United States Environmental Protection Agency Office of Water 4601 EPA 811-F-95-004p-T October 1995 oEPA National Primary Drinking Water Regulations Toluene CHEMICAL/ PHYSICAL PROPERTIES OCTANOL/WATER PARTITION(KOW): Log Kow = 2.69 CAS NUMBER: 108-88-3 ' . SOLUBILITY: N/A; Slightly soluble in water COLOR/ FORM/ODOR: Colorless liquid with a sweet, benzene- SolL SORPTION COEFFICIENT: like odor BlOCONCENTRATION FACTOR: BCFs: <100 in fish; <10 in shellfish; 380 in algae; not expected to bioconcentrate in aquatic organisms. M.P.: -95° C B.P.: 111°C VAPOR PRESSURE: 36.7 mm Hg at 30° C DENSITY/SPEC. GRAV.: 0.866 at 20° C HENRY'S LAW COEFFICIENT: N/A Koc measured at 37 to 178 in several soils; very high to moderate mobility in TRADE NAMES/SYNONYMS: soil Methylbenzene, Methacide, Phenylmethane, Toluol, Antisal 1A ODOR/TASTE THRESHOLDS: Odor and taste thresholds in water are reported as 0.04 and 1 mg/L DRINKING WATER STANDARDS MCLG: 1 mg/L MCL: 1 mg/L HAL(child): 1 day: 20 mg/L Benzene, 46%; gasoline blending, 37%; solvent, 8%; toluene diisocyanate, 7%; miscellaneous chemicals, 2%. The largest chemical use for toluene is the production of benzene and urethane via hydrodealkylation. Longer-term: 2 mg/L HEALTH EFFECTS SUMMARY Acute: EPA has found toluene to potentially cause the following health effects from acute exposures at levels above the MCL: low oral toxicity to central nervous system, may cause fatigue, nausea, weakness, confu- sion. Drinking water levels which are considered "safe" for short-term exposures: Fora 22 Ib. child consuming 1 liter of water per day: a one-day exposure to 20 mg/L; upto a 7-year exposure to 2 mg/L. Chronic: Toluene has the potential to cause the following health effects from long-term exposures at levels above the MCL: spasms, tremors, imbalance; impairment of speech, hearing, vision, memory, coordi- nation; liver and kidney damage. Cancer: There is inadequate evidence to state whether or not toluene has the potential to cause cancer from lifetime exposures in drinking water. 'JSAGE PATTERNS Production of toluene has increased: from 5.1 billion Ibs. in 1985 to 6.4 billion Ibs in 1993. In 1985, it was estimated that industries consumed toluene as follows: Toxic RELEASE INVENTORY - RELEASES TO WATER AND LAND: 1987 Water TOTALS* (in pounds) 732,31 0 Top Ten States* TX 16,285 CA 0 CT 316,068 OK 0 VA 27,500 VI 2,970 IL 56 Ml 0 WV 117,523 SC 6,000 Major Industries* Petroleum refining 227,196 Medicinals, botanicals 301,585 Petroleum/coal prods. . 38,856 Misc Ind. Chemicals 179,576 Gaskets, sealing devices 4,002 Wood office furniture 0 Plastics, resins 57,661 Wood home furniture 30,000 Paints, allied products 5,927 * Water/Land totals only include facilities with greater than 10,000 Ibs. ro 1993 Land 3,672,041 969,210 930,000 0 287,000 216,000 191,504 180,824 129,226 1,377 89,578 2,580,941 1,108 287,000 107,159 216,000 129,226 39,139 65,444 88,024 releases October 1995 Technical Version ------- Other uses include; manufacture of benzoic acid, benzaldehyde, explosives, dyes, and many other or- ganic compounds; as a solvent for paints, lacquers, gums, resins; in the extraction of various principles from plants; as gasoline additive; as a diluent for photogravure inks; in cements, solvents, spot removers, cosmetics, antifreezes; an asphalt and naphtha constituent; in deter- gent manufacture; in fuel blending RELEASE PATTERNS Toluene is released into the atmosphere principally from the volatilization of petroleum fuels and toluene- based solvents and thinners and from motor vehicle exhaust. Considerable emissions are from: its discharge into waterways or spills on land during the storage, transport and disposal of fuels and oils; from its produc- tion from petroleum and coal; as a by-product from styrene production, and from its use as a chemical intermediate. From 1987 to 1993, according to EPA's Toxic Chemi- cal Release Inventory, toluene releases to land and water totalled over 4 million Ibs., of which about 83 percent was to land. These releases were primarily from petroleum refining industries. The largest releases oc- curred in Texas and California. The largest releases directly to water occurred in Connecticut and West Vir- ginia. ENVIRONMENTAL FATE If toluene is released to soil, it will be lost by evapora- tion from near-surface soil and by leaching to the ground- water. Based on the reported Koc values, toluene will be expected to exhibit very high to moderate in soil and therefore may leach to the groundwater. Field data from infiltration sites is conflicting; in one study toluene is eliminated during bank infiltration, while in other studies it penetrates infiltration sites. These results may bear on site-related factors such as load, flow rate, soil character- istics, and other loss factors such as evaporation and biodegradation. Reported Koc values: Wendover silty loam, 37, Grimsby silt loam, 160, Vaudreil sandy loam, 46; sandy soil, 178; 100 and 151. Biodegradation occurs both in soil and groundwater, but it is apt to be slow especially at high concentrations, which may be toxic to microorganisms. The presence of acclimated microbial populations may allow rapid bio- degradation. Toluene completely degraded in ground- water in 8 days including a lag of 3-4 days while microbial populations became acclimated. Other investigators found that only 1-2% of toluene degraded in the subsurface environment and less than 90% degraded in 4 weeks in soil cores at various depths both above and below the water table. It will not significantly hydrolyze in soil or water under normal environmental conditions. If toluene is released into water, its removal can be rapid or take several weeks, depending on temperature, mixing conditions, and acclimation of microorganisms. Toluene evaporates rapidly from water with an experi- mentally determined half-life of 2.9 to 5.7 hrfor evapora- tion from 1 m of water with moderate mixing conditions. In a mesocosm experiment with simulated conditions for Narragansett Bay, Rl, the loss was primarily by evapora- tion in winter with a half-life of 13 days. It will not signifi- cantly adsorb to sediment. If toluene is released to the atmosphere, it will degrade by reaction with photochemically produced hydroxyl radi- cals (half-life 3 hr to slightly over 1 day) or be washed out in rain. It will not be subject to direct photolysis. It will not significantly bioconcentrate in aquatic organ- isms. Reported BCFs: eels, 13.2; Manila clam, 1.67; mussel, 4.2; algae, 380; golden ide fish, 90. The primary source of human exposure is from inhala- tion of contaminated ambient air, especially in traffic or near filling stations, or in occupational atmospheres where toluene-based solvents are used. OTHER REGULATORY INFORMATION MONITORING: FOR GROUND/SURFACE WATER SOURCES: INITIAL FREQUENCY- 4 quarterly samples every 3 years REPEAT FREQUENCY- Annually after 1 year of no detection TRIGGERS - Return to Initial Freq. if detect at > 0.0005 mg/L ANALYSIS: REFERENCE SOURCE EPA 600/4-88-039 METHOD NUMBERS 502.2; 524.2 TREATMENT; BEST AVAILABLE TECHNOLOGIES Granular Activated Charcoal and Packed Tower Aeration FOR ADDITIONAL INFORMATION: 4 EPA can provide further regulatory and other general information: • EPA Safe Drinking Water Hotline - 800/426-4791 * Other sources of toxicological and environmental fate data include: Toxic Substance Control Act Information Line - 202/554-1404 • Toxics Release Inventory, National Library of Medicine - 301/496-6531 Agency for Toxic Substances and Disease Registry - 404/639-6000 October 1995 Technical Version Page 2 ------- |