Hazardous halogenated substances formed during combustion processes

The results of the emissions from combustion processes and/or from fire accidents show the risk to man and his environment and thus the need for strict legislation and critical analysis of unwanted compounds. These substances or their thermolysis products are often due to incomplete combustion or may result from the interaction of various substances.

In the following we report the formation of octachlorostyrene (OCS) and of high‐toxic substances such as polybrominated dioxins (PBrDD's), dibenzofurans (PBrDF's) by the combustion.

In order to determine a possible source of the non‐manufactured compound OCS, we conducted several model experiments in a combustion chamber at various temperatures from 400 °C to 800 °C. The thermolysis of chlorinated solvents like chloroform or of chlorinated aromatice like pentachlorobenzene produced—among other chlorinated substances—OCS as one of the major products.

Analogous combustion experiments with polyester plastics containing decabromodiphenylether as flame retardant and antimony trioxide as Synergist led to PBrDD's and PBrDF's. Here antimony trioxide seems to play an important role because in absence of this oxide, PBrDD's and PBrDF's were not found in our experimental conditions.