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INSIDE EPA
Tuesday 18 July 2006

Activists Target Fluoride Pesticides To Tighten Drinking Water Limits
By Trevor Knoblich

Environmentalists are poised to challenge EPA’s decision to license a fluoride-based soil fumigant pesticide, which they say could draw attention to the broader issue of whether fluoride standards for drinking water adequately protect public health.

EPA July 5 opened public comment on a petition from three environmental organizations calling on the agency to temporarily ban the use of the pesticide sulfuryl fluoride, a soil fumigant. Environmentalists are seeking the ban until the agency addresses their previous calls for an administrative hearing on EPA’s decision to register, or license, certain uses of the chemical.

EPA registered the chemical in 2005 for uses in food processing facilities, bakeries, rail cars and other storage areas. EPA and industry sources say the product serves as an alternative for similar uses of methyl bromide, a pesticide which faces phaseout under an international treaty because it is thought to deplete stratospheric ozone.

But Environmental Working Group (EWG), Fluoride Action Network (FAN) and Beyond Pesticides charge that allowing any use of the pesticide will increase fluoride-related human health risks. They argue EPA’s decision did not meet statutory requirements in the 1996 Food Quality Protection Act (FQPA) amendments to the Federal Food, Drug & Cosmetic Act (FFDCA), and threaten legal action if EPA does not open a public hearing on sulfuryl fluoride safety limits, known as tolerances.

The law firm Zelle, Hofmann, Voelbel, Mason & Gette filed an administrative petition with EPA June 1, asking the agency to ban use of sulfuryl fluoride pending a public hearing on its decision to register the chemical. The petition states that EPA did not follow statutory requirements to perform a thorough assessment of exposures and risks associated with the pesticide. For example, the petition states that EPA inappropriately used the Office of Water’s Maximum Contaminant Level Goal (MCLG) as the basis for its risk assessment for sulfuryl flouride.

The MCLG is used to set an enforceable exposure drinking water standard, or maximum contaminant level (MCL). Both the MCLG and MCL are currently set at 4 parts per million.

Under FQPA, the agency is required to consider “aggregate exposure,” or exposure through different mediums, of potentially toxic chemicals. The environmentalists argue that EPA did not appropriately consider fluoride exposure through drinking water, relying on a faulty water standard for its risk assessment for sulfuryl fluoride.

The petition also states that EPA did not meet FQPA requirements to fully protect children’s health. They argue the agency’s children’s exposure estimates were too conservative, and that the agency should consider severe dental fluorosis to be an adverse health effect under FFDCA.

“In failing to take into account the special vulnerabilities of infants and children, as expressly required in FFCA Section 408(b)(2)(C), EPA has acted in violation of law and thus there is a substantial likelihood that objectors will succeed on the merits of this matter,” the petition says.

The petition calls on EPA to stay its tolerance decisions until the agency responds to the environmentalists’ concerns. Relevant documents are available on InsideEPA.com.

“As a result of these broad-reaching, staggeringly high fluoride tolerances, EPA’s own data shows that sulfuryl fluoride will become the second largest daily source of fluoride in the U.S.,” the petition states. “The tolerances, therefore, represent a major new source of fluoride exposure in the U.S. and will -- in conjunction with all other sources of fluoride to which Americans are exposed -- contribute to millions of Americans exceeding EPA’s purported safe dose.”

Both EPA and Dow AgroSciences, the company that manufactures sulfuryl fluoride, say the agency underwent an extremely detailed risk assessment, and argue that the exposures resulting from sulfuryl fluoride use are well below EPA’s reference dose (RfD), or level at which long-term pesticide exposure is considered “safe.”

“When all quantified dietary and non-dietary exposure pathways are combined, risk estimates range from 17 to 43 [percent] of the RfD. These aggregate risk estimates are below [the Health Effect Division’s] level of concern for all population subgroups,” according to EPA’s 2004 risk assessment.

But environmentalists say their argument is supported by a March report from the National Academy of Sciences (NAS), which calls on EPA to revise and tighten its MCLG for naturally occurring fluoride in drinking water. The NAS report highlights concerns that long-term exposure to fluoride could result in bone fractures or other bone diseases. NAS did not recommend a new MCLG, instead asking EPA to perform its own analysis to establish a more stringent value.

Environmentalists hope the pesticide issue could influence EPA’s approach to an MCL, which they argue is based on out-of-date science. For example, if their petition results in a more detailed fluoride risk assessment, it could further articulate the need for a more stringent MCL. Environmentalists could then push for the more stringent standard, as called for in the NAS report.

One environmentalist says if EPA denies the petition or the public hearing, a lawsuit is imminent. “We’re in this all the way to the finish line,” the source says. “We do not think these tolerances are justifiable, and they pose significant risks to children’s health.”

Another environmental source says if EPA denies the petition to temporarily ban the chemical, the groups would ask a federal court to overturn the agency’s decision.

An industry source says EPA performed a thorough assessment and did not find any additional risks associated with the sulfuryl fluoride. The source also points out the value of the chemical as a potential methyl bromide substitute.

EPA states in a July 5 Federal Register notice that it is seeking public comment on the petition due to the complex science and policy issues surrounding the chemical. “Given that the tolerances as to which the stay is being sought have been in effect for an extended period and that the request for a stay raises complex science issues of great public interest, EPA is . . . requesting comment on the motion,” the document states.

The industry source says groups are preparing public comments on the issue, which are likely aimed at discrediting the environmentalists’ reliance on the NAS report. “The report doesn’t in itself have any effect on sulfuryl flouride tolerances,” the source says.

One EPA source says the agency is seeking public comment on the petition because “our decision will affect people no matter which way we go.” The agency wants to give all parties a chance to comment. The source also notes that limiting sulfuryl fluoride use would likely hamper agency efforts to limit the uses of methyl bromide.

Public comments on the chemical close August 4. A second EPA source says the agency will likely issue a decision on the move to ban the tolerances shortly after the deadline, after the agency reviews the comments.

EPA has also said it is taking NAS’s recommendations into account, and any changes in drinking water limits would include detail from the report.

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