JACC Report 48 – Hexafluoropropylene

Abstract

JACC 048 : Hexafluoropropylene (CAS No. 116-15-4) | October 2005

This report has been produced as part of the ECETOC Joint Assessment of Commodity Chemicals (JACC) programme. It presents a critical evaluation of data on the toxicity and ecotoxicity, and environmental fate and impact of hexafluoropropylene (HFP). A hazard/risk assessment is required under current OECD/EU schemes. In the USA, HFP is included in the EPA (Environmental Protection Agency) Chemical Right-to-Know Initiative . HFP is a chemical intermediate used in the synthesis of fluoropolymers, fluoro-elastomers and also fluorinated oils and greases. It is a colourless gas that is only slightly soluble in water. Any HFP released to the environment will be found mainly in the air, where it will be broken down by reaction with hydroxyl radicals to trifluoroacetic acid, hydrogen fluoride and carbon dioxide. HFP is unlikely to bioaccumulate. The environmental risk from exposure is low, since only a small amount is released into the environment. HFP does not deplete the stratospheric ozone layer. The global warming impact of HFP is insignificant, other than by contributing to carbon dioxide concentrations on atmospheric breakdown. HFP has a low acute toxicity in laboratory animals. In repeated exposure studies, the kidney was the principal target organ, as manifest by an increase in relative kidney weight. In one study, there was also a decrease in relative spleen weight. Although no standard reproductive or developmental toxicity studies have been conducted, the reproductive system does not appear to be a target of HFP toxicity and it is not considered that there is a need for any further studies of these end-points. Genotoxicity studies have generally been negative, suggesting a low level of concern. However, recent findings with the structurally related tetrafluoroethylene of chronic toxicity, including certain tumours in life-time studies in mice and rats at high exposure levels, may indicate the possibility of carcinogenicity for HFP. HFP is manufactured in closed systems and occupational exposure, limited to specific job classifications, is expected to be low. It is thus considered to be of low potential risk. Company internal occupational exposure limits range from 0.5 to 2 ppm (3 12 mg/m3). There is no known direct consumer exposure to HFP. Consumer exposure is negligible, arising only from low levels of residual monomer in end-use polymeric products.