Regulation and Risk Assessment of 1,4-Dioxane - Environmental Investigation and Remediation - page 291

6.4.1.2 1,4-Dioxane in Ice Cream
1,4-Dioxane can also be present in polysorbate 60, * an emulsii er in ice cream, frozen custard, fruit
sherbet, and other frozen desserts (FDA, 1999a). Polysorbate 60, in combination with polysorbate
65 and/or polysorbate 80, is added to ice cream in concentrations of 0.2-0.5% to stabilize the mix-
ture of water, milk fat, milk protein (serum solids), sucrose or glucose sweeteners, and l avorings.
Polysorbates 60, 65, and 80 are made by reacting fatty acids with sorbitol. Polysorbates prevent
l avor oils such as vanilla, strawberry, and lemon from separating out of ice creams, beverages, and
candies and extend the shelf life of doughnuts and other pastries (Klockenbrink, 1987). Sorbates are
used to inhibit yeast growth in low-pH food products, such as wine, fruit juice, dried fruit, cottage
cheese, meat, i sh products, salad dressings, tomato products, and carbonated beverages (deMan,
1999). Polysorbates are also used in preparation of chewing gum, emulsii ed sauces, soups, and can-
dies (ECSCF, 2002b). All polysorbates are likely to contain trace amounts of 1,4-dioxane.
The FDA estimated that exposure to 1,4-dioxane from using polysorbate 60 to produce frozen
dairy desserts does not exceed 19 ng/person/day. The FDA estimates that the upper-bound limit of
lifetime human risk from using polysorbate 60 in frozen dairy desserts is 6.7 10 −10 or 6.7 in

10 billion. The European Union's Health & Consumer Protection Directorate-General published
an opinion on the impurities of ethylene oxide in food additives. The polysorbates † are all required
to meet a purity criterion of less than 5 mg of 1,4-dioxane per kilogram of polysorbate (ECSCF,
2002a).

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6.4.1.3 1,4-Dioxane in Gluten-Free Bread
Preparation of gluten-free bread uses modii ed cellulose, including ethyl hydroxyethyl cellulose
(EHEC). EHEC contains trace amounts of 1,4-dioxane as an impurity. The European Commission's
Scientii c Committee on Food recommends that EHEC can be permitted for use in gluten-free
bread at mass fractions of less than 0.5%. If it is assumed that an individual consumes 300 g of
bread or other gluten-free baked goods per day, the corresponding daily exposure to 1,4-dioxane is
estimated to be 0.5 μg of 1,4-dioxane (ECSCF, 2002b). The daily dose from this consumption would
be 0.008 μg 1,4-dioxane per kilogram body weight, which is considerably smaller than the overall
NOAEL for the prevention of liver damage, 10 mg/(kg d). Gluten-free bread also includes polysor-
bates, which can contribute to 1,4-dioxane consumption. The potential maximum daily exposure of
1,4-dioxane from the permitted use of EHEC and polysorbates in bread is 0.008 and 0.05 μg/kg
body weight, that is, about 170,000 times lower than the daily 10 mg/kg NOAEL, and is therefore
of no toxicological concern (ECSCF, 2002b).

6.4.1.4 1,4-Dioxane in Food-Packaging Materials
1,4-Dioxane occurs as an impurity in 10 food-packaging materials and one sanitizing solution
used on food-contact surfaces (U.S. Congress, 1987). Food-packaging materials generally include
1,4-dioxane as an impurity of ethoxylated surfactants; however, 1,4-dioxane may also be introduced
through methyl chloroform used in adhesives, coatings, and labeling systems. For example, adhe-
sives in microwave popcorn bags contained methyl chloroform and 1,4-dioxane and produced mea-
surable worker exposure at a plant that manufactured the popcorn packages (Crandall and Wilcox,
1987). Polymer i lms used to wrap food for refrigeration or retail packaging are classii ed as Indirect
Food Additives in Title 21 of the Code of Federal Regulations. Phosphate compounds used in
cellophane coating, including mono- and bis-(octadecyldiethylene oxide)phosphates may contain
1,4-dioxane as an impurity of manufacturing.

* Also called Tween 60 or Polyoxyethylene (20) sorbitan monostearate.
† Polyoxyethylene (40) stearate; polyoxyethylene sorbitan monolaurate (polysorbate 20); polyoxyethylene sorbitan
monooleate (polysorbate 80); polyoxyethylene sorbitan monopalmitate (polysorbate 40); polyoxyethylene sorbitan
monostearate (polysorbate 60); polyoxyethylene sorbitan tristearate (polysorbate 65); polyethylene glycol 6000.