Per-and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals widely used in firefighting foams and many industrial and consumer products due to their exceptional resistance to heat, water, oil and chemicals.

Often called "forever chemicals," PFAS do not naturally break down and can remain in the environment for decades. 

Once released, they can contaminate soil, groundwater, waterways and ecosystems, spreading far beyond their original source.

PFAS can also accumulate in the human body over time. 

Studies have linked exposure to certain PFAS compounds with serious health concerns, including some cancers, liver and kidney damage, immune system impacts, thyroid disorders and developmental effects.

As a result of their persistence, mobility and potential health risks, governments around the world are tightening regulations and phasing out PFAS - containing products, particularly firefighting foams.