Fluoride Action Network

Changes to Inhalation toxicity values for Sulfuryl Fluoride and Dichlorodifluoromethane

Source: New Jersey Department of Environmental Protection, Division of Air Quality | October 25th, 2017

Revisions to Inhalation Toxicity Values and Risk Screening.

Reference Concentration for Long-Term:
Additions: Sulfuryl fluoride (Cal 06)
• Dichlorodifluoromethane – Changed from 200 ug/m3 (HEAST 97) to 100 ug/m3 (USEPA 14)

*Original online at http://fluoridealert.org/wp-content/uploads/nj.inhalation-risk-changes.sulfuryl-f.cfc12.2017.pdf

Notes from FAN:


from OSHA:

  1. Dichlorodifluoromethane, when at least 99.97% pure, is approved by the FDA as a direct-contact freezing agent for foods (21 CFR 173.355). It is now banned by the EPA, however, due to environmental concerns about stratospheric ozone depletion.
  2. Dichlorodifluoromethane has not been manufactured in the U.S. since 1995, although it was detected at least twice in at least one drinking water source in California during the period, 2002-2004.
  3. EPA’s oral reference dose (daily oral exposure likely to be without an appreciable risk of deleterious effects during a lifetime) of dichlorodifluoromethane is 0.2 mg/kg/day.

from FAN:  Dichlorodifluoromethane, Adverse Effects (apologies, many links may not be working)

6 things to know about this fumigant used on (1) post-harvest food and (2) structures

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.

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 was the producer of both fumigants! It recently sold this fumigant.

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 –CDC reported that 41% of children aged 12-15 were diagnosed with it. 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 sulfuryl fluoride residues by buying organic or growing your own food.