vvEPA United State* Environmental Protection Office of Water (MC-4304) EPA-822-F-93-002 October, 1993 Fact Sheet Ambient Aquatic Life Water Quality Criteria for 2,4-Dimethylphenol AUTHORITY Ambient water quality criteria are published pursuant to Section 304(a) of the Clean Water Act and may form the basis for enforceable standards if adopted by a State into water quality standards. The criteria reflect the latest scientific knowledge on the identifiable effects of pollutants on public health and welfare, aquatic life and recreation. They are developed using a process described in the "Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses" (Stephan fiLaL, 1985). BACKGROUND 2,4-Dimethylphenol (2,4-DMP) is a naturally occurring, substituted phenol derived from petroleum or coal tars. 2,4-DMP (l-hydroxy-2,2-dimethylbenzene, m-xylenol, 2,4- xylenol or m-4-xylenol) is used in the manufacture of phenolic antioxidants, disinfectants, solvents, pharmaceuticals, insecticides, fungicides, plasitcizers, rubber chemicals polyphenylene oxide, wetting agents, and dyestuffs. 2,4-DMP is also an additive of lubricants, gasolines, and cresylic acid. 2,4-Dimethylphenol is classified by EPA's Office of Water as a priority pollutant (Section 307(a) of the Clean Water Act). Acute and Chronic Criteria for 2,4-dimethylphenol in this draft document will . supersede guidance given in the previous Ambient Water Quality Criteria for 2.4- dimethvlphenol (U.S. EPA, 1980). These new criteria were derived using improved procedures and additional (more current) information. concentration (i.e., acute exposure) does not exceed 1,300 ugA more than once every three years on the average, and saltwater aquatic organisms and their uses should not be affected unacceptably if the four-day average concentration (i.e., chronic exposure) of 2,4-Dimethylphenol does not exceed 110 ug/1 more than once every three years on the Except where locally important species are very sensitive. * freshwater aquatic organisms and their uses should not be affected unacceptably if the four-day average concentration (i.e., chronic exposure) of 2,4-Dimethylphenol does not exceed 530 ug/1 more than once ever/ three years on the average and if the one-hour average ------- average and if the one-hour average concentration (i.e., acute exposure) does not exceed 270 ug/1 more than once every three years on the average. IMPLEMENTATION INTO STATE STANDARDS Ambient water quality criteria may form the basis for enforceable standards if adopted by a State into water quality standards. States may opt to develop site specific criteria (Water Quality Standards Handbook, December, 1983, EPA#: 440/5-83-011). Replacement of national criteria with site specific criteria may include site specific criterion concentrations, mixing zone considerations (Water Quality Standards Handbook, December, 1983, EPA#: 440/5-83-011), averaging periods and site-specific frequencies of allowed exceedences (Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses, Stephan fl aL. 1985). When the basis for site specific criteria relate to the averaging period, there should be a justification for why variability assumptions underlying national criteria are inappropriate. AVAILABILITY OF DOCUMENT Copies of the proposed criteria document, and other referenced documents, may be obtained from the address below. 2,4-Dimethylphenol Proposal Water Resource Center, (RC-4100) U.S. Environmental Protection Agency 401 M Street, S.W. Washington, D.C., 20460 For further information please contact: Mrs. Amy L. Leaberry U.S. Environmental Protection Agency Office of Water Water Quality Criteria Section (Mail Code - 4304) 401 M Street, SW Washington, DC 20460 ------- |