EnSolv® The Popular Alternative to Trichloroethylenee
What is EnSolv?
EnSolv is a patented formulation precision cleaning solvent for use in applications where high integrity vapour cleaning is needed. Aerospace, Medical, F1 Racing, Electronics for instance. EnSolv products are a safer alternative to the carcinogen Trichloroethylene (TCE). The main constituent of EnSolv is n Propyl Bromide (nPB) and all of the health hazards of EnSolv derive from this component.
Is nPB considered to be a carcinogen?
nPB is not a carcinogen. There have been many studies over the years and there has never been an indication that it has a carcinogenic effect. In the United States of America it is not listed as a carcinogen by IARC or the NTP. Enviro Tech recently commissioned an In Vitro Human Cell Bioassay of Commonly Used Vapour Degreasing Solvents. The work was peer reviewed and published in Toxicology and Industrial Health 2006; 22: 301_315. Copies are available on request. The results are consistent with previous animal testing and confirm that EnSolv has no mutagenic effect within the exposure levels tested. It confirms the hazards with TCE and also indicates potential mutagenic hazards with using HFE’s for which there is very little animal testing data available.
Why is EnSolv considered to be safer than Trichloroethylene (TCE)?
TCE is a known category 2 carcinogen with the R45 label - May cause Cancer. It is also considered to be a reproductive toxin, although is not labelled as such since the HSE consider that classifying it as a carcinogen would mean that employers/users would not need to take further precautions since a carcinogen is the most toxic.
What is the classification for n-Propyl Bromide (nPB)?
In 2005 the substance, n Propyl Bromide was reclassified from:
R10, R20, Xn
to
R11, R60, R48/20, R63, R36/37/38, R67, T
This classifies it as Reprotoxic and puts it into the group of CMR’s (Carcinogens, Mutagens and Reprotoxins).
We believe that this classification is flawed and our case is shortly to be heard by the European Court of First Instance, probably during 2007. The evidence put forward for a category 2 reproductive toxin is not sufficient to justify this classification. It was driven through mainly on the basis of “Precautionary Principle” which is not allowed in law
Why is the current classification for nPB wrong?
A similar chemical, Iso Propyl Bromide was cited as a known fertility toxicant to justify the change. Studies now show that the Iso Propyl Bromide metabolises in a completely different way to nPB and therefore direct comparisons cannot be drawn. More recent work shows that any fertility effect, which is first seen after exposure to > 500ppm, is based on the secondary narcotic effect and not a direct effect. Therefore we believe that the R60 classification is not sustainable.
With n-Propyl Bromide the major constituent, how can you classify EnSolv differently?
EnSolv is a preparation and not a substance and is therefore subject to the Preparations Directive 1999/45/EC. This is implemented into UK law by CHIP regulations, although the EU directive always takes precedence. In classifying and labelling EnSolv we have referred to Article 6(3) of Directive 1999/45/EC. This allows us to classify the product according to its effect on man. We have a number of case studies from around the world demonstrating that there is no evidence of reproductive toxicity at the relatively high exposure levels recorded. These levels are 5-10 times those typically found around a vapour degreaser. We have therefore maintained our original classification of Xn R20 Harmful by inhalation and R36/37/38 Irritating to eyes respiratory system and skin
How is the OEL for EnSolv established?
In the old system, TCE had a Maximum Exposure Limit (MEL) of 100 Parts Per Million (ppm). By definition this means there is no safe level but at less than 100ppm the risks were considered manageable. In other words it is possible to develop cancer at much lower levels but the chances were reduced. An Occupational Exposure Limit (OEL) gave limits below which no effects were seen.
nPB does not have an official OEL although various organisations have issued recommendations. Based on work commissioned by Enviro Tech International Inc.(ETI) (Duoll and Rozman, Stelljess and Wood) we quote a maximum of 100ppm TWA. Copies of these papers are available on request. ACGIH recently published a Threshold Limit Value of 10ppm maximum but this figure has been challenged by ETI and even the Environmental Protection Agency (EPA) in the USA have questioned the ultra cautious values used. The EPA has recently given nPB SNAP (Significant New Alternative Policy) approval making it a safe alternative for vapour degreasing. They quote it as less toxic than TCE. Their recommended exposure limit of 25ppm maximum is based on the Duoll and Rozman report but with much higher uncertainty factors and is close to the generally accepted solvent levels found in practice around vapour degreasers.
How does the Solvent Emissions Directive (SED) affect the use of EnSolv?
DEFRA within the recent AQ 15 (07) have highlighted that nPB is classified R60 Toxic, however as explained we classify EnSolv as a preparation R20 Harmful Xn. Concerning the SED, any substance or preparation classified as R45, R46, R49, R60 or R61 is a category 2 CMR and subject to consumption figures of greater than 1 tonne per year, must be replaced as far as possible by less harmful substance or preparation in the shortest possible time. This is normally within 6 years of that substance or preparation being so classified, in the case of TCE by mid 2008. A substance reclassified by the 29th ATP such as nPB should be substituted as far as possible before Oct 2011. An R20 classified product can be consumed up to 2 tonnes without restriction.
Is EnSolv flammable?
NO
nPB was reclassified in the 29th ATP as R11 Highly flammable following an invalid test result using a method inappropriate to the flash point range. When the same test method was used on other common vapour degreasing solvents, similar flash points were found. If those flash points were used to define their flammability then all would be Flammable (R10) or Highly flammable (R11)
|
| Solvent |
Flash point |
Derived Flammability |
| |
|
|
| Trichloroethylene |
+24ºC |
R10 |
| Methylene Chloride |
-5.5 ºC |
R11 |
| HFE 72 DE |
-9 ºC |
R11 |
| HFE 71 DE |
-16 ºC |
R11 |
| HFE 71 A |
-14 ºC |
R11 |
| nPB |
-5 ºC |
R11 |
When other appropriate methods are used, no flash point can be found. However the HSE are not prepared to reclassify those solvents or change the R11 assigned to nPB.
EnSolv being a preparation can be self classified and ETE have had our products tested by an independent GLP test house specialising in flammability and risk assessment who confirm they do not have a flash point and are therefore not flammable.
Why should I use EnSolv?
We are concerned that industry is continuing to use a known carcinogen such as TCE when there are safer products such as EnSolv® available. Employees and the general population are being exposed to the risk of cancer, which once developed is a permanent threat to life. Some small risk of fertility impairment which is transitory and can be managed is surely the way forward. As a company we are committed to Responsible Care and our technical specialist distributors promote solvent reduction programs to reduce the effect on the environment
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