Summary:  A new type of exclusionary endorsement is being made available under the ISO program to address exposures of PFAS chemicals. This is an early introduction to the filing, as the endorsements will not be available until at least May, 2023.

PFAS is the abbreviation for perfluoroalkyl and polyfluoroalkyl substances, which are described by the National Institute of Environmental Health Sciences (NIEHS) as a "large, complex, and ever-expanding group of manufactured chemicals that are widely used to make various types of everyday products." According to the Interstate Technology Regulatory Council (ITRC), some industries and products that incorporate the use of PFAS include, but are not limited to, automobiles, pesticides, cosmetics, food processing, textiles, furniture and household products. While potential health impacts that exposures to PFAS could lead to are still being researched and thus remain uncertain, they have come under scrutiny due at least in part to their environmental presence, because they: 

• do not break down in the environment,
• can move through soils and contaminate drinking water sources,
• build up (bioaccumulate) in fish and wildlife.

The CDC has more information on PFAS under their National Biomonitoring Program, contained in this Fact Sheet. The substances are found in rivers and lakes, and also in many types of land and water animals. .

This discussion provides an analysis of the umbrella PFAS exclusion endorsement, CU 34 54, and the excess liability exclusion endorsement, CX 21 97 The underlying CGL exclusion endorsements were previously introduced and are discussed here.