Rumours Surrounding European EnSolv Ban Are False

There have been reports circulating recently stating that EnSolv is to be banned in Europe because of its ozone depletion potential (ODP). However, this is not true; as part of its continuing commitment to the Montreal Protocol process, the European Parliament monitors known and potential ozone depleting substances used in refrigeration, fumigation and solvent-cleaning processes to ensure that the European Union meets its international responsibilities.

As a result of the rapid increase in usage of EnSolv for vapour degreasing, the use of the main constituent, n-Propyl Bromide (nPB), will, in future, be monitored but not restricted or banned. Volatile halogenated compounds are the substances that most affect the ozone layer. Compounds containing fluorine, in particular, are under constant review as flourine is the most reactive of the halogens.

The original fluorocarbons, CFC R11 and 113, sold in Europe as Freon and Arklone, were used as refrigerants, aerosol propellants and cleaning solvents and were the original reasons for ozone depletion; they were phased out of use during the 1970s and 1980s, allowing the ozone layer to slowly recover. Many others have been restricted and banned since this time, the most recent, used for cleaning, being HCFC 141b. When it was first introduced, it was assumed to be an acceptable replacement.

However, further work over the following years established that it, too, was depleting the ozone layer and it was banned, together with other fluorine-based liquids used in refrigeration and air conditioning (the 'F' gases). Now, new fluorine compounds and blends are being offered as alternatives for cleaning, such as HFEs and HFCs, and only time will tell whether these will also cause problems with ozone depletion and global warming. EnSolv, a patented stabilised nPB-based formulation, is the drop-in substitute for the carcinogen trichloroethylene in vapour degreasing.

This process is used throughout the manufacturing industry as it offers many advantages when compared to alternative technologies such as water cleaning. First, EnSolv is very fast, with a cycle time of three to five minutes and comparative water cleaning cycles of 30 to 60 minutes. It also carries out eight to 10 loads per hour compared to water cleaning cycles of one to two per hour. Additionally, it is said to be energy efficient, using only 50 per cent of the energy requirements of aqueous systems with savings in C02 emissions.

Solvent cleaning with EnSolv - when all the factors are considered - is claimed to be more economical in terms of money and its effects on the environment. Vapour degreasing with fluorocarbon solvents is unsatisfactory as a result of their low vapour temperatures. EnSolv, however, is said to offer better levels of vapour cleaning. With a boiling point of 70C, EnSolv allows parts that do not corrode in storage to be handled immediately. Very little monitoring is needed as the stabiliser system, patented worldwide, is self regulating.

Sales of EnSolv have grown rapidly over the past two years, which is why the European Commission has to monitor the increased consumption. As with many other substances, nPB is under constant review by the UN Environmental Panel (EP) to ensure that it is not affecting the ozone layer. The UN EP and the US EPA asked for a 3D study on the effects of very short-lived halogenated compounds from Prof Don Weubbles: the originator of ODPs. This report, which is due for publication soon, will provide comparative ODPs for nPB and other commonly used halogenated solvents. Until now, this has not been possible as a result of the difficulties of comparing different atmospheric models.

The report will, subject to the editor's agreement, be published following peer review and demonstrates that nPB will have a minimal impact on the ozone layer and that it is no cause for concern. As nPB is a suitable drop-in replacement for the other solvents used in vapour degreasing, it has been the subject of innumerable studies for its environmental and toxicological effects. It is not considered by any of the international agencies as a carcinogen and, in many parts of the world, it is becoming the solvent of choice for managements that do not wish to expose their workforces to carcinogens. However, it has been incorrectly classified as a Category 2 reproductive toxin in Europe.

The manufacturers of EnSolv have been challenging the European Commission for the last five years to justify their actions in court. The UK Health and Safety Executive (HSE) has to implement and enforce this classification and a judicial review has been requested, which has now been suspended by mutual agreement until the European Court of Justice (ECJ) has made a judgement. Judges in Belgium have also asked the ECJ for a ruling on the classification, which should be forthcoming in the near future. Envirotech, a manufacturing company, has self classified EnSolv as non-flammable and R20 harmful by inhalation; it expects this to be confirmed by the court when a judgement is made.