Atmospheric loss processes of 1,2-dibromo-3-chloropropane and trimethyl phosphate

Abstract

The reactions of 1,2-dibromo-3-chloropropane (DBCP) and trimethyl phosphate with O/sub 3/ and the OH radical have been investigated at 296 +/- 2 K and atmospheric pressure of air by long-path Fourier transform infrared spectroscopic and gas chromatography-mass spectrometry techniques. For reactions with O/sub 3/, upper limits to the rate constants of < 3 x 10/sup -20/ cm/sup 3/ molecule/sup -1/ s/sup -1/ for 1,2-dibromo-3-chloropropane and < 6 x 10/sup -20/ cm/sup 3/ molecule/sup -1/ s/sup -1/ for trimethyl phosphate were determined, showing that reaction with O/sub 3/ is not an important atmospheric loss process for these compounds. With the use of relative rate techniques, OH radical reaction rate constants of 4.4 x 10/sup -13/ cm/sup 3/ molecule/sup -1/ s/sup -1/ for 1,2-dibromo-3-chloropropane and 7.4 x 10/sup -12/ cm/sup 3/ molecule/sup -1/ s/sup -1/ for trimethyl phosphate were obtained, leading to calculated tropospheric lifetimes of approx.55 and approx.3 days, respectively, for the reactions of these compounds with OH radicals. CH/sub 2/BrCOCH/sub 2/Cl has been tentatively identified as a product of the reaction of OH radicals with 1,2-dibromo-3-chloropropane. 14 references, 3 figures.