Phenol [factsheet]

PHENOL

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS), which contains information on oral chronic toxicity and the RfD and the carcinogenic effects of phenol, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for Phenol. 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literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.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

* Individuals may be exposed to phenol through breathing contaminated air or through skin contact in the workplace. (1)

* Other exposures to phenol may occur through the use of phenol-containing medicinal products or smoking tobacco or by eating certain foods such as fried chicken, mountain cheese, and some species of fish. (1)

Assessing Personal Exposure

* Phenol can be detected in urine; this test can be used to determine whether a person has recently been exposed to phenol or to substances that are changed to phenol in the body. However, no test will tell whether a person has been exposed only to phenol, because many substances are changed to phenol in the body. (1)

Health Hazard Information

Acute Effects:

* Inhalation and dermal exposure to phenol is highly irritating to the skin, eyes, and mucous membranes in humans. (1-3)

* Phenol is considered to be very toxic to humans through oral exposure, with ingestion of 1 g reported to be lethal, with symptoms including muscle weakness and tremors, loss of coordination, paralysis, convulsions, coma, and respiratory arrest. (1-3)

* Blood changes, liver and kidney damage, and cardiac toxicity including weak pulse, cardiac depression, and reduced blood pressure have been reported in humans acutely exposed to phenol by the oral route. (1,2)

* Acute (short-term) animal tests, such as the LD₅₀ tests in rats, mice, and rabbits, have shown phenol to have high acute toxicity from oral exposure. (4)

Chronic Effects (Noncancer):

* Limited data are available on the chronic effects of phenol in humans from inhalation or oral exposure. In one study, muscle pain, weakness, enlarged liver and elevated levels of liver enzymes were found in an individual after inhalation and dermal exposure to phenol and a few other chemicals. (1)

* Application of phenol to the skin results in dermal inflammation and necrosis. Cardiac arrhythmias have also been reported in individuals exposed to high concentrations of phenol. (1)

* Long-term inhalation exposure to phenol in animal studies has shown effects on the liver, kidney, respiratory, cardiovascular, and central nervous systems (CNSs). (1)

* The RfD for phenol is 0.6 mg/kg/d based on reduced fetal body weights in rats. (5)

* EPA has low confidence in the study on which the RfD was based because the dose was administered by gavage; medium confidence in the database because it contains several supporting studies (subchronic, chronic, and reproductive/developmental); and, consequently, low-to-medium confidence in the RfD. (5)

* EPA has not established an RfC for phenol. (5)

* 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 phenol for chronic toxicity and has given it a composite score of 44 (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. (6)

* EPA's Office of Air Quality Planning and Standards, for a hazard ranking under Section 112(g) of the Clean Air Act Amendments, considers phenol to be a "high concern" pollutant based on severe chronic toxicity. (6)

Reproductive/ Developmental Effects:

* No studies were located concerning the developmental or reproductive effects of phenol in humans.

* Animal studies have reported reduced fetal body weights, growth retardation, and abnormal development in the offspring of animals exposed to phenol by the oral route. Decreased maternal weight gain and increased maternal mortality were also observed. (1,3)

Cancer Risk:

* No studies were located on the carcinogenic effects of phenol in humans.

* Animal studies have not seen tumors resulting from oral exposure to phenol, while dermal studies have reported that phenol applied to the skin may be a tumor promotor and/or a weak skin carcinogen in mice. (1,2,5)

* EPA has classified phenol as a Group D, not classifiable as to human carcinogenicity, based on a lack of data concerning carcinogenic effects in humans and animals. (6)

Physical Properties

* Phenol is a colorless or white solid when it is pure; however, it is usually sold and used as a liquid. (1)

* The odor threshold for phenol is 0.04 ppm, with a strong very sweet odor reported. (1,7)

* Phenol is very soluble in water and is quite flammable. (2)

* The chemical formula for phenol is C₆H₆O and the molecular weight is 94.144 g/mol. (8,9)

* The vapor pressure for phenol is 0.41 mm Hg at 25 EC, and it has a log octanol/water partition coefficient (Log K_ow) of 1.46. (9)

Uses

* The primary use of phenol is in the production of phenolic resins, which are used in the plywood, construction, automotive, and appliance industries. (1)

* Phenol is also used in the production of caprolactam and bisphenol A, which are intermediates in the manufacture of nylon and epoxy resins, respectively. (1)

* Other uses of phenol include as a slimicide, as a disinfectant, and in medicinal products such as ear and nose drops, throat lozenges, and mouthwashes. (1)

Health Data from Inhalation Exposure

Concentration (mg/m³)	Health numbers^a	Regulatory, advisory numbers^b	Reference
1,000,000.0
_ _ _ _ 100,000.0
_ _ _ _ 10,000.0
_ _ _ _ 1,000.0
_ _ _ _ 100.0
_ _ _ _ 10.0		* NIOSH REL (15 min) (60 mg/m³) * NIOSH REL (20 mg/m³) * NIOSH TLV and OSHA PEL (19 mg/m³)	2 2 2

NIOSH RELCNational Institute of Occupational Safety and Health's recommended exposure limit; NIOSH-recommended exposure limit for an 8- or 10-h time-weighted-average exposure and/or ceiling.

NIOSH TLVCNational Institute of Occupational Safety and Health's threshold limit value; the concentration of a substance to which most workers can be exposed without adverse effects.

OSHA PELCOccupational Safety and Health Administration's permissible exposure limit expressed as a time-weighted average; the concentration of a substance to which most workers can be exposed without adverse effect averaged over a normal 8-h workday or a 40-h workweek.

^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.

References

1. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Phenol. U.S. Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA. 1989.

2. E.J. Calabrese and E.M. Kenyon. Air Toxics and Risk Assessment. Lewis Publishers, Chelsea, MI. 1991.

3. 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.

4. 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.

5. U.S. Environmental Protection Agency. Integrated Risk Information System (IRIS) on Phenol. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1993.

6. 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.

7. J.E. Amoore and E. Hautala. Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. Journal of Applied Toxicology, 3(6):272-290. 1983.

8. U.S. Environmental Protection Agency. Drinking Water Health Advisory on Phenol. Office of Drinking Water, Washington, DC. 1990.

9. U.S. Environmental Protection Agency. Health and Environmental Effects Profile for Phenol. EPA/600/x-87/121. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1987.