What is PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of chemicals, two of which are known to be toxic to humans. These two chemicals, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are no longer produced in the United States. However, they have recently been a topic of public concern, especially in regard to drinking water contamination.

Other PFAS chemicals are used in consumer products including semiconductors, cellphones, textiles, renewable energy, and medical devices. 

Read on to discover science-based answers to some of the most pressing PFAS questions.


Why did PFAS in drinking water become a concern?

PFAS have been used in consumer products and industries since the 1940s. Regulatory interest in PFAS began in 1999 when the USEPA was notified of new information that showed: 1) the general US population was exposed to at least one PFAS, namely PFOS; 2) PFOS and other PFAS remain in the body for several years; 3) animal toxicology studies showed adverse health outcomes.


What do laboratory animal studies tell us about the toxicity of PFAS?

PFAS represent a relatively large number of compounds with many commercial applications due to their unique surfactant properties. However, only a small subset of these compounds have been studied for their toxicity using laboratory animal studies. Much of what is known about PFAS toxicity is from laboratory animal studies conducted primarily with two PFAS: Perfluorooctanoic acid (PFOA) and perfluorosulfonic acid (PFOS). Additional data are being developed on some substitutes such as perflurobutanoic acid ( PFBS) which seems to have a much shorter half-life in animals after exposure.


Does regulating PFAS represent a meaningful opportunity for health risk reduction?

US Environmental Protection Agency’s drinking water contaminant regulations must meet a qualitative “meaningful opportunity” threshold in health risk reduction. Using our Relative Health Indicator (RHI) metric, we quantify the ranges of potential health risk reductions that could be achieved from state and federal per- and polyfluoroalkyl substances regulatory levels (proposed or finalized) and compare them with previous regulatory determinations of other contaminants to create a quantifiable, comparable scale of “meaningful opportunity” justifications. Our results demonstrate that the regulatory levels for PFOA and PFOS alone will not achieve a national meaningful health risk reduction as compared with previously regulated contaminants.


What are the cost implications of the designation of PFOA and PFOS as hazardous substances under CERCLA?

Designation of PFOA/PFOS as hazardous substances under CERCLA could subject cities to cleanup responsibility and litigation costs for contamination resulting from the operation of landfills and wastewater treatment facilities (POTWs). PFOA/PFOS have been found in the leachate from municipal landfills that can migrate to adjacent properties. Biosolids generated by POTWs may contain PFOA/PFOS which can contaminate agricultural lands on which it is applied.


What are safe exposure limits for PFAS in drinking water and why the wide range of MCLs?

A Maximum Contaminant Level (MCL) is the amount of a substance that is allowed in public drinking water. Federal Maximum Contaminant Levels are produced by EPA. The EPA has not developed a MCL for any PFAS, but it did publish Health Advisories of 70 ppt for PFOS and PFOA in 2016. These are guidance values and are not federally enforceable or require monitoring of public water systems, however, they have been adopted by many states. Other states have developed their own standard or guidelines. 



What do human studies tell us about the toxicity of PFAS?

Despite hundreds of studies that have been published, the science on PFAS human health risk is full of uncertainties and inconsistent interpretations by scientists, even for the most wellstudied PFAS – PFOS and PFOA. Not all scientists agree on the potential health effects related to PFOS or PFOA in drinking water. It is generally agreed that there may be an association between exposure to PFOA and kidney and testicular cancer. PFOS and PFOA may be associated with increased cholesterol levels, decreased vaccine response for some vaccines in children, and kidney disease. Additional research may change our understanding of the relationship between PFAS exposure and human health effects.


What are the costs associated with PFAS regulations?

The American Water Works Association wrote in a public comment to the EPA that the national burden of drinking water treatment for PFOA and PFOS is upwards of $50 billion over the next two decades.

According to the U.S. Chamber of Commerce, annual costs for regulating PFAS under CERCLA are “conservatively” estimated between $700 and $800 million which exceeds the threshold of more $100 million required for a full regulatory impact and cost-benefit analysis. Some states, like Maine, estimate that the lab-approved PFAS tests will cost around $400 to $500 per test. 

PFAS Resources

Our country has achieved broad successes in the delivery of safe, clean water in support of public health. Here are some resources from trusted organizations that can be used to support science-based decision making regarding safe, reliable drinking water for all.

Center For Disease

The Interstate Technology and Regulatory Council (ITRC) is a state-led coalition working to reduce barriers to the use of innovative air, water, waste, and remediation environmental technologies and processes. 


The Environmental Protection Agency is an independent executive agency of the U.S.  federal government tasked with environmental protection matters. 

Center For Disease

The Centers for Disease Control and Prevention is the national public health agency of the United States.

American Water Works Association is an international non-profit, scientific and educational association founded to improve water quality and supply.


The Agency for Toxic Substances and Disease Registry is a federal public health agency within the United States Department of Health and Human Services.

The Association of State Drinking Water Administrators (ASDWA) is the professional Association serving state drinking water programs.

Water & Health Advisory Council Statement on PFAS

Our nation’s water systems have limited resources, funding, and operational capacity. As such, a national standard must be fully substantiated by toxicity and occurrence data before water systems are required to direct more funding and resources towards PFOS/PFOA monitoring. We urge lawmakers to consider a science-based approach to the regulation of PFOA and PFOS which include:

  1. More Robust Occurrence Data: More occurrence data is needed to determine where high-concentration areas of PFOS/PFOA exist nationally. There are regions in the U.S. that face high PFOS/PFOA concentrations and those communities require immediate action and response.  However, regulating on a national level must be based on accurate and current national occurrence data. A one-size-fits-all approach will require water systems to regularly monitor, test and invest millions of dollars and staffing to address contaminants that may not be impacting their community. 
  1. More Substantial Epidemiological and Toxicity Data: Based on the current epidemiological and toxicological data available, regulating PFOA and PFOS does not represent a meaningful opportunity for health risk reduction as defined by previously regulated contaminants. The Meaningful Opportunity for Health Risk Reduction is an essential mandate of the Safe Drinking Water Act, and we believe it must be considered policymakers deliberate on this proposed rule.

A Careful Assessment of Cost and Impact: A handful of known risks present the greatest threats to our drinking water systems, and we must prioritize funding to the areas of highest need. Some communities require swift remedial action to address unacceptable levels of PFOA and PFOS in their drinking water supply, while many others do not. As you evaluate a national standard, we ask that you consider how this will impact local water systems that do not have a threat of these substances in their systems. We have great concern that such national standards will shift funding priorities away from known threats impacting public health, such as failing and aging water infrastructure and protections against microbial contaminants. 

The Safe Drinking Water Act calls on our nation’s leaders to take effective steps towards ensuring a safe, affordable, and reliable drinking water supply for everyone. We ask that policymakers continue to apply a science-based, risk- and cost-benefit analysis when approaching regulating PFOA / PFOS.


Water & Health Advisory Council
Rob Renner, Council Chair, Former Chief Executive Officer at Water Research Foundation
Chad Seidel, Ph.D., President, Corona Environmental Consulting
Joseph Cotruvo, Ph.D., BCES President, Joseph Cotruvo & Associates
Joyce Dinglasan-Panlilio, Ph.D., Division Chair/Associate Professor in Environmental Chemistry at University of Washington-Tacoma
Kathryn Sorensen, Director of Research at the Kyl Center for Water Policy, Arizona State University
Manny Teodoro, Associate Professor of Public Affairs at University of Wisconsin-Madison
Janet Anderson, Principal Toxicologist at GSI Environmental Inc.

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