Spark decomposition of SF/sub 6/: chemical and biological studies

Abstract

Because electric arcs, sparks or corona can decompose SF/sub 6/ insulators into byproducts having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically decomposed SF/sub 6/. Biological assays using mammalian cell culture systems have revealed that SF/sub 6/, spark-decomposed under specific experimental conditions, can produce cell death. Chemical analysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and byproducts. Biological testing of individual byproduct mixtures has indicated that these major decomposition products may not account for the majority of the cell-killing effects seen in the assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be produced and accumulate under the specific decomposition conditions and that this compound may be a major contributor to the observed cell lethality. It is concluded that testing of samples from commercial facilities and assays of decomposed gas after ameliorative treatments would both be appropriate investigations. >