What are perfluoroalkyl substances (PFASs), such as PFOS and PFOA?
PFASs are a class of synthetic chemicals with numerous industrial and commercial applications with an extensive number of compounds that can be included in this classification. These compounds are primarily carboxylic acid or sulfonic acids (sulfonates) with completely fluorinated alkyl groups of various lengths (can occur as linear or branched chains). PFCs and perfluorinated alkyl acids (PFAAs) are additional terms referring to this class of chemicals. PFASs have been used in a wide range of consumer products, have industrial applications in the electronics and aerospace industries and in aqueous film-forming foams (AFFFs) used for firefighting training. The two most commonly encountered compounds in the environment are PFOS and PFOA. Due to increasing concern for potential health effects associated with these compounds, PFOS is no longer produced in the United States and PFOA is currently being phased out of production.
Environmental and Health Impacts of PFOS/PFOA?
PFAS compounds, especially the longer chain chemicals, do not easily degrade and can persist in the environment for a significant amount of time. Due to widespread use, PFAS such as PFOS and PFOA are prevalent throughout the environment, resulting in contamination of drinking water, surface water, and soil. The highest concentrations are typically encountered in areas in close proximity to facilities where firefighting training has occurred, industrial production facilities, and discharge from waste water treatment plants (both in effluents and bio solids). As a result of their widespread presence in the environment, human exposure to PFAS compounds occurs through use of commercial products, drinking water, air, and dust. Studies have indicated that these compounds are present in virtually all individuals. PFAS have been linked to potential health effects including cancer, disruption of endocrine activity, reduced immune system function and impairment of various organs. The EPA and several States have developed human health guidelines for exposure to PFOS and PFOA. Several years ago, manufacturers began to replace the previously produced long chain PFASs with short chain PFASs. Data on human health effects for the shorter chain PFASs is limited, but adverse effects from exposure have been indicated in some studies.