Atmospheric Lifetimes and Fates of Selected Fragrance Materials and Volatile Model Compounds

Fragrance materials are semivolatile organic compounds widely used in consumer products. Despite their generally low volatility, it is expected that a fraction of these compounds will volatilize into the atmosphere, where they can photolyze, react with OH radicals, NO3 radicals and O3, and/or undergo wet and dry deposition. Using relative rate methods, rate constants have been measured at 296 ± 2 K for the gas-phase reactions of OH radicals, NO3 radicals, and O3 with the fragrance materials 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-naphthalenyl)ethanone (OTNE), acetyl cedrene [(3R-(3a,3ab,7b,8aa))-1-(2,3,4,7,8,8a-hexahydro-3,6,8,8-tetramethyl-1H-3a,7-methanoazulen-5-yl)ethan-1-one], and HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethycyclopenta-[γ]-2-benzopyran) as well as with isochroman which is structurally related to HHCB. Measured rate constants (in cm3 molecule-1 s-1 units) are OH radical reactions [OTNE, (9.85 ± 0.88) × 10-11; acetyl cedrene, (7.7 ± 1.6) × 10-11; HHCB, (2.6 ± 0.6) × 10-11; and isochroman, (3.7 ± 0.6) × 10-11], NO3 radical reactions [OTNE, (1.71 ± 0.19) × 10-11 and acetyl cedrene, (4.1 ± 1.0) × 10-15], and O3 reactions [OTNE, (2.1 ± 0.5) × 10-18 and acetyl cedrene,