Fluoride Action Network


The most comprehensive database for fluorinated pesticides, including the inorganic compounds Cryolite and Sulfuryl Fluoride, as well as hundreds of organo-fluorine compounds that may well prove to be as toxic, or more toxic, than the chlorinated pesticides they are replacing.

Sulfuryl Fluoride

Dow AgroSciences won! The rest of us lost.

The use of sulfuryl fluoride as a food fumigant on post-harvest food was first approved by the US EPA Office of Pesticides in 2004. This decision led EPA to approve the highest levels of fluoride residues on food in its history – see the levels here.  According to EPA, sulfuryl fluoride breaks down rapidly to the fluoride anion in the human body and fluoride is the toxicological endpoint of concern. Its main target is the brain (search Brain here).

FAN became involved in 2001 when Dow AgroSciences first petitioned US EPA for an Experimental Use Permit for sulfuryl fluoride on raisins and walnuts. FAN submitted comments and formal Objections and then in 2004 and 2005 EPA approved its use and high fluoride levels on all processed food, beans, grains, flour -and much more, including a fluoride residue of 900 ppm on dried eggs! FAN collaborated with two great groups, the Environmental Working Group and Beyond Pesticides, and a masterful pro-bono lawyer (Perry E. Wallace, Esq.), to reverse EPA’s approval, through a series of substantive submissions to the US EPA.

Incredibly, after many years of hard work, in January 2011, EPA concluded that it agreed with “all” of our objections (excepting an earlier petition) and published their proposal to phase-out sulfuryl fluoride. According to protocol, EPA simultaneously solicited public comments on the phase-out.  Dow responded with a vengence (see Industry-backed bill seeks to undo phaseout of sulfuryl fluoride). In the end, Dow AgroSciences, the proprietary maker of sulfuryl fluoride, was successful in lobbying the U.S. Congress to stop the phase-out.

The use of the fumigant Sulfuryl fluoride, which EPA knows severely attacks the brain, is now used on America’s post-harvest food.

In January 2014, the Congressional Conference Committee on the Agricultural Act of 2014 released the final compromise language for the legislation, also known as the “Farm Bill.” The committee added the following language at the eleventh hour, that reversed EPA’s proposed phase-out of the neurotoxic fumigant sulfuryl fluoride (which erased 8 years of hard work to achieve). Here’s the trophy that Dow won:

Agricultural Act of 2014 – Sec. 10015 Regulation of sulfuryl fluoride.
Notwithstanding any other provision of law, the Administrator of the Environmental Protection Agency shall exclude non-pesticideal sources of fluoride from any aggregate exposure assessment required under section 408 of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 346a) when assessing tolerances associated with residues from the pesticide.
(Page 806 at http://www.agri-pulse.com/uploaded/Farm-Bill-conference-summary-2014.pdf)

A personal note. FAN’s team (Michael, Ellen, Chris, and Paul) worked thousands of hours on this issue. When I learned that the U.S. Congress gave Dow what it wanted, I felt like I was literally run over by a train. It took me 5 years to write the end on this American tragedy. My apologies to all those who read this article not knowing how it ended. (January 2020, EC)

6 things to know about Sulfuryl Fluoride

1. It is exceptionally toxic and workers who use it are at risk. One 1998 study compared the effects on fumigation workers who used either methyl bromide or sulfuryl fluoride. The study found that sulfuryl fluoride workers suffered “subclinical effects on the central nervous system” as well as observable “cognitive deficits.”

2. In all animals (rats, mice, rabbits, dogs) exposed to sulfuryl fluoride in Dow’s experiments, it was found to create severe and rare effects in the brain. Notably, it harmed the brain white matter and created vacuolation (holes) in several parts of the brain (cerebrum, white matter, thalmus/hypothalmus, etc.). Incredibly, effects on the bone were not studied.

3. We know that when sulfuryl fluoride is used, two different residues are left “in” and/or “on” the food. These residues are “fluoride” and “sulfuryl fluoride.” EPA has given legal tolerances for each. However, we know very little about the chemical “sulfuryl fluoride” itself, aside from the fact that it is severely toxic and its main target is to attack the brain.

4. FAN was told that Dow AgroSciences campaigned hard to get US EPA to accept sulfuryl fluoride as the replacement fumigant for methyl bromide. Because methyl bromide is an ozone destroyer, western countries were obligated under the UN Montreal Agreement to end all uses. Only the US hasn’t complied with this mandate. FAN agrees that all uses of methyl bromide in the US must end immediately, but substituting it with sulfuryl fluoride is unwise for many reasons including the fact that it is a potent greenhouse gas. Of note: Dow is the producer of both fumigants (for structural and food uses)!

5. In response to FAN’s Objections,  US EPA proposed to phase-out the use of sulfuryl fluoride as a food fumigant in 2011 on the basis that children were overexposed to fluoride. The Food Quality and Protection Act (FQPA) states that “aggregate exposure levels of consumers (and major identifiable subgroups of consumers)” must be taken into account. We know that children are overexposed to fluoride because of the incredibly high levels of dental fluorosis reported by the Centers for Disease Control: 41% of children aged 12-15. Because of this and the several other objections we made, US EPA could not justify new sources of exposure. However, Dow AgroSciences and its chorus in industry and Congress, are opposed to any justification for a phase-out.

6. You can avoid exposure to the fluoride residues from the use of sulfuryl fluoride by buying organic or growing your own. America now has a class system for food, and the poor are the ones who will suffer. Note: Most of our organic food is grown with pesticides. However, the organic regulations does not allow the use of the worst pesticides.

FAN Submissions to EPA

EPA Human Health Risk Assessments



Other EPA Comments

Dow’s Submissions


Other Submissions to EPA

Greenhouse Potential

Submission to EPA:

June 10, 2009 –Opposition to the use of sulfuryl fluoride as a soil fumigant,
We oppose issuing this permit. Sulfuryl fluoride is 4,780 times as potent a greenhouse gas as carbon dioxide over a 100 year time horizon…”  From: Sierra Club, Center for Biological Diversity, Pesticide Action Network, Alaska Community Action on Toxics, Center for Environmental Health, Defenders of Wildlife

News articles:

July 2009, Dow Pitching New Pesticide That Doubles As an Extraordinarily Potent Greenhouse Gas, Center for Biological Diversity

March 2009, Sulfuryl fluoride: New greenhouse gas identified, MIT News

January 2009, Termite Insecticide Found To Be Potent Greenhouse GasScience Daily 

Published papers:

Zhao Z, Laine PL, Nicovich JM, Wine PH. 2010. Reactive and nonreactive quenching of O(1D) by the potent greenhouse gases SO2F2, NF3, and SF5CF3. Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6610-5. Full article.
Andersen MP, Blake DR, Rowland FS, Hurley MD, Wallington TJ. 2009. Atmospheric chemistry of sulfuryl fluoride: reaction with OH radicals, Cl atoms and O3, atmospheric lifetime, IR spectrum, and global warming potential. Environ Sci Technol. 2009 Feb 15;43(4):1067-70. Abstract.
Papadimitriou VC, Portmann RW, Fahey DW, Mühle J, Weiss RF, Burkholder JB. 2008. Experimental and theoretical study of the atmospheric chemistry and global warming potential of SO2F2. J Phys Chem A. 2008 Dec 11;112(49):12657-66. Abstract.
back to top