What are PFAs?

PFAS are a large group of manufactured compounds that have industrial and consumer applications, often as surfactants, coatings, and treatments to repel oil, grease and water.  They are resistant to heat, water, and oil. There are more than 4,000 such substances, grouped in various subclasses. Some are persistent in the environment and in the human body, and so are of concern nationally and internationally. They are resistant to environmental degradation. They also bioaccumulate in the tissues of living organisms for long periods of time.