THE ATMOSPHERIC STABILITY OF POLYBROMINATED DIBENZO-PARA-DIOXINS AND DIBENZOFURANS

In order to study the photochemistry of polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs) dilute emissions from the combustion of polyurethane foam containing polybrominated diphenyl ethers (PBDPEs) were introduced into 25 m3 outdoor Teflon film chambers and aged in the presence of sunlight. PBDDs and PBDFs were found primarily in the particulate phase where they were stable or degraded slowly over a period of hours. The half life of the reaction on actual soot particles agreed better with the predictions of laboratory solid phase then laboratory solution phase experiments.