3,3'Dimethylbenzidine [factsheet]

3,3'-DIMETHOXYBENZIDINE

Please Note: The main sources of information for this fact sheet are the Hazardous Substances Data Bank (HSDB), a database of summaries of peer-reviewed literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.

Environmental/Occupational Exposure

* Occupational exposure to 3,3'-dimethoxybenzidine may occur for those workers in dye manufacturing and processing plants. (1,2)

* Dermal exposure to the general population may occur from the use of packaged dyes and pigments for home use derived from 3,3'-dimethoxybenzidine. (2)

Assessing Personal Exposure

* Tests are available that measure 3,3'-dimethoxybenzidine in the urine of exposed individuals. (2)

Health Hazard Information

Acute Effects:

* No information is available on the acute (short-term) effects of 3,3'-dimeth-oxybenzidine in humans.

* Acute animal tests, such as the LD₅₀ test in rats, have shown 3,3'-dimethoxybenzidine to have moderate acute toxicity from oral exposure. (3)

Chronic Effects (Noncancer):

* No information is available on the chronic (long-term) effects of 3,3'-dimeth-oxybenzidine in humans.

* Animal studies have reported effects on the liver, kidneys, and bladder and gastritis, intestinal hemorrhage, and weight loss from exposure via gavage (experimentally placing the chemical in the stomach). (2)

* EPA has not established an RfC or an RfD for 3,3'-dimethoxybenzidine.

Reproductive/Developmental Effects:

* No information is available on the reproductive or developmental effects of 3,3'-dimethoxybenzidine in humans or animals.

Cancer Risk:

* No information is available on the carcinogenic effects of 3,3'-dimethoxybenzidine in humans.

* Animal studies indicate that oral exposure to 3,3'-dimethoxybenzidine results in an increased incidence of tumors of the mammary gland, ovary, bladder, intestine, skin, and stomach. (1,2)

* EPA has classified 3,3'-dimethoxybenzidine as a Group B2, probable human carcinogen. (4)

* EPA's Office of Air Quality Planning and Standards, for a hazard ranking under Section 112(g) of the Clean Air Act Amendments, has ranked 3,3'-dimethoxybenzidine in the nonthreshold category. The 1/ED₁₀ value is 3.1 per (mg/kg)/d and this would place it in the medium category under Superfund's ranking for carcinogenic hazard. (4)

Physical Properties

* 3,3'-dimethoxybenzidine is a colorless crystalline compound that turns violet upon exposure to air. (2)

* The chemical formula for 3,3'-dimethoxybenzidine is C₁₄H₁₆N₂O₂, and the molecular weight is 244.30 g/mol. (2)

* The vapor pressure for 3,3'-dimethoxybenzidine is 8.8 H 10^-9 mm Hg at 25 EC, and it has a log octanol/water partition coefficient (Log K_ow) of 1.81. (1,2)

Uses

* 3,3'-Dimethoxybenzidine is used as an intermediate for the production of dyes and pigments. (2)

Note: There are very few health numbers or regulatory/advisory numbers for 3,3'-dimethoxybenzidine; thus, a graph has not been prepared for this compound.

References

1. U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.

2. U.S. Environmental Protection Agency. Health and Environmental Effects Profile on 3,3-Dimethoxybenzidine. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1987.

3. U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.

4. U.S. Environmental Protection Agency. Technical Background Document to Support Rulemaking Pursuant to the Clean Air ActCSection 112(g). Ranking of Pollutants with Respect to Hazard to Human Health. EPAB450/3-92-010. Emissions Standards Division, Office of Air Quality Planning and Standards, Research Triangle Park, NC. 1994.