2,4Dinitrophenol [factsheet]

2,4-DINITROPHENOL

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS), which contains information on the oral chronic toxicity of 2,4-dinitrophenol and the RfD, and the National Research Council's Drinking Water and Health. Other secondary sources include 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literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.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

* Little information is available on environmental exposure to 2,4-dinitrophenol. The available data suggest that exposure to 2,4-dinitrophenol occurs primarily from pesticide runoff to water. (1)

Assessing Personal Exposure

* No data were located concerning personal exposure to 2,4-dinitrophenol.

Health Hazard Information

Acute Effects:

* Acute (short-term) oral exposure to high levels of 2,4-dinitrophenol in humans has resulted in nausea, vomiting, sweating, dizziness, headache, loss of weight, and other symptoms. The lethal oral dose is reported to be 14 to 43 mg/kg. (2)

* 2,4-Dinitrophenol is considered to have high acute toxicity, based on short-term animal tests such as the LD₅₀ tests in rats and mice. (3)

Chronic Effects (Noncancer):

* Chronic (long-term) oral exposure to 2,4-dinitrophenol in humans and animals has resulted in the formation of cataracts and skin lesions and has caused effects on the bone marrow, central nervous system, and cardiovascular system. (2)

* The RfD for 2,4-dinitrophenol is 0.002 mg/kg/d based on cataract formation in humans. (4)

* EPA has low confidence in the study on which the RfD was based since this study only describes anecdotal data; low confidence in the database since the supporting database is meager; and, consequently, low confidence in the RfD. (4)

* EPA has determined that there are inadequate data for the establishment of an RfC for 2,4-dinitrophenol. (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 evaluated 2,4-dinitrophenol for chronic toxicity and has given it a composite score of 30 (scores range from 1 to 100, with 100 being the most toxic). These scores are nonlinear and are the product of two ratings: a rating based on the minimal-effect-dose and a rating based on the type of effect. (1)

* EPA's Office of Air Quality Planning and Standards, for a hazard ranking under Section 112 (g) of the Clean Air Act Amendments, considers 2,4-dinitrophenol to be a "high concern" pollutant based on severe chronic toxicity. (1)

Reproductive/Developmental Effects:

* No information is available on the reproductive or developmental effects of 2,4-dinitrophenol in humans.

* The available animal studies reported fetal growth inhibition, but no birth defects in the offspring of animals fed 2,4-dinitrophenol. (5)

Cancer Risk:

* No information is available on the carcinogenic effects of 2,4-dinitrophenol in humans.

* One oral study in mice reported no tumor formation after 6 months exposure, but another study reported that 2,4-dinitrophenol did not promote tumor development in mice. (5)

* EPA has not classified 2,4-dinitrophenol for potential carcinogenicity. (1)

Physical Properties

* The chemical formula for 2,4-dinitrophenol is C₆H₄N₂O₅ and the molecular weight is 184.11 g/mol. (6)

* The vapor pressure for 2,4-dinitrophenol is 1.42 H 10^-7 mm Hg at 25 EC, and its log octanol/water partition coefficient is 1.91. (7)

* 2,4-Dinitrophenol exists as yellowish crystals, is slightly soluble in water, and is volatile with steam. (6)

* The odor threshold for 2,4-dinitrophenol is not available.

Uses

* 2,4-Dinitrophenol is used in the manufacture of dyes and wood preservatives and as a pesticide. (6)

* 2,4-Dinitrophenol is also used as an indicator for the detection of potassium and ammonium ions. (6)

Health Data from Oral Exposure

Concentration (mg/kg/d)	Health numbers^a	Regulatory, advisory numbers^b	Reference
100.0
_ _ _ _ 10.0	* LD₅₀ (cats) (75 mg/kg) * LD₅₀ (mice) (45 mg/kg) * LD₅₀ (rats) (30 mg/kg)		3 3 3
_ _ _ _ 1.0	* LOAEL^c (humans) (2 mg/kg/d)		4
_ _ _ _ 0.1
_ _ _ _ 0.01
_ _ _ _ 0.001	* EPA RfD (0.002 mg/kg/d)		4

LD₅₀ (Lethal Dose₅₀)CA calculated dose of a chemical in water to which exposure for a specific length of time is expected to cause death in 50% of a defined experimental animal population.

LOAELCLowest-observed-adverse-effect level.

RfDCReference dose.

^a Health numbers are toxicological numbers from animal testing or risk assessment values developed by EPA.

^b Regulatory numbers are values that have been incorporated in Government regulations, while advisory numbers are nonregulatory values provided by the Government or other groups as advice.

^c The LOAEL is from the critical study used as the basis for the EPA RfD.

References

1. U.S. Environmental Protection Agency. Technical Background Document to Support Rulemaking Pursuant to the Clean Air Act - Section 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.

2. National Research Council. Drinking Water and Health. Volume 4. National Academy Press, Washington, DC. 1982.

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. Integrated Risk Information System (IRIS) on 2,4-Dinitrophenol. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1993.

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

6. The Merck Index. An Encyclopedia of Chemicals, Drugs, and Biologicals. 11th ed. Ed. S. Budavari. Merck and Co. Inc., Rahway, NJ. 1989.

7. U.S. Environmental Protection Agency. Assessment Tools for the Evaluation of Risk (ASTER, online database). Environmental Research Laboratory, Duluth, MN. 1993.