A short time ago we discussed some of the dangers of PFAS (Per- and Polyfluoroalkyl Substances), which are sometimes called Forever Chemicals. To recap: thousands of these chemicals have been a common part of our lives since the 1940s. They’re actually somewhat difficult to avoid as they’re present in an extremely long list of consumer, commercial and industrial products, from mattresses to cosmetics and cookware…and everything in between. They’ve been found in all corners of the globe, including the remote Arctic. But perhaps most worryingly, they’ve been appearing in our drinking water, and ergo, our bodies, accumulating and causing long term and serious health impacts.
The chemicals are resistant to heat, water and oil – giving them a huge appeal for the above uses. But they are also resistant to degradation in our natural environment – meaning they are simply moved from place to place while still intact and causing damage.
So it was an enormous relief when the EPA announced a proposed ruling to regulate the presence of the chemical in the drinking water. Although several states already limit the presence of PFAS in water (Maine, New Hampshire, Vermont, Massachusetts, Pennsylvania, Michigan, New York, Rhode Island and New Jersey), there hasn’t been a federal mandate. This proposed law is called the National Primary Drinking Water Regulation (NPDWR) and would apply legally enforceable levels of 6 of these PFAS. Although a proposal at this stage, the EPA expect it to come into force by the end of 2023. The outcome is anticipated to be the prevention of thousands of deaths and tens of thousands of PFAS related illnesses.
The 6 PFAS which will have this Maximum Contaminant Level (MCL) applied, are: PFOA and PFOS as individual contaminants; and PFHxS, PFNA, PFBS, and HFPO-DA (commonly referred to as GenX Chemicals) as a PFAS mixture. Beyond the chemistry itself, what will this mean? Industry giants, like 3M, DuPont and Chemours, could see a flurry of lawsuits directed their way, as the PFAS polluters, in answer to Municipalities needing to remove the chemicals from their drinking water supply. This, of course, throws up the question of how exactly the compounds can be removed?
There’s no easy solution. Each PFAS molecule has a head, which is hydrophilic, and a long tail, which is hydrophobic and contains carbon-fluorine bonds. This is one of the strongest single bonds found in nature, and hence leads to the ‘forever’ tag. Even when PFOS and PFOA are broken down, they for smaller-chain fluorinated molecules which are still harmful. PFOA and PFOS are two of the most common PFAS and have long been the focus of water treatment efforts.
Some methods which have been used for some time now are reverse osmosis, ion-exchange resins, and granulated activated carbon. These are far from 100% effective, costly, and create a concentrated waste stream. Managing the waste is as much a concern as the initial removal. Currently, the only truly effective technique to deal with the molecules, once removed from the water supply, is to incinerate the materials which the PFAS is stuck to. Obviously this is far from ideal, as it comes with a slew of other serious concerns. So much more work in this space is required, fast.
It is thought that PFAS chemicals are within the drinking water of up to 200 million Americans. And up until this new regulation, the advice from the EPA was to limit below 70 parts per trillion (ppt) of PFOS and PFOA. However, science has shown that this was still unacceptably high. Exposure to anything higher than 0.02ppt is dangerous. So in 2022 the EPA set ‘advisory health limits’ of 0.02ppt and 0.004ppt for PFOA and PFOS respectively. What will the new regulation say? 4ppt for each.
Is that a safe level? No.
But is it better than 70ppt? Yes!
Although these new rules have been labeled “groundbreaking”, the fact that the regulation applies to only 6 of around 14,000 PFAS should also be kept in mind. So we will gratefully accept this step in the right direction, while acknowledging that more must be done – ideally in the near future.
