States can take precautions now on another PFAS chemical.

EPA has issued a toxicity assessment for #PFBS, one of the more than 9,200 #PFAS chemicals known to exist. NH regulates 4 of them in drinking water. Other states like Vermont and Massachusetts have moved to regulate 5 or 6 PFAS chemicals with a total not to exceed 20 parts per trillion for all 6, this could be more stringent than the NH maximum contaminant levels (MCLs).

EPA says that health outcomes evaluated across available studies included effects on the thyroid, reproductive organs and tissues, development, liver, lipids and lipoproteins, and kidneys following oral exposure to PFBS. Based on information across different sexes, lifestages, and durations of exposure, EPA says “the thyroid appears to be particularly sensitive to oral PFBS exposure.” The EPA toxicity assessment concludes that the critical effect dictating the exposure threshold (reference dose) is based on the thyroid based on studies in mice that results in decreased serum thyroxine, T4 ( a thyroid hormone) in neonatal mice.

EPA says that health outcomes evaluated across available studies included effects on the thyroid, reproductive organs and tissues, development, liver, lipids and lipoproteins, and kidneys following oral exposure to PFBS. Based on information across different sexes, lifestages, and durations of exposure, EPA says "the thyroid appears to be particularly sensitive to oral PFBS exposure."

RfDs can be combined with exposure information in risk assessments, and subsequent risk management activities can lead to development of regulatory standards (e.g., Maximum Contaminant Levels) or non-regulatory guideline values (e.g., health advisories) for drinking water under the Safe Drinking Water Act (SDWA), and human health water quality criteria for permitting discharges into ambient waters under the Clean Water Act (CWA)."

This reference dose (RfD) is about an order of magnitude higher than the RfDs for PFOA and PFOS in 2016 (which are too high). NH and other states should have enough information now to create an enforceable drinking water standard (MCL) through rulemaking and take a proactive, precautionary approach, hopefully without legislation forcing them to do it. This is important because while treating for the larger molecule or “long chain” PFAS compounds like PFOA or PFOS, the presence of a multitude of other long and short chain PFAS compounds, especially in areas where aqueous non-film forming foams (AFFF) or industrial sources of pollution (like Saint Gobain Performance Plastics in Merrimack, NH) can “gum up” the granular activated carbon causing it to become less efficient treating these contaminants. The first signal for the need to change out the carbon can be a short chain PFAS compound slipping past the system and ending up in drinking water.

In some cases, the cost to replace the filters on a shorter schedule could result in a much higher cost to maintain the carbon beds.

States must act now while still awaiting federal action on all PFAS chemicals. EPA has not issued an enforceable drinking water standard since 1996. We must take a precautionary approach and act quickly to prevent further exposure and cost to the cities and towns and to public health.

Read EPA's press release by clicking here.