Fluorinated ethylenepropylene - type of material commonly known as Teflon - used in clear form as an overlay for chemical suit visors, to provide extra chemical protection. (Also known as Fluoroethylene Polymer)
DuPont (The Miracles of Science), Literature & Technical Information, Industrial Personal Protection Glossary, Wilmington, DE, USA 2010http://www2.dupont.com/Personal_Protection/en_ HK/tech_info/glossary_industrial.html, (IndPP - Amer) {49}