Formation of ozone-initiated VOCs and secondary organic aerosol following application of a carpet deodorizer

Volatile Organic Compounds (VOCs) emission and Secondary Organic Aerosols (SOA) formation from a water-based carpet deodorizer were investigated in a 20 m(3) walk-in climate chamber with and without a textile carpet installed. The deodorizer was tested under near-realistic user conditions at low (<2 ppbv) and high (similar to 50 ppbv) ozone concentrations and controlled micro-environmental parameters. Fifty grams of the deodorizer was pump sprayed onto 2 m(2) inert stainless steel surface or carpet in order to mimic normal use. Characterization of primary VOCs and ozone-initiated products was performed by air sampling on Tenax TA followed by TD-GC/MS analysis and on DNPH cartridges followed by liquid extraction and HPLC/UV analysis. SOA formation was monitored simultaneously by means of high-time resolution instruments. Emission testing onto steel plates at similar to 50 ppbv ozone showed the decay of reactive VOCs (i.e., dihydromyrcenol and linalool) concurrent with the consumption of ozone and formation of oxygenated reaction products (i.e., acetaldehyde, acetone and 6-methyl-5-hepten-2-one) and an increase of SOA. Emission testing on carpet at similar to 50 ppbv ozone showed a significant ozone removal and an increase of nonanal and dodecanal, but without detection of oxygenated products and SOA formation. Modeling of the reactive VOCs from the carpet experiment showed they followed a first order decay.