FACT SHEET ON A DRINKING WATER CHEMICAL CONTAMINANT GENERAL INFORMATION Synonyms: • 2-(2.4.5-Trichlorophenoxy)-Propionic Acid; Silvex; Fenoprop • Trade Names: Aqua-Vex; Ded-Weed; Kuron; Kurosal; Fruitons 1; Silvi-Rhop; Weed-8-Gon Chemical Desclptlon: • Carboxylic acid herbicide Properties: « Commercial formulations of 2,4,5-TF contain small but measureable amounts of 2.3.7,8- tetrachloro-dibenzo-p-dioxin (TCDD). a highly toxic substance • White powder at room temperature • Slightly soluble in water • Low estimated vapor pressure Production and Use: » Prior to 1983, when the EPA cancelled all uses, it was used as an herbicide to control woody plants and weeds in crops, industry (forestry and golf courses), home/garden settings, and in aquatic environments ENVIRONMENTAL PROFILE Occurrence: • Low-level' contamination of a few ground wafer supplies occurred during the 1960's and 1970 s, but because of the cancellation of 2.4.5-TP's uses early in the 1980's, present and future occurrence levels of the chemical are considered to be unlikely » Results of the 1990 National Pesticide Survey (NFS) indicate that 2,4,5-TP was not present in any rural drinking water wells nor in any Community Water System (CWS) wells iefeaset: • Releases to" the environment are expected to * be negligible, but may occur as residual industrial waste or as persistent residues in soil Environmental Fate: • Released to toll: not expected to voiatilize significantly; soil mobility will vary widely with compound formulation and soil type, but generally expected to have low soil mobility (strong adsorption to soil - mobility decreases with decreasing pH) and low potential for migration to ground water; biodegraaation and runoff from treated fields may be significant removal processes • Released to surface water: not exceeded *a volatilize from water; expected to strongiy bind to sediment where slow biodegraaation is expected; phofodegradafion may occur near the surface of wafers • Low potential for b©accumulation HEALTH EFFECTS Humans: • Little data on chronic exposure availacie cur data from case studies of occupational workers in the manufacture of sim-iar chlorophenoxy herbicides indicate that *? may have detrimental effects upon the nervous system Experimental Animals: • One of the major problems in assessing tne effects of 2,4,5-TP is the contamination with varying amounts of 2,3,7.8-TCDD so that s often unclear whether the reported nec^h effects are attributable to 2,4,5-TP. the a;o^n contaminant, or a combination of both • Acute exposure appears to target fhe and kidneys, causing symptoms sucn zs depression, posterior quarter weakness, irritation of the stomac- era minor liver and kidney damage • Long-term exposure causes minor liver o~-a kidney damage • May have teratogenic potential • inadequate studies to determine mutagen:; or carcinogenic potential ------- REGULATORY PROFILE Lifetime HAs: Derived m the same way as an MCLG Existing Standards:- •Clean Air Act (CAA): Wet regulated •Clean Water Act (CWA): No criteria established •Resource Conservation and Recovery Act (RCRA): Hazardous waste •Superfund (CERCLA): •Hazardous substance •SARA; Not regulated •Federal Insecticide, Fungicide, and Rodentlcide Act (FIFRA): Registered •Toxic Substances Control Act (T5CA): Not regulated HEALTH INFORMATION Maximum Contaminant Level Goals (MCLG): • Nan-enforceable levels based solely on an evaluation of possible health risks and exposure, and taking into consideration a margin for public safety • Set at 0.05 mg/L to protect against damage to the liver, kidneys, and nervous system MCLG for 2,4,5-TP = 0.05 mg/L (effective July 1992) Maximum Contaminant Levels (MCL): • Legally enforceable levels for contaminants in oublic drinking water supplies • Sased on health risks associated with the contaminants, analytical methods for their assay, and water treatment feasibility and practicality aspects • Exceedance of the MCL 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 • Current MCL = 0,01 mg/L MCL for 2,4,5-TP = 0.05 mg/l (effective July 1992) EPA Health Advisories (HA): • Short-term HAs: Provide accep'ooie concentrations of contaminants in wafer for up 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 water contamination situations to cover a period of up to ? years Health Advisories: Short-term HA for a child = 0.2 mg L Longer-term HA for a child = 0.07 mg, L Longer-term HA for an adult = 0.3 mg. L Lifetime HA = 0.05 mg/L ANALYTICAL METHODS - • Gas Chromatography with an Electron Capture Detector EPA Method 515.1 WATER TREATMENT Permanent Treatment: • Best Available Technology (BAT): • Granular Activated Carbon SHORT-TERM HAZARD ELIMINATION • If the drinking wafer standards are exceeded, install BAT or us® an alternative drinking water supply such as bottiea water ADDITIONAL HILP • State or county health officials can indicate a certified laboratory for testing • Experts in the state Department of Environmental Protection, Natural Resources, or Agriculture may also be of help • The EPA has toll-free numbers for further information on drinking wafer auality. 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: 800-858-7378 • Superfund/ RC R A: 800-424-9346 • For information on the Clean Wafer Act, call (202) 260-7301 « for information on the Toxic Substances Control Act, call (202) 564-1404 • for information on the Clean Air Act, call (919) 541-2777 ------- |