ACC is strongly concerned with EPA’s draft Integrated Risk Information System (IRIS) assessment for hexavalent chromium. As we have told EPA, the draft assessment is not based on the best available science and is inconsistent with respected international authorities.
But we are not alone in our concerns. In fact, several organizations around the country have written to EPA that the draft assessment minimizes the importance of the most recent high-quality research, and any future regulatory action could have little to no measurable public health benefit.
Here’s what they are saying:
National Agencies and Organizations
U.S. Chamber of Commerce: “EPA’s draft conclusions do not appear to be scientifically supportable. EPA’s analysis appears to minimize the importance of the most recent high-quality research. It concludes that there is essentially no safe level for certain exposures to Cr(VI) despite the overwhelming scientific evidence contradicting this conclusion and the conclusions of other authoritative bodies. This disparity calls into serious question whether EPA’s analysis is scientifically supportable.”
American Water Works Association (AWWA): “AWWA is particularly concerned that the final toxicological review meets the needs of EPA’s Office of Water. As currently drafted, the toxicological review implies a health concern for a concentration of Cr(VI) in water that is almost 3,000 times lower than the current total chromium maximum contaminant level and does so largely based on a single pair of animal studies where the lowest doses tested were nearly 300,000 times higher than the alleged level of concern in humans exposed via drinking water ingestion. AWWA has previously commented to EPA that a fit-for-purpose analysis was necessary.”
National Association for Surface Finishing (NASF): “NASF is concerned that the agency has produced a faulty draft human health assessment, with potentially far-reaching consequences for future risk management decisions, including federal drinking water and other EPA standards and regulations. NASF urges both EPA and the recently formed Science Advisory Board Hexavalent Chromium Review Panel to consider the comments below to appropriately address pertinent science concerns, consider the conclusions of other authoritative bodies worldwide and minimize the likely onerous yet unnecessary impacts the draft IRIS assessment could have on surface finishing industry and other industry sectors in the future.”
Coachella Valley Water District (CVWD): “CVWD has reviewed the subject assessment and believe it does not reflect the findings of numerous peer reviewed studies, including those listed in the enclosure, that were completed following the 2008 National Toxicology Program (NTP) rodent study EPA has used to support the draft conclusions in the subject assessment. These more recent studies clearly support a cytotoxic mode of action (MOA) for Cr(VI) ingested by the rodents used in the NTP study rather than the EPA assumed mutagenic MOA. As such, these studies clearly support a threshold dose response rather than the assumed default linear dose response for Cr(VI) used in the assessment. These incorrect assumptions result in a presumed Cr(VI) ingestion risk, as illustrated by the estimated oral cancer slope factor included in the subject assessment, that is orders of magnitude greater than what is supported using the more recent toxicological studies.”
Specialty Steel Industry of North America: “EPA’s inconsistent conclusions are driven by the agency’s failure to contend meaningfully with the results of the most recent state-of-the-art science on Cr6 carcinogenicity and, instead, relying on default “linear no-threshold” assumptions that, in the case of hexavalent chromium, are demonstrably incorrect. This flawed approach will have adverse real world consequences as EPA and other regulatory bodies use the IRIS assessment as the basis for future federal and state actions. In addition, a flawed IRIS evaluation will lead to flawed risk assessments and other toxicological evaluations or classifications of products that contain or may result in exposure to hexavalent chromium. SSINA is particularly concerned that EPA’s flawed evaluation of Cr6 will spill over to regulations intended to address other forms of chromium or products containing chromium.”
Leather & Hide Council of America (LHCA): “LHCA fully supports and encourages scientifically-based regulation of hexavalent chromium, and urges EPA to complete the current IRIS assessment after considering all relevant information, including results from critical carcinogenic mode of action research that demonstrate a biological threshold for hexavalent chromium toxicity. Unfortunately, the draft IRIS assessment largely dismisses the importance of this research, which significantly undermines the credibility of EPA’s evaluation.”
In addition, national and international public health and regulatory agencies have set drinking water guidelines and standards to protect the public from all forms of hexavalent chromium in drinking water. Here’s what they have said:
In 2020, the World Health Organization (WHO) issued a final background document that recommends retaining the current WHO guideline value for total chromium – 50 parts per billion – based on “the newer, high-quality data from chronic drinking water carcinogenicity studies.”
In 2019, the Food Safety Commission of Japan concluded that a threshold could be established for chromium in drinking water, and that currently available science would support a safe level in drinking water in the range of 30-60 parts per billion.
In 2018, Health Canada issued a final maximum acceptable concentration of 50 parts per billion for total chromium, finding the weight of evidence, including review of the large body of peer-reviewed published mode of action (MOA) studies, supports a non-mutagenic, threshold MOA for intestinal tumors.
