Solvents and Ozone

Hydrocarbon and oxygenated solvents do not play a part in creating the ozone hole problem in the stratosphere. Under certain conditions, solvent emissions may contribute to create ground-level ozone. However, the solvents industry has substantially reduced its emissions and continues to contribute to the improved air quality in Europe.

Ozone can be found near the “ground level” (the “tropospheric ozone” commonly referred to as “smog”) or high up in the stratosphere. Stratospheric ozone protects humans from excessive ultraviolet rays and helps stabilise the earth’s temperature. Oxygenated and hydrocarbon solvents do not play a part in the stratospheric ozone problem. This is because solvents, like natural VOC emissions, are rapidly cleaned from the lower atmosphere by photochemistry. This means that they never reach the stratosphere.

Ground level ozone is formed when NOx and VOCs react with sunlight and heat. It also occurs naturally all around us. Under certain weather conditions, too much ozone is produced and results in reduced air quality. Ozone peaks, which are temporary, primarily occur in summer and are pertinent to certain regions in Europe.

Between 1990 and 2000, VOCs have been reduced by 30% (Reference: the Co-operative Programme for Monitoring and Evaluation of the Long-Range Transmission of Air Pollutants in Europe - EMEP/MSC-W Note 1/2002, July 2002). Improved solvent management and solvent efficiency means that on average it now takes only half as much solvent to produce a finished object as it did in 1980. Furthermore, industrial VOC emissions have been reduced by a factor of two (47% on average and up to 64% in some sectors) in about 10 years.

The extent to which NOx and VOCs participate in ozone formation varies. In order to develop efficient strategies to improve air quality, the EU industry is working on reducing emissions as well as understanding what contributes the most to ozone formation. Reducing NOx would appear to be the most effective way to continue to reduce ozone levels in the EU.

The solvents industry is playing its part in reducing ozone peaks by:

• Helping to develop new means of deterring solvents with negligible photochemical reactivity.
• Helping to create new formulas for coatings and other products with low ozone forming potential whilst maintaining high quality standards.
• Researching ozone formation and targeting efficient solutions such as promoting abatement techniques.
• Working with EU and national regulators to encourage development of products that meet environmental needs without compromising performance.