1,4-Dioxane Chemistry, Uses, and Occurrence - Environmental Investigation and Remediation - page 99

TABLE 2.14
1,4-Dioxane in Japanese Dietary Food Groups

Dietary
Group

1,4-Dioxane Content
(

Total Dietary Intake
( Foods μ g/kg) μ g)

I Rice, rice noodles ND 0

II Oatmeal, wheat l our, bread, buckwheat,

cornl akes, sweet potato, almonds, instant
noodles, potato, taro root

6 0.057

III Sugar, jam, caramel, rice cracker, pound cake,

chocolate, others

6 0.010

IV Butter, margarine, soybean oil, lard, dressing 8 0.008

V Soybean paste, tofu, frozen tofu, deep fried tofu 3 0.006

VI Orange, apple, banana, strawberry, tomato juice,

watermelon, apricot, loquat

4 0.0026

VII Carrot, spinach, green pepper, tomato, broccoli,

celery, okra

3 0.015

VIII Daikon radish, cucumber, onion, cabbage, bean

sprouts, pickles, pickled relish, mushroom,
green seaweed

8 0.076

IX Soy sauce, ketchup, salt, sauce, sake, beer, wine,

tea, soft drinks

7 0.070

X Salmon, tuna, mackerel, l ati sh, scallop, salted

cod, bonito, sardine

5 0.022

XI Beef, pork, chicken, lamb, ham, chicken, eggs 6 0.055

XII Milk, cheese, yoghurt, sake sediment 13 0.095

Source: Nishimura, T., Iizuka, S., Kibune, N. et al., 2004, Journal of Health Science 50(1): 101-107.
ND = not detected

this daily value equates to 2.7 × 10 -7 mg/kg, which is about 40,000 times less than the suggested
Integrated Risk Information System daily oral slope factor for estimated carcinogenic risk, that is,
1.1 × 10 -2 mg/kg. The FDA concluded that there is reasonable certainty that no harm from exposure
to 1,4-dioxane would result from the daily consumption of ice cream (FDA, 1999).
Glycerides and polyglycides of hydrogenated vegetable oils, also known as PEG esters, may
also contain 1,4-dioxane as an impurity. Glycerides include mixtures of mono-, di-, and triglyc-
erides, whereas polyglycides include PEG mono- and diesters of fatty acids. The Code of Federal
Regulations Title 21, Food and Drugs, sets limits for allowable 1,4-dioxane in food and excipients
of dietary supplements at no greater than 10 mg/kg (FDA, 2006). Consumption of glycerides and
polyglycides in dietary supplement tablets, capsules, and liquid formulations produces an exposure

TABLE 2.15
Emulsifi ers in Which 1,4-Dioxane May Form at Trace Levels
Emulsifi er Name

Chemical Description Uses

Polysorbate 20 Polyoxyethylene sorbitan monolaurate Emulsii er

Polysorbate 80 Polyoxyethylene sorbitan mono-oleate Emulsii er, l avoring, surfactant, defoaming agent

Polysorbate 40 (BAN) Polyoxyethylene sorbitan monopalmitate Emulsii er (from animal fatty acids)

Polysorbate 60 Polyoxyethylene sorbitan monostearate Emulsii er

Polysorbate 65 Polyoxyethylene sorbitan tristearate Emulsii er

Source: Food and Drug Administration (FDA), 1999, Federal Register 64: 57974-57976.