Mounting evidence shows that the emergence of seemingly safer and less persistent “alternatives” to legacy PFASs may pose the same problems as their predecessors. An ineffective and broken regulatory system and weak environmental laws in the United States have done little to stymie the ever-revolving chemical treadmill that has contaminated entire communities and put public health at risk. The federal government must take immediate action to strengthen regulations to stop PFASs from contaminating our environment, and to remove them from our drinking water.
Per- and polyfluoroalkyl substances are a large group of related synthetic compounds that were introduced in the 1940s and 1950s, when chemical regulations were even weaker than today. Due to their stable chemical structure, PFASs are long-lived substances with the ability to repel both water and oil, making them extremely useful in a wide variety of applications and products. However, the characteristics that have made them attractive for use in an array of products are the very ones that have led to their wide-spread contamination of the environment and people.
As of 2018, at least 478 PFASs had been reported to the U.S. Environmental Protection Agency (EPA) as being used in U.S. commerce. Other sources report that thousands of PFASs have been produced and used by various industries, in both the United States and around the world.
The most studied and pervasive chemical forms are per- fluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). PFOA has been used in the production of the chemical polytetrafluoroethylene (PTFE), best known by the commercial name TeflonTM, which was first synthesized in 1938 by a DuPont scientist and came into widespread use in the 1960s. The compound also has been used in waterproof textiles, electrical wire casing and more.
Similar to PFOA, PFOS has been used in the production of everyday household items as well. One of the most well-known products that contained PFOS was 3M’s line of ScotchgardTM stain repellants. PFOS also has been used in pesticides, surface coatings for carpets, furniture, waterproof apparel and paper goods.
PFOA and other PFASs have been used to produce TeflonTM and other fluoropolymers, which coat a wide range of products to protect against heat, chemicals and corrosion. PFASs also have been used in aqueous film forming foam, which was developed in the late 1960s to extinguish petroleum fires.
PFASs, and PFOA and PFOS in particular, have been in the spotlight due to numerous incidents of widespread contamination and mounting toxicological evidence, much of which came from the producers and users of the chemicals themselves. As a result, PFOA and PFOS have been targeted for control and removal by various cities, states and the federal government. While awareness of these substances seems to have gained momentum over the past 20 years, evidence of PFASs’ stubborn persistence and toxicity has been around since the late 1960s and 70s, only to be overlooked until relatively recently. This resulted in delayed intervention, even as the substances continue to be released into the environment.
The manufacture and use of PFOA, PFOS and other similar PFASs have decreased significantly in the United States due to a series of EPA-facilitated voluntary phase- outs by major manufacturers that occurred starting in 2000. Remaining sources of these chemicals may come from existing stocks that might still be in use, from companies not participating in the voluntary phase-out of these chemicals, and the presence of these substances in imported products. While industrial releases of PFOA and related compounds have declined in the United States, along with production in other industrialized nations, China’s production has been increasing, and the country is now the largest emitter of PFOA in the world.
After the phase-out of PFOA and PFOS, manufacturers began replacing them with different, but similar, chemicals, with claims of reduced toxicity and bioaccumulation. However, there are concerns that these alternatives to legacy PFASs may in fact have the same problems as their older relatives. While these chemicals may not be as likely to accumulate in the tissues of people and animals as their predecessors, they are still resistant to breaking down. The emerging PFASs also are less effective, creating concern that they may be used in larger volumes and thus negate any benefits of lower bioaccumulation. Moreover, there is evidence that they can transform into legacy PFASs. Many of these newer chemicals lack important, publicly available data on characteristics such as their chemical properties and toxicity.