On March 14th, the Environmental Protection Agency (EPA) announced a proposal to regulate six per- and polyfluoroalkyl substances (PFAS) compounds in drinking water. This proposal is significant because it would mark the first time that the EPA has established a maximum contaminant level (MCL) for PFAS compounds in drinking water. The six compounds included in the proposal are: perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA). Given the fact that there are thousands of individual PFAs in existence, regulating just six might not seem like a big deal. But PFAS compounds commonly co-occur with each other, so regulating these six would remove many more in practice.
The EPA’s proposal will set MCLs at 4.0 parts per trillion (ppt) for PFOA and PFOS, with the limits of HFPO-DA (also called GenX chemicals), PFBS, PFNA, and PFHxS to be determined by a “hazard index” of their combined relative concentrations. These limits may potentially change in response to public comments. These levels are higher than the current health advisory levels for PFOA and PFOS, which are set at 0.004 ppt and 0.02 ppt, respectively. However, the EPA is also proposing new “health-based, non-enforceable Maximum Contaminant Level Goals (MCLGs)” for these six PFAS chemicals, which may be more stringent. The proposal also includes requirements for public water systems to monitor for PFAS compounds and report their results to the EPA. This will help to identify areas where PFAS contamination is a problem and enable the EPA to take action to address it.
So what are PFAS compounds, and why are they a concern? CleanAir has written several news blogs regarding PFAS on our website. To summarize, PFAS compounds are a group of synthetic chemicals that have been widely used in industrial and consumer products for decades. They are resistant to heat, water, and oil, making them useful for a variety of applications, such as non-stick cookware, waterproof clothing, and firefighting foam; they have even been found in cosmetic products. However, PFAS compounds have also been linked to a range of health problems, including cancer, liver damage, birth defects, and immune system dysfunction. They are known as “forever chemicals” because they take thousands of years to break down in the environment, and they tend to accumulate in the human body over time.
So, how long have we known about the risks associated with PFAS compounds? The answer is: for a while. The first studies linking PFAS compounds to health problems were conducted in the 1970s, and by the late 1990s, researchers were raising concerns to the EPA about their persistence in the environment. Despite this knowledge, PFAS emissions were not regulated in the United States until relatively recently. In 2016, the EPA established their first non-binding health advisory level for two types of PFAS compounds, PFOA and PFOS, in drinking water. This health advisory level was set at 70 ppt for the combined concentration of PFOA and PFOS.
However, this health advisory level was criticized by many as being too high, and there was increasing pressure on the EPA to establish an enforceable MCL for PFAS compounds in drinking water. The new proposal to regulate six PFAS compounds in drinking water represents a step towards addressing this issue.
But what about PFAS compounds in the air? Currently, there are no federal regulations for PFAS emissions into the air, although some states have taken action to regulate these emissions. For example, in 2021, New Hampshire passed a bill allowing their environmental services to regulate PFAS emissions from municipal waste incinerators.
The lack of federal regulations for PFAS emissions into the air is concerning because PFAS compounds can be released into the air during manufacturing processes, waste incineration, and other industrial activities. This means that communities near these sources may be exposed to higher levels of PFAS compounds than the general population. In the future, it is likely that there will be increasing attention on PFAS compounds in the air, and pressure on the EPA to establish regulations for PFAS emissions. This may include establishing emission limits for industrial facilities that release PFAS compounds into the air and requiring the use of alternative, less hazardous chemicals in manufacturing processes. The E.U., for example, has already set limits for PFAS chemicals in drinking water and banned the use of PFAS compounds in non-stick cookware.
The EPA’s drinking water proposal represents an important step towards addressing the health risks associated with these chemicals. However, there is still much work to be done to regulate PFAS compounds in the air and to address contamination that has already occurred. The E.U.’s more aggressive approach to regulating PFAS compounds may serve as a model for future regulations in the United States, and there is a growing recognition of the need to apply precautionary principles in environmental policy. Like the chemicals themselves, concern about PFAS compounds does not appear to be going away any time soon; thus, it will be important to continue developing innovative ways to monitor PFAS in our water and air.
If you are interested in putting in your “two cents” about the EPA’s proposal, they will be holding a virtual public hearing on May 4, 2023 where members of the public will be able to comment on the proposal. The EPA states that both oral and written comments will be considered equally in the drafting of the final regulation.