FACT SHEET ON A DRINKING WATER CHEMICAL CONTAMINANT GENERAL INFORMATION Synonyms • Xylols; Dimethyl benzene Chemical Description: • Mixture of the three isomers of xylene (ortho, mefa and para) Properties: • Clear, colorless, flammable liquid at room temperature • Moderate vapor pressure • Moderately soluble in water Production and Us®: • Occur naturally as a component of petroleum oil, and as a by-product of gasoline refining • Used: • as solvents for paints, lacquers, varnishes, inks, dyes, and adhesives • as a component of detergents • in the manufacture of quartz crystal oscillators, perfumes, and insect repellents ENVIRONMENTAL PROFILE Occurrence: • tow-level contaminant of both ground and surface public water supplies • EFA's Community Water Supply Survey found that 3% of all ground water derived, and 6% of all surface water derived public drinking water systems sampled had levels greater than 0.0005 mg/l Releases: • Releases to the environment are largely to air due to its volatile nature, with smaller amounts to soil and wafer • Releases to water are due to spills and leaks of gasoline and other petroleum products, and from the' disposal of waste from paints, inks, and other industrial products Environmental Fats: • Released to soil: will volatilize rapidly on soli surface, with volatilization rate decreasing with increasing soil depth; will bind somewhat to soils; may chemically and biologically degrade during passage through soil to groundwater • Released to surface water?: will volatilize *a:riy rapidly (dominant removal process) to -he atmosphere where they will photodegrade rapidly; some adsorbtion to sediment will occur; once present in ground wafer, they are not likely to degrade, and may persist for months or years HEALTH EFFECTS Humans: » Inhalation studies have shown that xylenes produce disturbances in the central nervous sytem (CNS) as reflected in changes in numerative ability, short-term memory, body balance, reaction time, and manual coordination Experimental Animais: • Long-term, high dose exposure by inhalation causes detrimental effects upon the CNS, liver, and kidney functions • Inconclusive studies on the fetotoxicity and teratogenicity of xylenes • No evidence of carcinogenic potential REGULATORY PROFILE Existing Regulations: •Clean Air Act (CAA): Not regulated •Clean Water Act (CWA): No criteria established •Resource Conservation and Recovery Act (RCRA): Hazardous waste •Superfund (CERCLA): • Hazardous substance •SARA: Toxic chemical • Federal insecticide, Fungicide, and Rodenttclde Act (FIFRA): Registered • Toxic Substances Control Act (TSCA): Regulated ------- HEALTH INFORMATION Maximum Contaminant Level Goals (MCLG): • Non-enforceable levels based solely on an evaluation of possible health risks and exposure, and taking into consideration a margin for public safety • Set at 10 mg/l to protect against damage to the liver, kidneys, and nervous system MCLG for Xylenes = 10 mg/l (effective July 1992) Maximum Contaminant Levels (MCI): • legally enforceable levels for contaminants in public drinking wafer supplies • Based on health risks associated with the contaminants, analytical methods for their assay, and water treatment feasibility and practicality aspects « Exceedance of the MCI in drinking water may result in adverse effects which will depend upon the contaminant concentration in water, amount of water/contaminant ingested, length of exposure, and other biological parameters MCL for Xylenes = 10 mg/L (effective July 1992) EPA Health Advisories (HA): • Short-term HAs: Provide acceptable concentrations of contaminants in water for uo to 10 day exposures, primarily to evaluate the public health risk resulting from an accidental spill or an emergency contamination situation • Longer-term HAs: Provide guidance for persistent wafer contamination situations to cover a period of up to 7 years • Lifetime HAs: Derived in the same way as an MCLG Heolffo Advisories: • Purge and Trap Column Gas Chromafogrocr ^ with Photoionization and S.-ec'rciv'-c Conductivity Detectors in Series: EPA Method 502.2 • Purged Column Gas Chromatography/Mass Spectrometry: EPA Method 524.1 • Capillary Column Gas Chromatography/Mass Spectrometry: EPA Method 524.2 WATER TREATMENT Permanent Treatment: • Best Available Technology (BAT): « Granular Activated Carbon * Packed Tower Aeration SHORT-TERM HAZARD ELIMINATION » If the drinking water standards are exceeded, install BAT or use an alternative drinking water supply such as bottled water ADDITIONAL HELP • -State or county health officials can indicate a certified laboratory for testing • Experts in the state Department of Environmental Protection or Natural Resources may also be of help • The EPA has toll-free numbers for further information on drinking water quality, treatment technologies, for obtaining Health Advisories, and for other regulatory information • EPA Hotlines are available Monday through Friday • Safe Drinking Water. 800-426-4791 •National Pesticides: 800-858-7376 ~Superfund/RCRA: 800-424-9346 • For information on the Clean Water Act, call (202) 260-7301 • For information on the Toxic Substances Control Act, call (202) 554-1404 • For information on the Clean Air Act, call (919) 541-2777 Short-term HA for a child * 40 mg/l Longer-term HA for a child * 40 mg/L Longer-term HA for an adult = 100 mg/l Lifetime HA = 10 mg/l ANALYTICAL METHODS' « Purge and Trap Gas Chromatography: EPA Method 502.1 EPA Method 503.1 ------- |