A question of solvents
Keywords: European Solvents Industry Group, Solvents, Regulations,Environment
John Bean, technical editor of Pigment & Resin Technology , talks to Nigel Sarginson Plate 1 , recently appointed chairman of the European Solvents Industry Group.
Plate 1Nigel Sarginson, chairman of the European Solvents Industry Group
JB
How do you see the role of the European Solvents Industry Group (ESIG)?
NS
The European Solvents Industry Group provides a focal point for the solvent industry’s commitment to responsible care and product stewardship. It ensures a central information point for the industry, customers and external audiences. It acts on behalf of the industry representing its concerns and views to all interested groups. By working with users, industry partners, regulators and other interested parties, the group aims to develop and promote best practice in solvent usage and health, safety and environment protection.
Recent examples of this include:
Solutions for the future conference (addressing the Solvent Emissions Directive) held in March 1999.
Publication of ESIG Best Practice Guide-lines – first guideline– Measuring Solvent Vapour Concentration in the Work Environment.
Distribution of the ESIG Abatement Advisor (also downloadable from the ESIG Website: www.esig.org) PC based software that enables emission abatement options to be identified.
Sponsorship of the ESIG Solvent Stewardship Awards, with the first awards having been made in March 1999.
Working in partnership with users and regulators in the development and implementation of the Solvent Emissions Directive. Throughout the discussions ESIG have supported cost effective reduction of solvent emissions, which bring tangible environmental benefits.
JB
With the EU Solvent Emissions Directive soon to come in force, what solvents do you consider are likely to disappear eventually from coatings, inks and adhesive manufacturers’ formulations?
NS
The EU Solvent Emissions Directive was adopted by the Council of Ministers on March 11, 1999, and is now undergoing a two year transposition period into member state law. The Directive specifies emission limit values for downstream industrial users; existing operations have until 2007 to comply with these emission limit values. The Directive does not prohibit the use of specific solvents but allows the user the flexibility to reduce emissions or use alternative technologies or a combination of both. The Directive does set very challenging objectives for industry and it will be essential to retain the flexibility referred to above to ensure that industry can manage the cost impact. The Directive singles out substances which are classified as carcinogens, mutagens or toxic to reproduction and calls for these to be replaced and also imposes more stringent emission limit values for these materials. This requirement has no impact on commercial hydrocarbon and oxygenated solvents marketed today since none are classified as such. For a number of years there has been a trend in adhesives to move away from n-hexane containing solvents for health reasons and this is likely to continue, although not specifically due to the Solvent Emissions Directive. In certain coatingsproducts there has been a move to low aromatic solvents on worker health and comfort grounds and this trend is also likely to continue.
JB
Some people are saying that coating manufacturers can get around any restrictions by limiting their use at individual manufacturing sites to be below the threshold limit required for registration.
NS
The Solvent Emission Directive does not impose “any restrictions”on the use of solvents, rather it provides emission limit values to control emissions from industrial operations. The threshold consumption of solvent for the paint coatings manufacturing industry below which a specific installation is exempt from the Directive is 100 tonnes per year. This level (together with thresholds for other sectors) has been agreed to ensure that very small producers are not unfairly affected by the legislation, since they contribute minimal amounts of VOC emissions from this level of solvent usage.
The threshold for some other industrial users includes five tonnes per year for adhesives and 15 tonnes per year for coating of wooden surfaces.
JB
One sometimes has the impression that those responsible for recent environmental legislation on the ever restricting use of solvents mistakenly believe that waterborne coatings, adhesives, etc. will eventually replace all solvent based materials. Adhesion is but one property that seems to suffer with waterborne coatings, and there is still some way to go on achieving a high gloss. Would you like to comment?
NS
Yes! As solvent producers we also occasionally get that impression! However,since solvents provide unique performance characteristics cost effectively, and in a safe and environmentally acceptable manner, we firmly believe that they are here to stay.
For example, ESIG has carried out life cycle assessment studies on alternatives to solvent based coatings for the Humber Bridge. The study found that to protect the bridge with most new paint systems (including water-based paints) would first require stripping off the old coating followed by regular complete respraying. This would result in a far higher use of resources and emissions (including VOCS) than using the current solvent based system which would protect the bridge adequately, simply through the normal maintenance process of touching up stressed patches.
Another study carried out by ESIG compared a water-based and solvent-based car basecoat. The study compared 30 criteria covering the manufacture of the raw materials, the paints and their application in the assembly plant. The results showed that there is no environmental benefit to either water-based or traditional technology using proper abatement controls.
Most recently an ESIG Solvent Stewardship Award was made to the European Coil Coating Association who clearly demonstrated that solvents are the economically and environmentally preferred option when it comes to coating steel.
Full details of these examples can be found on the ESIG website(www.esig.org). ESIG believes strongly in “fitness for purpose” and recognises that in some instances it may be appropriate to use a low solvent-based or water-based technology. It is of course important that the safety, health and environmental impact of such alternatives is fully assessed.
JB
Following on from the above, do you think that continued growth in water-based coatings, high solids, radiation curing (all of which will still require some organic solvents), plus powder coatings, will drastically reduce the number of solvent manufacturers, leaving only the major multinationals?
NS
ESIG recognises the advances in these coating technologies, but solvents will still play an important role, including in decorative coatings where high gloss is required.
ESIG also believes there is a strong and healthy future for the solvents business(see the answer to the previous question). The future structure of the solvents industry will be determined by many market related and business factors of which safety, health and environmental aspects are just one element.
JB
In the field of solvent cleaning of metal substrates prior to painting,1,1,1-trichloroethane rightly becomes a prohibited solvent, primarily because of its carcinogenic properties. However, this appears to have given all the chlorinated solvents a bad name, including trichloroethylene and methylene chloride (which are not carcinogenic). Do you foresee a long-term future for these chlorinated hydrocarbons?
NS
ESIG has been created as a single focus for information on oxygenated and hydrocarbon solvents. Chlorinated solvents are outside our remit and the industry group responsible for these products is the European Chlorinated Solvents Association (ECSA). Please contact them for information on chlorinated solvents.
JB
A short time ago some were putting their faith in n-propyl bromide as an alternative solvent to those whose use is now restricted. Others are urging caution, saying more toxicological tests must be undertaken. Has the European Solvents Industry Group experience of n-propyl bromide as a solvent?
NS
n-propyl bromide does not fall within the scope of oxygenated and hydrocarbon solvents and so ESIG cannot comment specifically on this product. More generally speaking ESIG clearly supports that any proposed alternative solvents should be subject to a thorough safety, health and environmental evaluation prior to being put forward as replacements. Oxygenated and hydrocarbon solvents have a long history of safe and environmentally acceptable use and have been subject to extensive toxicological and environmental testing.
Further details are available from: European Solvents Industry Group. Tel: +44 (0) 171 584 0122.
