On the run

Health and environmental concerns spell curtains for some waterproof mascara and other cosmetics.

- VERONIKA MEDUNA

Most people applying makeup probably don't stop to ponder how hazardous the swipes of lipstick or mascara might be. But beauty products are chemical concoctions, formulated to cover skin blemishes or stick to eyelashes for hours without running, clinging on through a sweaty night out dancing or a weepy movie. To give cosmetics this durability and water resistance, some manufacturers use a group of substances commonly known as "forever chemicals", or PFAS.

There are thousands of distinct compounds in the PFAS (per- and polyfluoroalkyl substances) group and all are synthetically manufactured chemicals that contain links between carbon and fluorine atoms. The carbon-fluorine bond is one of the strongest in organic chemistry and it gives PFAS some interesting properties. They repel both water and fats and tolerate heat, which means they are stain-resistant, grease-resistant and waterproof.

This in turn makes them useful in a wide range of applications, including food packaging, non-stick cookware, electronics, refrigerants, stain-proof or waterproof textiles - and cosmetics.

But the strength of this bond also means PFAS don't break down easily. Instead, they build up in the environment and accumulate in our bodies. For some PFAS compounds, evidence of health risks emerged as early as the 1980s, albeit not publicly, associating high levels of exposure with certain cancers, birth defects and thyroid or immune malfunction. Research to determine the health impacts of lower exposures such as through regular use of PFAS-containing beauty and personal care products - is continuing, but their persistence in the environment has prompted regulators in the US and Europe to propose bans on their use.