They stop your food from sticking to the pan. They prevent stains in clothes and carpets. They help firefighting foam to extinguish fires. But the very thing that makes "forever chemicals" so useful also makes them dangerous.

Forever chemicals—the catchier name for the class of chemicals known as PFAS, per- and poly-fluoroalkyl substances—don't break down in the environment. Since we invented and began using them in the 1940s, these chemicals have stuck around, contaminating water and soil. And when they make it into our bodies, they can bind to proteins and accumulate in organs, which may increase your cancer risk or damage your health. Major manufacturers are now facing lawsuits over the potential health impact of the chemicals.

How do they make it into your body? There's been a lot of concern over their presence in drinking water. But there's another risk—food. Like many countries, Australia has long used biosolids as fertilizer. Made from processed stormwater and sewage, this soil-like substance adds vital nutrients to our notoriously poor soils.

The problem is, forever chemicals are now in biosolids. Even though the levels are low, authorities are expected to soon make a precautionary change to regulations which would prevent the use of biosolids, as we now understand crops can accumulate these chemicals and pass them on to us.

Thankfully there are ways of making these chemicals harmless.