Formation of organic indoor air pollutants by UV-curing chemistry

UV-curable systems for manufacturing of furniture and parquet form a major and growing field in radiation curing. Numerous types and combinations of photoinitiators have been developed for crosslinking of acrylated systems and unsaturated polyesters. The properties of the photoinitiators being used in these materials must fulfill requirements like low toxicity, low odor and high reactivity. However, volatile reaction products being produced during the photochemical process contribute to the pollution of indoor air by emission from the surface and may cause strong odor and adverse health effects. Therefore, the release of photoinitiators, fragmentation products and monomers from UV-cured coatings was studied as a function of time under realistic living conditions in emission test chambers and cells. Main components detected in the chamber air were benzaldehyde, cyclohexanone, benzophenone and acrylate monomers. The area-specific emission rates SERA were found to be strongly dependent on the climatic conditions.