Fluoride Action Network

Dow’s Bait and Switch on Sulfuryl Fluoride

Source: International Fluoride Information Network | March 17th, 2002

Dear All,

A few months ago, on October 4, 2002, we sent out an IFIN bulletin requesting our readers support in fighting a proposal by DOW to get an experimental use permit (EUP) for use of the fumigant sulfuryl fluoride on two food items; walnuts and raisins. The prposed new uise for this fumigant was prompted by the phasing out of methyl bromide, the most commonly used fumigant on foodstuffs, because it is a potent greenhouse gas. There are two problems with using sulfuryl fluoride for this purpose, 1) it is acutely toxic and could pose problems for fumigators and those who live near the warehouses where the fumigant may be used and 2) it is rapidly converted to free fluoride ion. It is the latter fact that most concerned us, because this use of sulfuryl fluoride will introduce a brand new source of fluoride into our lives. Dow was seeking fluoride tolerances for walnuts and raisins but the permit was for just a few years only – it was an experimental use permit (EUP).

About 80 of our readers – at very short notice – sent in comments. On February 5, 2002, the US EPA – ignoring all the recent scientific findings we had raised on health effects -granted DOW its EUP on walnuts and raisins. We will be appealing this decision. More about that later.

Meanwhile, DOW has played the classic bait and switch technique. Having got its EUP for walnuts and raisins, just TEN DAYS LATER on February 15, it sought more fluoride tolerances for the use of sulfuryl fluoride on FORTY MORE food items, and this time it is not asking for an experimental use permit but for permanent set of tolerances for this purpose. So that was a pretty short experiment wasn’t it? This will greatly increase the number of foodstuffs which will LEGALLY have fluoride residues on them

Once again, time is short. Comments have to be into the US EPA by 5.00 pm tomorrow (Monday March 18). Ellen and I are preparing an extensive list of comments. What we hope some of our readers can do is to send in some simple comments to the effect that:

1) The US EPA should be paying more attention to the Public interest not DOW’s interest.
2) That there must be fumigants other than those that contribute to Greenhouse Warming and those that contribute to an unacceptable body burden of fluoride for our population.
3) That there is plenty of evidence ( e.g. the level of dental fluorosis, which affects at least 1 in 3 of our children on at least two teeth, Heller et al, 1997) that our kids are already getting too much fluoride -they don’t need any more.
4) DOW is wrong when they say that fluoride is not an endocrine disrupter (cite pineal gland, thyroid gland, and G-protein interference).
5)DOW is wrong when they say that there are no health effects below a dose of 16 mg of fluoride per day.
6) The US EPA needs to do its homework on this before it allows the chemical industry to walk all over it.
7) The USEPA should consult with its union members who have spoken up against water fluoridation.

Please send your comments by email to this address opp-docket@epa.gov and put the following “docket control number PF-1068″ into the SUBJECT LINE of your email.

The DOW submission can be viewed in its entirety at http://www.fluoridealert.org/pesticides/Sulfuryl.F.FR.Feb.15.2002.htm

Key excerpts are printed below.

Many thanks,

Paul Connett.

PART OF DOW’S SUBMISSION as it appeared in the Federal Register.

DowAgroSciences LLC

PP 1F6312

EPA has received a pesticide petition (1F6312) from DowAgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268 proposing, pursuant to section 408(d) of the FFDCA, 21 U.S.C. 346a(d), to amend 40 CFR part 180 by establishing a tolerance for residues of:

1. Fluoride in or on the following raw agricultural commodities: Date at 5 parts per million (ppm), fig at 5 ppm, plum, prune, dried at 5 ppm, grape, raisin at 5 ppm, fruit, dried at 5 ppm, almond at 10 ppm, pecan at 23 ppm, pistachio at 18 ppm, walnut at 30 ppm, beechnut; butternut; cashew; chestnut; chinquapin; filbert; nut, brazil; nut, hickory; and nut, macadamia at 30 ppm, barley, grain at 10 ppm, corn, field, grain; and corn, pop, grain at 7 ppm, oat, grain at 17 ppm, rice, grain at 10 ppm, wheat, grain at 25 ppm, millet, grain; rice, wild, grain; sorghum, grain; and triticale, grain at 25 ppm and on the processed products corn, field, flour at 26 ppm, corn, field, grits at 10 ppm, corn, field, meal at 28 ppm, corn, field, oil at 3 ppm, rice, brown at 14 ppm, rice, polished rice at 18 ppm, rice, bran at 31 ppm, rice, hulls at 35 ppm, wheat, bran at 40 ppm, wheat, flour at 10 ppm, wheat, germ at 98 ppm, wheat milled by products at 35 ppm, wheat, shorts at 38 ppm, corn, field, refined oil at 3 ppm.

B. Toxicological Profile

1. Acute toxicity. The acute LC50 for sulfuryl fluoride is 642 ppm (1,088 milligram/kilogram body weight (mg/kg/bwt) for CD-1 mice exposed for 4 hours.

2. Genotoxicty. Genetic toxicity did not occur when sulfuryl fluoride was tested in multiple in vivo and in vitro tests.

3. Reproductive and developmental toxicity. Sulfuryl fluoride did not have any effects on reproductive parameters at dose levels that induced treatment-related effects in parental rats and rabbits. In addition, a teratogenic potential for sulfuryl fluoride was not demonstrated in either rats or rabbits at dose levels that induced maternal toxicity.

4. Subchronic toxicity. Several 2-week repeated dose inhalation studies indicate for mice a no observed adverse effect level (NOAEL) of 30 ppm for rat, rabbit, and Beagle dog a NOAEL of 100 ppm.

5. Chronic toxicity. The lowest reported chronic NOAEL for sulfuryl fluoride is 5 ppm based on a 2-year inhalation study with Fischer 344 rats and the parental NOAEL in a 2-generation rat reproduction study. There was no evidence of carcinogenicity in 2-year rat and 18-month mouse studies.

6. Animal metabolism. Rats fed a diet that had been fumigated by sulfuryl fluoride at a rate of 2 lb/1,000 cubic/feet (cu/ft) (containing fluoride levels of 19 ppm above the control level of 36 ppm) for 66 days experienced an increase in the fluoride content of their bones. The National Research Council in their 1993 report on fluoride concluded that fluoride is readily absorbed by the gut and rapidly becomes associated with teeth and bones. The remaining fluoride is eliminated almost exclusively by the kidneys with the rate of renal clearance related directly to urinary pH.

7. Metabolite toxicology. Clinical symptoms of acute fluoride poisoning in humans are characterized by nausea, vomiting, diarrhea, abdominal pain, and paresthesia. The frequently cited “probably toxic dose,” the dose which should trigger therapeutic intervention and hospitalization, is 5 mg/kg/bwt calculated for the lowest third percentile of the infant population. Five to 10 grams of sodium fluoride is considered the certainly lethal dose (CLD) for a 70 kg adult (32 to 64 mg fluoride per kg bwt). One-quarter of the CLD can be ingested without producing serious acute toxicity and is known as the safely tolerated dose, i.e., 8 to 16 mg of fluoride per kg of body weight. The Council on Dental Therapeutics of the American Dental Association recommends that “no more than 264 mg of NaF (120 mg F) be dispensed at any one time” in dental treatments to prevent the accidental poisoning of an infant weighing as little as 10 kilograms. EPA (cryolite RED decision, August 1996) determined a maximum concentration limit goal (MCLG) of 0.114 mg/kg/day for fluoride which provides protection from any known or anticipated adverse health effects. The MCLG has been reviewed and supported by the surgeon general. The National Toxicology Program (NTP) has concluded that there was “no evidence” of carcinogenic activity in male or female mice administered sodium fluoride in drinkingwater for 2 years.

8. Endocrine disruption. There is no evidence from any studies to suggest that sulfuryl fluoride or fluoride are endocrine disrupters.

C. Aggregate Exposure

1. Dietary exposure. The Dietary Exposure Evaluation Model (DEEM), version 7.73, of Novigen Sciences, Inc. was used to estimate the dietary exposure to the U.S. population and critical sub-populations resulting from the use of sulfuryl fluoride under the conditions proposed. The highest potential chronic exposures to sulfuryl fluoride was to children ages 1 to 6 years resulting from the consumption of treated commodities totaling 0.000106 mg/kg/bwt/day. Likewise, the highest potential chronic exposure to fluoride was to children ages 1 to 6 years with a highest estimated exposure of 0.002419 mg/kg/bwt/day.

i. Food. Food tolerances as inorganic fluorine compounds exist to support the uses of cryolite (insecticide) on various food and feed commodities in the U.S. EPA, in the 1996 cryolite RED document, conservatively estimates that the “high-end” dietary exposures to fluoride due to all sources and routes (including the fluorination of water and the potential for fluoride residues resulting from the uses of cryolite) are approximately 0.085 mg/kg/bwt/day. No toxicological endpoint attributable to a single exposure was identified in the available toxicology studies on sulfuryl fluoride or inorganic fluoride that would be applicable for an acute dietary exposure.

ii. Drinking water. There is no anticipated exposure of sulfuryl fluoride to drinking water. As a public health tool to aid in the prevention of dental caries, fluoride is added to some domestic water supplies at generally 0.8 ppm to 1.0 ppm.

2. Non-dietary exposure. Sulfuryl fluoride (as Vikane specialty gas fumigant) is presently used to fumigate homes and other structures to control wood infesting insects. The existing Vikane use patterns and exposed populations are not expected to overlap with the intended post- harvest uses of ProFume.

D. Cumulative Effects

The primary degradation product of sulfuryl fluoride is fluoride. The toxicity of fluoride in various forms has been extensively reviewed and is used as an additive in treated water supplies, toothpastes, mouth rinses, and other treatments for the prevention of dental caries. It is also prescribed in therapeutic amounts for the treatment of osteoporosis. Fluoride is naturally present in both food and water in varying amounts, and has been added to public water supplies to fight dental caries. The recommended concentration of fluoride (usually as fluorosilicic acid) in treated water supplies is 0.8 ppm to 1.0 ppm. The third report on nutrition monitoring in the United States says that food contributes only small amounts of fluoride and monitoring the diet for fluoride intake is not very useful for current public health concerns. The sub-population most susceptible to fluoride is children. For this reason a number of studies have attempted to quantify the fluoride intake from a variety of sources. The total daily intake of fluoride from water (used to prepare formula, juices, and other foods) for infants ages birth to 9 months ranged to 1.73 mg with means from 0.29 to 0.38 mg. Assuming a body weight of 10 kg, these amounts are equivalent to 0.03 to 0.04 mg/kg/day. These levels of dietary exposure in combination with the potential dietary exposures that the proposed uses of ProFume would represent (chronic dietary exposures of 0.002419 mg/kg/bwt/day) are considerably lower than EPA’s MCLG for fluoride of 0.114 mg/kg/bwt/day.

E. Safety Determination

1. U.S. population. Aggregate risk from exposure to sulfuryl fluoride would be minimal because of its rapid dissipation from any fumigated commodity and because it is not expected to be present at the time of food consumption. The sulfuryl fluoride residues in fumigated foods are expected to be non-detectable at the point of food consumption. Furthermore, if residues were considered as high as what is found immediately following the 24-hour aeration period, the margin of exposure to the most sensitive population (children) is estimated to be greater than 80,000 for chronic exposures. Exposure to fluoride, the residue of interest for sulfuryl fluoride, can occur from foods, water, and dental treatments. The additional fluoride residues in some commodities fumigated with sulfuryl fluoride are indistinguishable from the natural levels of fluoride already present and would therefore also fall within EPA’s threshold of regulation policy. Alternatively, fluoride in other commodities are expected to contribute to the fluoride that is ingested, but at levels far below other sources, especially treated water and dentrifices. Chronic exposure to fluoride resulting from the proposed uses of ProFume (0.002419 mg/kg/day) is much lower than EPA’s MCLG of 0.114 mg/kg/bwt/day calculated for exposure to fluorinated water. In addition, there is no directly applicable scientific documentation of adverse medical effects at levels of fluorine below 0.23 mg/kg/day.

2. Infants and children. Chronic exposure to fluoride from the consumption of ProFume treated commodities would be approximately 0.002419 mg/kg/day for a child age 1 to 6 years. This value is much lower than EPA’s MCLG of 0.114 mg/kg/bwt/day calculated for exposure to fluorinated water.

F. International Tolerances

There is no Codex maximum residue level established for residues of fluoride on any food or feed crop.

[FR Doc. 02-3661 Filed 2-14-02; 8:45 am]