1,4-Dioxane Chemistry, Uses, and Occurrence - Environmental Investigation and Remediation - page 80

TABLE 2.6
Common Impurities of 1,4-Dioxane

Impurity Concentration

<0.1%

bis(2-Chloroethyl) ether

Water <0.1%

2-Methyl-1,3-dioxane <0.1%

2-Ethyl-1,3-dioxane ≤0.03%

Hydrogen peroxide ≤0.001%

Lead ≤ 0.25 ppm

Iron < 0.25 ppm

Sources: European Chemicals Bureau, 2002, European Union risk assessment report: 1,4-Dioxane.
Luxembourg, European Union, Institute for Health and Consumer Protection, Report 21;
DeRosa, C.T., Wilbur, S., Holler, J., et al., 1996, Toxicology and Industrial Health 12: 43;
U.S. Environmental Protection Agency (USEPA), 1981, Phase I risk assessment of
1,4-dioxane. U.S. Environmental Protection Agency, EPA Contract No. 68-01-6030; and
VROM, 1999, Risk assessment: 1,4-Dioxane. Bilthoven, Netherlands: S.P. Netherlands
Ministry of Housing and the Environment (VROM), Chemical Substances Bureau 153.

their typical concentrations. Other impurities may also be present in 1,4-dioxane in unspecii ed amounts,
such as acetaldehyde, acetic acid, glycol acetal paraldehyde, and crotonaldehyde (Wypych, 2001).
Low-molecular-weight ethers, including 1,4-dioxane, react with oxygen to form explosive perox-
ides. When 1,4-dioxane comes into contact with oxygen or ultraviolet light, it can form the peroxide
compound 1,4-dioxanyl-2-hydroperoxide (Gierer and Pettersson, 1968). Prolonged exposure to air
and sunlight may form unstable peroxides, particularly when water is absent. Peroxide compounds
can form and accumulate in 1,4-dioxane, which may then explode when subjected to heat or shock.
Handling 1,4-dioxane is most hazardous when peroxide levels are concentrated by distillation or
evaporation. To prevent peroxide formation, 1,4-dioxane is stabilized by adding small amounts of
reducing agents such as stannous chloride or ferrous sulfate. In addition, it can be stabilized with
25 mg/kg 2,6- tert -butyl- p -cresol, a phenolic antioxidant also used to stabilize chlorinated solvents,
or with 25 mg/kg butyl hydroxy toluene (BHT), an antioxidant commonly found in baked goods
(BASF, 1986, 2005; European Chemicals Bureau, 2002). Another method to prevent peroxide for-
mation is i lling container headspace with nitrogen. When stabilized and stored under nitrogen in
original containers, 1,4-dioxane has a shelf life of 24 months (BASF, 2005).

2.3 DIRECT USES OF 1,4-DIOXANE
The leading U.S. producer of 1,4-dioxane, Ferro Corporation, lists the following uses of 1,4-dioxane
on its web site (Ferro Corporation, 2006):

• Wetting and dispersing agent in textile processing

• Dye baths and stain and printing compositions

• Some cleaning and detergent preparations, adhesives, cosmetics, deodorants, fumigants,

emulsions, and polishing agents
Some lacquers, paints, varnishes, and paint and varnish removers •

• Solvent for fats, oils, waxes, and natural and synthetic resins

• Purii cation of drugs

• Reaction media in various organic synthesis reactions

• Stabilizer for chlorinated solvents