Tennessee has enacted a law that will limit the ability of its state agencies to craft new chemical regulations unless the rules are supported by ‘the best available science’.
The industry-supported bill (SB 880) marks a sharp contrast with dozens of US statehouses that have considered legislation this year to restrict the use of chemicals, especially per- and polyfluoroalkyl substances (PFAS), in various areas.
While Tennessee has not been particularly active in terms of chemicals regulation, the bill could impede future action in the state. The Tennessee Department of Environment & Conservation (TDEC), for example, is currently conducting PFAS testing of state drinking water and working with an interdisciplinary working group to determine a potential future course of action on potential sources of PFAS contamination.
More broadly, passage of the law in a Republican-majority state could serve as a blueprint for industry groups such as the US Chamber of Commerce, which promoted the Tennessee bill, to push for similar legislation in other conservative states.
"It’s a wolf in sheep’s clothing," said Nathaniel Hitt, senior scientist at the NGO West Virginia Rivers Coalition. Dr Hitt, a former fish biologist with the US Geological Survey, was part of a group of scientists that successfully lobbied against a similar ‘sound science in regulations’ bill (HB 2493) that failed to pass in West Virginia’s legislative session this year.
Everyone supports the use of sound science, he told Chemical Watch News & Insight. "But the provisions of the bill, that’s where it counts, and that’s where it’s problematic."
While some of the "most flagrant science-censorship provisions" in the Tennessee bill were removed before final passage, Dr Hill said, the law "is still out of step with standard scientific practice because it creates unnecessary barriers for state agencies to use important public health research".
Defining best available science
Starting 1 July, Tennessee’s law prohibits TDEC or other state agencies from adopting any rule that establishes numeric or criteria limitations for a "contaminant, pollutant, hazardous substance, solid waste or hazardous waste" unless such a rule is based on the best available science.
The law defines ‘best available science’ as that which:
- is reliable, unbiased and reasonably applies to the agency rule;
- maximises the quality, objectivity and integrity of information, including statistical information; and
- involves the use of supporting studies conducted in accordance with generally accepted scientific or technical practices, including studies published in a refereed journal that uses an editorial board or critical review panel and takes meaningful steps to avoid bias.
The final text of the bill removed language that would have barred agencies from using supporting studies that charge publication or submission fees, a common practice among many peer-reviewed journals, including Nature, Environmental Toxicology and Chemistry and Proceedings of the National Academy of Sciences (PNAS).
The law, formally published on 29 April, only applies to rules that would be more stringent than federal standards or where there is an absence of federal regulation.
Direct link to harm
Under the Tennessee law, the underlying science used to justify a state regulation must also establish a direct link to manifest bodily harm in humans. However, the law does allow the use of data from tests performed on animals or animal cells where there is an absence of voluntary scientific studies of humans.
According to Dr Hitt, studies indicating a direct link to harm in humans are hard to come by "because scientists cannot experiment on humans to demonstrate toxicity".
For example, "there are currently no experimentally controlled studies showing that lead exposure causes developmental neurotoxicity", he told West Virginia lawmakers in testimony earlier this year.
Gretchen Salter, policy director at the NGO Safer States, said the measure sets an impractical standard, notwithstanding the caveats.
"It requires the state to prove a chemical causes specific health harms at specific exposure levels if they want to adopt stronger standards than the federal government or act in absence of federal requirements," she said. "This would likely delay or stop meaningful health protections on chemicals like PFAS."
The larger question, according to Salter, is, "Why is a state making it almost impossible to protect the health of its citizens from cancer and other diseases linked to toxic chemicals and letting polluters off the hook?"
Law aimed at emergent chemicals
Attorney Mark Behrens, who spoke to Tennessee lawmakers on behalf of the US Chamber of Commerce when the bill was introduced in February, said that if a state agency is going to set an environmental regulation, "it simply has to be based on the best available science".
He said the legislation is intended for emergent chemicals "where the science is evolving and it’s not clear that they have any effect on human health". These types of emergent substances include PFAS, microplastics and solvents, according to Behrens.
The bill’s sponsor, state Senator Shane Reeves (R), offered similar comments when he introduced the measure.
It is designed to "move away from public policy overreaction to events influencing regulatory actions", Reeves said.
"We need science, not emotions," he continued. The legislation will require regulators to focus on chemical compounds that are more likely to cause harm to human health, Reeves added.
Dr Hitt, however, said the Tennessee law "solves a problem that doesn’t exist".
State agencies are made up of professionals and they have the training to know what is good science and what is junk science, he said. This bill only undercuts their integrity and authority.
Neither the Chamber nor Senator Reeves’ office responded to requests for comment on the legislation.