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Naphthalene
Description: Naphthalene (C.A.S. 91-20-3) is a white solid with a strong smell; is also called mothballs, moth flakes, white tar, and tar camphor. Naphthalene is a natural component of fossil fuels such as petroleum and coal; it is also formed when natural products such as wood or tobacco are burned. The principal use for naphthalene is as an intermediate in the production of phthalic anhydride, which is used as an intermediate in the production of phthalate plasticizers, resins, phthaleins, dyes, pharmaceuticals, insect repellents, and other materials; other products made from naphthalene are moth repellents, in the form of mothballs or crystals, and toilet and diaper pail deodorant blocks. Naphthalene is also used for making leather tanning agents, and the insecticide carbaryl. There are two common compounds related to naphthalene: 1-methylnaphthalene (C11H10, CAS #90-12-0), also called alpha-methylnaphthalene; and 2- ethylnaphthalene (C11H10, CAS #91-57-6), called beta-methylnaphthalene. Chemical properties: Naphthalene evaporates easily; when its vapors are mixed with air, the mixture can burn easily. It is soluble in benzene, alcohol, ether, and acetone; it is soluble in water at 20 degrees C. It is a moderate fire hazard when exposed to heat or flame; it reacts with oxidizing materials and chromium anhydride. It is a moderate explosion hazard, in the form of dust, when exposed to heat or flame. Synonyms for naphthalene are naphthalin, naphthaline, tar camphor, white tar, NCI-C52904, albocarbon, and naphthene. Identification: Health effects: Exposure to a large amount of naphthalene can cause red blood cells to be damaged or destroyed, a condition called hemolytic anemia, which leads to fatigue, lack of appetite, restlessness, and a pale appearance. Naphthalene is more dangerous to African-Americans and people of Mediterranean descent, because these populations have a higher incidence of problems with the enzyme which helps produce red blood cells. Exposure to naphthalene can cause systemic reactions, including nausea, headache, diaphoresis, hematuria, fever, anemia, liver damage, vomiting, convulsions, and coma. Exposure can also cause eye irritation, confusion, excitement, malaise, abdominal pain, irritation to the bladder, profuse sweating, jaundice, hematopoietic, hemoglobinuria, renal shutdown, and dermatitis. Poisoning may occur by ingestion of large doses, skin and/or eye contact, inhalation, or skin absorption. Members of the general population most likely to have high levels of exposure to naphthalene are users of naphthalene-containing moth repellents (including infants exposed to blankets or clothing stored in naphthalene-containing mothballs), smokers, and those in proximity to smokers. Workers in naphthalene-producing or naphthalene-using industries could be subject to heightened exposures, and individuals living or working near hazardous waste sites at which naphthalene has been detected could also be exposed to higher naphthalene concentrations if they come into contact with contaminated media. Exposure Values: Economics: U.S. manufacturers of Nephthalene are: Allied-Signal Inc, Morristown, NJ; Chemical Exchange Industries, Inc., Houston, TX; Koppers Industries, Inc., Pittsburgh, PA ; and Texaco Inc, White Plains, NY. Regulation: Naphthalene is regulated under the Clean Air Act; Comprehensive Environmental Response, Compensation, and Liability Act; Federal Insecticide, Fungicide, and Rodenticide Act; Clean Water Act (as a pollutant on the Priority Pollutants List); the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA); and Resource Conservation and Recovery Act, as a toxic waste. Under Section 313 of the Emergency Planning and Community Right to Know Act of 1986, releases of more than one pound of naphthalene into the air, water, and land must be reported annually and entered into the Toxic Release Inventory (TRI). National Overview of 1998 Toxics Release Inventory See EPA's Toxic Release Inventory. Notations: The NIOSH recommended exposure limits (RELs) are time-weighted average (TWA) concentrations for up to a 10-hour workday during a 40-hour workweek. A short-term exposure limit (STEL) is designated by "ST" preceding the value; unless noted otherwise, the STEL is a 15-minute TWA exposure that should not be exceeded at any time during a workday. A ceiling REL is designated by "C" preceding the value. Any substance that NIOSH considers to be a potential occupational carcinogen is designated by the notation "Ca." The OSHA permissible exposure limits (PEL) are found in Tables Z-1, Z-2, and Z-3 of the OSHA General Industry Air Contaminants Standard (29 CFR 1910.1000). Unless noted otherwise, PEL are TWA concentrations that must not be exceeded during any 8-hour workshift of a 40-hour workweek. A STEL is designated by "ST" preceding the value and is measured over a 15-minute period unless noted otherwise. OSHA ceiling concentrations (designated by "C" preceding the value) must not be exceeded during any part of the workday; if instantaneous monitoring is not feasible, the ceiling must be assessed as a 15-minute TWA exposure. In addition, there are a number of substances from Table Z-2 (e.g., beryllium, ethylene dibromide, etc.) that have PEL ceiling values that must not be exceeded except for specified excursions. For example, a "5-minute maximum peak in any 2 hours" means that a 5-minute exposure above the ceiling value, but never above the maximum peak, is allowed in any 2 hours during an 8-hour workday. Information Sources:
Originally published in Environment Writer by the National Safety Council. Reprinted with permission. Environment Writer Metcalf Institute for Marine and Environmental Reporting University of Rhode Island Graduate School of Oceanography Office of Marine Programs Narragansett, RI 02882 Tel: 401-874-6211; Fax: 401-874-6485 Disclaimer * Copyright 2002-2006 * All rights reserved. * University of Rhode Island |