Polytetrafluorethen

The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has evaluated polytetrafluoroethene [9002‐84‐0] to derive a maximum concentration at the workplace (MAK value), considering all toxicological endpoints. Available publications are described in detail. As polytetrafluoroethene is an insoluble and chemically inert polymer, showing no systemic toxicity after subchronic oral dosing, polytetrafluoroethene granular dusts are considered to be biopersistent. According to the mechanistic model, chronic inhalative overload of alveolar particle clearance results in particle‐induced inflammation and diverse proliferative tissue changes in lungs. The general threshold limit value and all its classifications for the respirable and inhalable fractions are applied to polytetrafluoroethene: For the respirable fraction, a MAK value of 0.3 mg/m3 × density (2.2 g/cm3) is set with Peak Limitation Category II and an excursion factor of 8. It is classified in Carcinogen Category 4 and in Pregnancy Risk Group C. For the inhalable fraction, a MAK value of 4 mg/m3 is set. The inhalable fraction is also assigned to Pregnancy Risk Group C because polytetrafluoroethene is an insoluble and inert polymer, which is not systemically toxic after oral dosing. There are no data on genotoxicity, sensitization or dermal absorption. As polytetrafluoroethene is an insoluble polymer, genotoxic and sensitizing effects and a significant contribution of skin absorption to systemic toxicity are not expected.