The risk of acute fluoride toxicity is not the only reason the EPA should reject the claim in some comments that the tolerances are a de minimis source of fluoride. For example, in considering Dow’s current contention that sulfuryl fluoride can be safely added to our nation’s food supply in small amounts, it is worth noting Dow’s previous statements on this subject. In 1963, Dow stated that:
“Under no conditions should sulphuryl fluoride be used on raw agricultural food commodities, or on foods, feeds or medicinals destined for human or animal consumption.” (Bond 1984) (emphasis added).
It is also worth noting that this remains the clear prevailing view of nearly all western, industrialized countries, even those that have approved the use of sulfuryl fluoride as a fumigant in food processing facilities. As summarized by Dow scientists in 2010:
“ProFume is currently approved on emptied flour mills and emptied silos in the following European countries: Austria, Belgium, Germany, France, Greece, Italy, Ireland, Switzerland and UK . . . .”
Not only does Europe require the removal of all food products prior to fumigation, it also requires measures to ensure that fluoride residues on the mill machinery do not contaminate food when production resumes. According to a 2010 risk assessment from the European Food Safety Authority (EFSA):
“Even though uses on the fumigation of food items (dried fruits, nuts) were withdrawn during the peer review procedure and only uses for structural treatments remain, there is still the potential for consumer exposure to inorganic fluoride through contaminated products, such as flour and bran that remained in the mill machinery during fumigation, or grain stored in silos in the mill. Available data show that high fluoride residue levels in flour and bran occurred after the production in a treated mill structure had been taken up again. Therefore, if in practice contamination per se cannot be avoided, then measures to avoid contaminated cereal products entering the food chain are necessary.” (EFSA 2010) (emphasis added).
In accord with the EFSA report, the UK government has imposed the following terms of use on ProFume’s Product Label:
Emptying and cleaning
Mills: The mills should be emptied of flour and cleaned. Mill machinery should be run to remove flour retained within the equipment. Flour storage areas and connecting pipes should be emptied or effectively sealed. Bagged flour must be removed to prevent gas penetration.
Contact of ProFume with flour should be avoided.
Food Processing and Storage Facilities: The food processing facility should be emptied of product and cleaned. Food processing machinery should be free of food material within the equipment. Food storage areas, machinery, equipment and connecting pipes should be opened up and or effectively sealed or emptied. All packaged food material including raw ingredients and finished products must be removed or sealed to prevent gas penetration.
Contact of ProFume with other food material should be avoided.
Re-Starting the Mill
Mills: Flour and bran produced in the first flush (i.e. the 10 minutes after restart of full flow of flour) must be collected and sent for disposal/discarded. The next 50 minutes of production must be collected and recycled through the production process. Discarded flour must not be used for human or animal consumption.
Food Processing Facilities: All production lines must be inspected and any residual food material collected and sent for disposal/discarded. Discarded material must not be used for human or animal consumption.
Canada has taken a similar approach. As EPA noted in its Proposed Order, “Canada has imposed restrictions on the use of sulfuryl fluoride for the fumigation of food processing facilities that are designed to insure that no residues result in food.” (Emphasis added)
The notion, therefore, that contaminating foods with sulfuryl fluoride is merely a de minimis matter has been implicitly, if not explicitly, rejected by most western nations. The consensus among these nations is that the marginal increase in costs associated with removing all food prior to fumigation is not sufficient to justify allowing sulfuryl fluoride to enter the food supply. EPA’s proposed order is consistent with this consensus.
It is particularly important that sulfuryl fluoride not be added to food in the United States because, unlike children in the European countries that disallow food-based tolerances, children in the United States have extensive exposure to fluoride from fluoridated drinking water. Indeed, according to the EPA’s latest document on fluoride exposure, children in the United States are already being chronically overexposed to fluoride. Based on the most recent data, “some children drinking water at the 90th percentile intake level up to about age 7 are being exposed to fluoride on a daily basis at levels at or higher than estimated acceptable intake levels when the concentration of fluoride in their drinking water is at or above 0.87 mg/L.” (EPA, 2010b, p.104). Even if all municipal water systems were to lower the level of fluoride to 0.7 mg/L, as has been suggested recently by the Department of Health and Human Services, the upper limit (UL) for fluoride exposure (IOM, 1997) would still be exceeded by about 10% of children under the age of 4 years, even without any contribution from sulfuryl fluoride. (EPA, 2010b, Table 7-1, p.98 and Table 8-2, p.104).