Phil Birch worked for LEC as a salesman and then sales manager from February 1978 to September 1986 and from February 1994. Most of his evidence was directed to other issues, but he said that the product LEC sold to Drammock was in effect the same as the make weight or tag end products LEC had made for twenty years. This evidence is not particularly significant by comparison with of Mr Clare and Mr Daly.

Mrs Malek’s evidence. Mrs Malek first contacted LEC in about February 1994 when searching for a second aerosol manufacturer to make Magicool for FNM in addition to Greenhill Chemicals, FNM’s existing manufacturer. Peter Bleasby of Du Pont (as to whom, see below) gave Mrs Malek Mr O’Garra’s name. She sent him a non-disclosure agreement dated 2 March 1994, which Mr O’Garra signed on behalf of LEC. She also sent him the 1993 Magicool data sheets and asked him for a quotation. She did not hear from for a while, and so she telephoned him at the end of March 1994. He expressed concern about the safety of Magicool. According to Mrs Malek, Mr O’Garra commented that Magicool had a high water content and a very low ethanol content which was not sufficient to dissolve the perfume. He suggested a minimum ethanol content of about 25%. When Mrs Malek mentioned that increasingly the ethanol content would make the spray flammable, Mr O’Garra said that this was not a problem as all the DME formulations that he had worked on were flammable.

While I accept that Mrs Malek honestly believes her account of her conversation with Mr O’Garra, I do not find it plausible. This is for three main reasons. First, Mr O’Garra would surely have known that the perfume could be dissolved by a small quantity of an alcohol. If he was concerned about this aspect of the composition, he would be more likely to have suggested changing the identity of the alcohol e.g. to an aromatic alcohol. Secondly, if Mr O’Garra was concerned about the safety of Magicool, he would surely not have suggested making it flammable. Thirdly, I think it is unlikely that Mr O’Garra was not aware of the existence of non-flammable DME and water compositions, such as the “wet” air freshener carrier composition disclosed by the DME Aerosol Propellant Service Manual which LEC had in its possession at that time. For these reasons I consider that Mrs Malek must have misremembered the conversation, which took place some 15 years ago.

Mrs Malek also gave evidence that, when she approached LEC for the second time in 1997 (as to which, see below), LEC had difficulty in producing acceptable samples, and in particular a problem with the corrosion inhibitor. She suggested that this demonstrated that LEC had no previous experience with corrosive water and DME mixtures.

Mr Savage’s evidence. Edward Savage was employed by LEC as its chemist from September 1996 to May 2003. He replaced Mr O’Garra who had died about three months before he took up his position with LEC. His evidence turned out to be of crucial importance with regard to the formulations of the products in question.

Before turning to that, I shall deal with Mr Savage’s response to Mrs Malek’s evidence summarised in paragraph 141 above. Mr Savage’s evidence was that he had to undertake a short period of routine development work because FNM’s 1993 Data Sheets (as to which, see below) did not specify the grade or supplier of the chemicals or how they should be mixed. He pointed out that he had only started work in September 1996, and accepted that he personally had done little if any work on water and DME mixtures between then and May 1997, but said that it did not follow that LEC had no prior experience with such mixtures. I agree with Mr Savage.

In his first witness statement, Mr Savage related that, on arriving at LEC, he found that LEC needed a new computerised control and records system for the areas in which he worked. Previously the technical records had not been computerised. He therefore set out computerising the records. He began with LEC’s current products. After that, he computerised the records of earlier products. In about December 1996 he had found some cans of a shoe sanitizer spray for bowling alleys. Mr Daly told him that this product had been manufactured and discontinued some years previously. Looking through the files, he found the formulation for this product. He described this formulation in paragraph 8 as follows:

“A water and DME mixture; an active ingredient Vantocil 1B (sourced from ICI) which is a disinfectant; a perfume. There was some ethanol. A corrosion inhibitor was present.”

Mr Savage added in paragraph 9:

“At the same time as I found the sanitizer formulation, as part of this computerisation of the documentary records of some of the former products of LEC, I found two other formulations of interest. One was a foot cooling spray. The other was a sunbed cleaning or sanitizer spray. Both of these were water and DME mixtures of approximately 2 parts water and 1 part DME.”

At that time, LEC was unable to find any of the computer records referred to by Mr Savage.

Mr Savage was cross-examined on the fourth day of the trial, 3 April 2009. Mr Savage explained at an early point that he was recovering from an ear infection and was having difficulty hearing. It did not appear, however, that this difficulty was insuperable.

Mr Savage explained that the only relevant formulation he had put on LEC’s computer was the bowling shoe spray formulation, he has not recorded the other two formulations mentioned in his paragraph 9 of his first statement.

So far as the bowling shoe spray formulation is concerned, it emerged during the course of his cross-examination that Mr Savage had annotated paragraph 8 on a copy of his first witness statement which he had brought with him. The annotations indicated that the formulation consisted of 65.93% water, 30% DME, 3.5% ethanol, 0.21% Vantocil 1B, 0.13% sodium benzoate (corrosion inhibitor), 0.02% sodium nitrite (anti-oxidant) and 0.23% perfume. These figures are not quite correct, since they add up to more than 100, but I do not think that matters particularly.

Mr Savage went on to say that he had obtained these figures from a copy of the computer record which he had on a floppy disk at home which he was prepared to disclose.

When asked about paragraph 9 of his first statement, Mr Savage said this:

“Q. I now understand what you are saying. Moving on to paragraph 9, where you talk about two other formulations of interest. One was a foot cooling spray. The other was a sunbed cleaning or sanitizer spray. ‘Both of these were water and DME mixtures of approximately 2 parts water and 1 part DME.’ That you remember, do you?

A. Yes. One I noticed was a shadow of that particular one.

Q. It was a shadow of that. So it was very similar to this?

A. Yes. And the other one was a free-standing one. But the details, apart from what I have put down there, I do not know. I cannot remember.

Q. Why did you not put these two other products on the computer?

A. In actual fact, I looked at the first one and I thought I could actually change that to make that a mixture of butane and DME in the future some time. That was all. It was an experiment for me.

Q. So it was for your benefit that you wrote this down rather than the company's benefit?

A. Absolutely.

Q. As far as those products are concerned, you do not remember any more about them than one was quite similar to the first one and the other one was different?

A. Yes; it was more ethanol.

Q. It was more ethanol. That, one would suppose, might be the sunbed cleaner?

A. The sunbed cleaner was the shadow of the original shoe spray.

Q. So the foot cooling spray had a lot of ethanol in it, you are saying?

A. There was more ethanol in it; yes.

Q. Do you know how much?

A.

I do not remember. It may be double. I don't know.”

Mr Savage went on to say that he had found the formulations in the laboratory files. They had been written by Mr O’Garra, whose handwriting Mr Savage had became familiar with, on pieces of paper.

At the conclusion of Mr Savage’s evidence it was agreed that the defendants would obtain and disclose the relevant file from the floppy disk to which Mr Savage had referred. Subject to that, the evidence was concluded and the trial was adjourned to 23 April 2009 for closing submissions.

At the time Mr Savage struck me as a truthful witness whose evidence was broadly consistent with that of the other witnesses described above.

Subsequently the defendants served a third witness statement of Mr Savage. In this statement Mr Savage begins by saying that at the time he gave evidence he was unwell from an infection in both ears, tired from waiting around to give evidence and confused. (He does not mention his age, but he would be entitled to rely on that as well.) He goes on to say that, when he returned home, he was unable to find the floppy disk. He has concluded, for reasons he explains, that it was probably thrown away by his wife in January 2009, which was before he was asked to give evidence in this case. He says that he made the annotations on the copy of his first witness statement in his hotel room on 3 April 2009. These figures were a hypothetical formulation which he had devised for his own personal satisfaction, they were not intended for publication. It was not a formulation recorded on the floppy disk or anywhere else.

Mr Savage goes on to say that he has since visited LEC. The computer which he had caused LEC to acquire in 1996 was thrown away in 2003, but some of the files were transferred to a replacement computer. He has been shown a print-out of a file from the replacement computer. This is his “projects” file in which he had stored a couple of dozen formulations. One product for which there are formulations in the projects file is described as “Multi-Purpose Sanitizer Spray”. One of these formulations is marked “Original recipe” and contains DME. Mr Savage says that he believes that this is the formulation for the bowling shoe spray he extracted from LEC’s old laboratory files even though it is apparently dated February 2000.

The formulation in question consists of 40% DME and 60% of a mixture which is 29.83% water, 69.33% IMS (industrial methylated spirit i.e. ethanol with some methanol added), 0.3% Vantocil 1B, 0.18% sodium benzoate, 0.02% sodium nitrite and 0.33% perfume.

Mr Savage goes to repeat that he does not have a record of the other two formulations of sprays referred to in paragraph 9 of his first statement. He describes these in more detail as follows:

“The foot cooling spray formulation I found in the LEC old files when I found the sanitizer spray was a composition with a product to ‘gas’ ratio (weight to weight) of 68:34 or 70:30. DME was the propellant; with 5% (weight by weight) ethanol at most; and no Vantocil 1B (no disinfectant). The bulk of the weight was made up of water.

The sun bed cleaning or sunbed sanitizer spray formulation I found in the LEC old files when I found the sanitizer spray was a composition with a product to ‘gas’ ratio (weight to weight) of 68:34 or 70:30. DME was the propellant; with less than 10% (weight by weight) ethanol (for flammability reasons), and with Vantocil 1B (disinfectant). The bulk of the weight was made up of water.”

The defendants also served a third witness statement of Mr Render of LEC (as to whom, see below) explaining that, after learning of Mr Savage’s first statement in early March 2009, he had searched LEC’s computer for a record of the sanitizer spray Mr Savage had referred to. He had found the “Original recipe”, but had not caused LEC to disclose it to FNM since he judged it irrelevant as it was dated 2000 and would have been extremely flammable, and thus did not appear to match Mr Savage’s description.

I have to say that it is regrettable that the file was not disclosed prior to trial. It appears that Mr Render did not think to discuss the file with Mr Savage before making a decision as to its relevance or otherwise. To my mind, that was an error of judgment, but I did not consider that it was a culpable one.

When the trial resumed on 23 April 2009, the parties agreed that, in the interests of avoiding the costs that would be wasted if the trial were to be adjourned and Mr Savage recalled, Mr Savage’s third statement would be admitted without cross-examination and FNM would be at liberty to submit that Mr Savage’s evidence was false without putting that allegation to him in cross-examination as would normally be required.

Although I was prepared to acquiesce in this arrangement, I have to say that I do not regard it as very satisfactory. It is not fair to the witness and it makes it more difficult for the court to be sure where the truth lies.

As envisaged by this agreement, counsel for FNM submitted that Mr Savage’s evidence was false. Indeed, he went so far as to submit that the evidence I have quoted in paragraph 159 above was “a total and obvious concoction”. I do not accept this. Mr Savage is a retired professional chemist. He has had no connection with LEC for over 6 years. No cogent reason has been advanced as to why he should engage in an outright lie. Moreover, if he were prepared to engage in such a concoction, why would he voluntarily reveal the true position regarding the bowling shoe sanitizer spray?

It is fair to say that, given the apparent contradiction between some of the things that he said during cross-examination and his subsequent evidence, Mr Savage’s evidence has to be treated with some caution. Nevertheless, I am prepared to accept the explanation given in his third statement that he was unwell, tired and confused at the time of his cross-examination. Furthermore, I am prepared to accept that in the passage of cross-examination I have quoted in paragraph 152 above Mr Savage was confused between the foot cooling spray and the sunbed sanitizer spray and got them the wrong way round.

Moreover, when viewed against the background of the other evidence set out above, I consider that the evidence about those two formulations set out in Mr Savage’s third statement is plausible. In particular, it is plausible that the two formulations should not have contained much ethanol. The foot-cooling spray did not need to be a “dry” spray and so did not need to contain much ethanol, which would be an unnecessary expense. In the case of the sunbed sanitizer spray, one can appreciate that flammability would also be a concern. By contrast, it is logical that the bowling shoe spray should have been a “dry” spray containing a substantial proportion of ethanol, since one would not want the shoes to get wet. Mr Savage’s evidence in his third statement is broadly consistent with his evidence in his first statement and under cross-examination. It is also broadly consistent with the evidence of the other witnesses, as it is not surprising that witnesses like Mr Clare and Mr Daly should not have known or remembered that the bowling shoe spray contained a substantial proportion, and the other formulations small proportions, of ethanol. Mr Savage’s evidence is certainly not an obvious concoction.

Conclusion. FNM does not dispute that LEC made and sold a foot-cooling spray and a sunbed sanitizer spray when it says it did. Nor does FNM seriously dispute, if at all, that they contained DME as the propellant. FNM contends that, like the bowling shoe spray, the other two products contained a substantial proportion of ethanol and therefore were flammable. I do not agree. Weighing all the evidence together, I find that in 1986, and for some time thereafter, LEC did make and sell a foot cooling-spray and a sunbed sanitizer spray having the formulations described by Mr Savage in his third statement.

As was explained in Synthon BV v SmithKline Beecham plc [2005] UKHL 59, [2006] RPC 10, in order for an item of prior art to deprive a patent claim of novelty, two requirements must be satisfied. First, the prior art must disclose subject matter which, if performed, would necessarily infringe that claim. As it was put by the Court of Appeal in General Tire and Rubber Co v Firestone Tyre and Rubber Co Ltd [1972] RPC 457 at 486, “[t]he prior inventor must be shown to have planted his flag at the precise destination before the patentee”. Secondly, the prior art must disclose that subject matter sufficiently to enable the skilled addressee to perform it. In the present case the dispute is over the first requirement rather than the second.

It is clear that Example IV of Presant discloses a composition which satisfies the requirements of integers [1] and [4] of claim 1 and the additional requirement of claim 2.

So far as integer [2] of claim 1 is concerned, the composition disclosed in Example IV satisfies this requirement as I have construed it. The composition is suitable for providing a supply of water-based cooling mixture. The fact that it incorporates a polymer for producing a bandage is immaterial. Indeed, this is an application quite similar to some of those disclosed in the Patent.

As to integer [3], in my judgment the composition disclosed in Example IV satisfies this requirement as I have construed it since the composition is suitable for providing a cooling mixture whose temperature will be between ambient and 0^oC when initially sprayed under appropriate conditions. The composition is very similar to those disclosed in the Patent, and there is no evidence that the inclusion of the polymer would necessarily cause the temperature of the mixture to fall below 0^oC.

It follows that Example IV of Presant anticipates claim 1 and 2 of the Patent.

Read in context, Example IV also discloses an apparatus which satisfies the additional requirements of claim 7. Mr Johnsen observed that Example IV did not disclose a gasket for the valve specified, and said that no suitable gasket was known in 1962; but I did not understand there to be any dispute that the disclosure would have been enabling when read in December 1992 because suitable gaskets were then available as discussed above.

Examples 3 and 5 of Schwarzkopf II clearly satisfy the requirements of integer [1] of claim 1 since their flammable content is below 45%. They also clearly satisfy the requirements of integer [4] and the additional requirement of claim 2, since the DME content is 33.8% (96.7% x 35%).

These examples satisfy the requirements of integer [2] as I have construed it, since they are suitable for use as cooling sprays. The application is one that is expressly contemplated by the Patent.

As to integer [3], in my judgment the composition disclosed in Examples 3 and 5 satisfies this requirement as I have construed it since the composition is also suitable for providing a cooling mixture whose temperature will be between ambient and 0^oC when initially sprayed under appropriate conditions. The composition is quite similar to those disclosed in the Patent, and there is no evidence that the inclusion of the perspiration inhibitor would necessarily cause the temperature of the mixture to fall below 0^oC.

It follows that Examples 3 and 5 anticipate claims 1 and 2 of the Patent.

Schwarzkopf II also discloses an apparatus for use with these compositions which has the additional requirements of claim 7. It follows that Schwarzkopf II also anticipates claim 7.

The flammable content of the composition disclosed in Westfall is 45.0%. Accordingly the composition is non-flammable as I have construed that expression. The composition clearly satisfies the requirements of integer [4], and it also satisfies the additional requirements of claim 2 since the DME content is 35.0%.

So far integer [2] is concerned, the composition is not merely suitable for use for providing a cooling mixture, it is actually disclosed as being for use as a cooling mixture.

As to integer [3], the composition satisfies this requirement as I have construed it since the composition is also suitable for providing a cooling mixture whose temperature will be between ambient and 0^oC when initially sprayed under appropriate conditions. Westfall says that the composition provides temperatures close to or below the freezing temperatures of water when employed in the manner proposed, but it does not follow that the mixture will necessarily fall below 0^oC when utilised. On the contrary, it is probable that the temperature of the mixture would be well above 0^oC when initially sprayed if it was sprayed into a hot confined space.

Westfall also discloses an apparatus for use with the composition having the additional requirements of claim 7.

It follows that Westfall anticipates claims 1, 2 and 7 of the Patent.

The foot-cooling spray and the sunbed sanitizer spray both anticipate claims 1, 2 and 7 of the Patent.

A patent will be invalid for lack of inventive step if the invention claimed in it was obvious to a person skilled in the art having regard to the state of the art at the priority date. The familiar structured approach to the assessment of allegations of obviousness first articulated by the Court of Appeal in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59 has recently been re-stated by Jacob LJ in Pozzoli v BDMO SA [2007] EWCA Civ 588, [2007] FSR 37 at [23] as follows:

“(1)

(a) Identify the notional ‘person skilled in the art’;

(b)

Identify the relevant common general knowledge of that person;

(2)

Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;

(3)

Identify what, if any, differences exist between the matter cited as forming part of the ‘state of the art’ and the inventive concept of the claim or the claim as construed;

(4)

Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?”

In both H. Lundbeck A/S v Generics (UK) Ltd [2008] EWCA Civ 311, [2008] RPC 19 at [24] and Conor Medsystems Inc v Angiotech Pharmaceuticals Inc [2008] UKHL 49, [2008] RPC 28 at [42] Lord Hoffmann approved without qualification the following statement of principle by Kitchin J at first instance in the former case:

"The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success."

What matters is whether or not the invention was technically obvious, not whether it was commercially obvious: see Hallen Co v Brabantia (UK) Ltd [1991] RPC 195 at 213. This does not necessarily mean that commercial considerations are irrelevant. The mindset of the skilled person may be conditioned by commercial considerations only to consider certain types of technical solutions, as in Dyson Appliances Ltd v Hoover Ltd [2001] EWCA Civ 1440, [2002] RPC 22.

In considering whether an invention is obvious, it may sometimes be important to consider whether the addressee would have a technical prejudice against taking a particular step. I considered this aspect of the law of obviousness in my judgment in Dyson Technology Ltd v Samsung Gwangju Electronics Co Ltd [2009] EWHC 55 (Pat) at [153]-[157]. I concluded that, where the patentee relies upon a pre-existing technical prejudice as showing that it was not obvious to take a particular step, it is necessary for the disclosure in the patent to make it plausible that the invention would work or be practical contrary to the prejudice. In the present case neither counsel dissented from that conclusion.

The inventive concept of claim 1 is a non-flammable composition suitable for providing a cooling spray of between ambient temperature and 0^oC consisting essentially of a mixture of water and DME. The inventive concept of claim 2 is such a composition with between 28 and 35% DME. The inventive concept of claim 7 is an aerosol can containing such a composition.

The defendants contend that the claimed inventions are obvious in the light of common general knowledge, and in particular the well-known mineral water cooling sprays. The principal difference between these and the inventive concept of clam 1 is that they use nitrogen as the propellant.

Mr Johnsen accepted that in principle it was obvious to consider making such sprays using a propellant other than nitrogen. By 1992 CFCs were not an option. Propane was not an option because a mixture of propane and water would explode the can. Although that was not a problem with butane, Mr Johnsen said that he would never recommend it since it would not produce an appropriate aerosol spray. Thus the only realistic alternatives were DME, an HFC and carbon dioxide. HFCs were not attractive from a price point of view, since even in the USA they cost four to six times as much as DME. Carbon dioxide would be a similar solution to nitrogen, with the possible disadvantage that it might form carbonic acid. In any event, both nitrogen and carbon dioxide have the disadvantage that, being gases, they are less efficient at producing a fine spray than a liquefied gas propellant.

In my judgment DME was an obvious choice of propellant for a water spray since it is a liquefied gas which was known to be miscible with water. Moreover, it was also obvious to use a DME and water composition with around one-third DME, since that would ensure that was enough DME to give a good aerosol, that the DME would be fully miscible with the water and the composition would qualify as being non-flammable. The skilled person would appreciate that such a composition would achieve a cooling effect when sprayed.

Mr Johnsen did not consider that it would have been obvious to use DME. This was partly because, looking at matters from a US perspective, he thought that the skilled person would still have had some concerns over the safety of DME generally in 1992. For the reasons I have given above, however, I do not consider that a skilled person in Europe would have had any significant concern about the safety of DME as a propellant per se, particularly when incorporated in a non-flammable composition.

More importantly, as I have noted above, Mr Johnsen considered that a DME and water cooling spray was a bad idea. This was because he had serious concerns about the safety of DME in the some of the specific applications envisaged in the Patent. His three principal concerns were as follows. First, a mixture of 3.4% DME and 96.6% air is explosive, and therefore he considered that it would be hazardous to spray a DME and water mixture into a hot confined space such as a car. Secondly, he was concerned about the consequences of inhalation of DME in such circumstances, which could cause nausea and/or drowsiness in the driver. Thirdly, DME is a powerful solvent, and therefore he considered that spraying such a mixture onto the skin could have adverse dermatological effects. As he candidly stated, however, he continued to have these concerns not only after reading the Patent, but also after learning about FNM’s sales of Magicool. Moreover, he accepted that, if these concerns were put on one side, then it would be obvious to make a water spray using DME as a propellant.

In my judgment, these concerns do not amount to a technical prejudice that means that the invention was not obvious. Rather, to the extent that the concerns are justified, they amount to defects inherent in the inventive concept itself. As Mr Johnsen accepted, the Patent does not make it plausible that these concerns do not exist or can be overcome.

FNM relied on two other matters as indicating that the invention was not obvious. The first was that no one had come up with the invention before Mrs Malek. If it was obvious, why had not it not been done before? There are a number of answers to this. First, I have held that the claims were anticipated by several items of prior art, so in that sense it had been done before. Secondly, the evidence suggests that there is not a significant demand for such a product. Thus Magicool has not sold in large quantities, and has only achieved significant sales when supported by television advertising. Mr Johnsen was not aware of anyone else in the world having marketed such a product prior to the present dispute. Thirdly, Mr Johnsen’s evidence suggests that the inventive concept is inherently flawed as discussed above. If he is right, that is more than enough to explain why it was not done before.

Rather more significant to my mind is that evidence was given by Mrs Malek about the reactions of various propellant suppliers and aerosol manufacturers who she approached in the summer and autumn 1992 in her search for a cooling spray product. In short, she approached three leading propellant suppliers, all of whom proposed the use of propellants other than DME (two of them proposing HFC-134a), and four leading aerosol manufacturers, all of whom proposed either water or water and alcohol propelled by nitrogen.

At first blush this appears to be good evidence that it cannot have been obvious to use DME. Upon analysis, however, I do not accept that it does show this, for the following reasons. First, there is the usual problem that it is difficult to be sure that each of the individuals whom Mrs Malek dealt with corresponds to the skilled person to whom the Patent is addressed. For example, the representative of BOC Ltd whom Mrs Malek dealt with described himself as a “marketing assistant”.

Secondly, Mrs Malek’s evidence was that she briefed the people she approached as to what she was looking for in a cooling product. As I understand it, she explained to them the kinds of application she had in mind. Her evidence was that DME was not recommended for safety reasons. For the reasons I have given above, it is very unlikely that the individuals in question can have thought that DME was an unsafe propellant per se. It seems likely that they had similar concerns to Mr Johnsen about the use of DME in the proposed applications. This is supported by Mrs Malek’s evidence as to what happened when she approached Greenhill to make the product. Greenhill raised no concerns when Mrs Malek asked for samples of DME and water aerosols, but did raise concerns about safety when Mrs Malek subsequently disclosed the intended applications to it.

Thirdly, it appears from the contemporaneous documents that Mrs Malek was asking for a non-flammable and non-toxic propellant. In these circumstances it is not surprising that the main propellants recommended to her were HFC-134a and nitrogen. In particular, this would explain why Mr Bleasby of Du Pont recommended HFC-134a to Mrs Malek when, according to LEC’s witnesses, Mr Bleasby was always selling the virtues of DME.

Fourthly, Mrs Malek herself said that she rejected propellants such as HFC-134a because she appreciated that she needed a propellant which was miscible with water. As I have recorded above, DME is the only propellant which is miscible with water. In my view, this means that, if Mr Johnsen’s safety concerns are disregarded, the choice of DME was what is sometimes called in the EPO a “one-way street”.

FNM relies particularly strongly on the fact that one of the people Mrs Malek approached was Mr Bayley at AI, who does approximate to the skilled person. FNM contends that this shows that Mr Bayley failed to make the invention despite having it under his nose. I do not agree. Mrs Malek’s evidence was that she told Mr Bayley that she was looking for a facial cooling spray and he replied that AI had a mineral water spray propelled by nitrogen on the market. She said that she was not interested in such sprays as they were not effective and lost pressure resulting in a coarse spray, but Mr Bayley replied “it depends how you fill”. Mr Bayley went on to suggest a water and alcohol spray propelled by nitrogen, and sent her a sample, but she was unimpressed with this and did not take the matter any further with Mr Bayley. Mr Bayley did not recall this conversation.

It is eminently understandable that Mr Bayley should have tried to interest Mrs Malek in an existing commercial product of AI, or a variant thereof, rather go to the trouble and expense of developing a new one. This does not show that the use of DME was not technically obvious. Furthermore, Mrs Malek’s own evidence was that Mr Bayley told her that AI did use DME, so AI cannot have thought that DME was an unsafe propellant, but at that time Mrs Malek was hoping to find a solution other than DME.

I therefore conclude that claims 1, 2 and 7 are obvious in the light of common general knowledge. I would add that I would reach the same conclusion even if the claims were construed as contended for by FNM.

I have found that these publications anticipated claims 1, 2 and 7 as I have construed them. If the claims were to be construed as contended for FNM, they would not be anticipated. I consider that they would nevertheless be obvious over each of these citations. It would be obvious that they could be used for cooling and it would be obvious to ensure that the temperature of the spray lay between ambient and 0^oC.

It is common ground that the basic aqueous compositions disclosed on page 23 of the Manual, including the one for a “wet” air freshener, are carriers to which one or more active ingredients need to be added. In the light of the common general knowledge regarding air fresheners, I consider that the addition of 0.4 to 1.0% perfume, if appropriate accompanied by a similar amount of an alcohol, would be an entirely obvious step to take. This would result in a composition falling within claims 1 and 2. It would also be obvious to use such a composition in an aerosol can so as fall within claim 7.

FNM contends, in reliance upon Mr Johnsen’s evidence, that it would be obvious to add more alcohol, so as to produce a composition with more than 45% flammable content. That may be so, but it is simply another obvious choice.

Mr Johnsen also said that the air fresheners described in the Aerosol Handbook depended upon the use of an emulsifier, and that simply substituting DME for the hydrocarbon propellant did not work in the sense that the spray was adversely affected. He did not say that they did not work at all, however. Moreover, as I understand his evidence, the problem was that DME was incompatible with the emulsifier. In a 70/30 water and DME composition, however, no emulsifier is needed. Mr Johnsen accepted that the examples in the Patent indicated that there was no problem with an air freshener based on such a formulation.

I would add that my conclusion would be the same if the claims were construed as contended for by FNM.

Although Tan suggests the use of nitrogen or carbon dioxide as a propellant, for the reasons given above DME would be an obvious alternative. Mr Johnsen accepted that, if DME were selected, then 30% would be a suitable proportion. This would result in a composition with a water content of 55.3%, and thus within claims 1 and 2. Tan discloses the use of the composition in an apparatus falling with claim 7. Again, I would reach the same conclusion if the claims were construed as contended for by FNM.

Yudin leaves the choice of propellant to the reader. For the reasons given above, DME would be an obvious choice. This would result in a composition falling within claim 1, but not claim 2. Claim 7 would also fall. Again, I would reach the same conclusion if the claims were construed as contended for by FNM.