 |
Also see:
|
Tributyltin and Associated Chemicals
Description: Tributyltin (TBT) is a chemical categorized with several associated chemicals. It was prominent in news stories last month when German retailers pulled soccer jerseys from store shelves after a television station reported that the jerseys had been treated with tributyltin, which can be toxic to humans. Nike, which manufactured the jerseys, later conducted additional laboratory tests and found the jerseys to be safe. In addition, because British and Dutch tests have shown the substance to cause mutations in marine snails, the World Wildlife Fund has called for its global ban, according to the Associated Press. The tributyltin family of chemicals include bis (tributyltin) oxide, or tributyltin oxide, CAS # 56-35-9; tributyltin sulfide, CAS # 4808-30-4; bis (tributyltin) adipate, CAS # 7437-35-6; tributyltin methacrylate, CAS # 2155-70-6; tributyltin fluoride, CAS #1983-10-4; and tributyltin acetate, CAS # 56-36-0. Tributyltin is used as a fungicide and bactericide in underwater and anti-fouling paints. It is used as a preservative for wood, textile, paper, leather, and glass; as a rodent repellent, insecticide, and biocide; as a water repellant coating, antioxidant, curing agent, and corrosion inhibitor; and in flame resistant polyester. Tributyltin derivatives, which are toxic to gram positive bacteria, are combined with gram negative bactericides for use as disinfectants on surfaces such as hospital floors and sports arenas. Formulations which release tributyltin oxide or tributyltin fluoride in a controlled fashion have been proposed for use as molluscicides. Tributyltin is also used "to kill bacteria and suppress the smell of sweat," according to the Associated Press, which would "seem an ideal additive for sports shirts." Chemical properties: Bis (tributyltin) oxide, the most common of the tributyltin chemicals in the United States, is a colorless to yellow liquid with a weak odor. It is soluble in hot water, and solidifies below -45 degrees C. It is considered to be a bis (triorganotin) oxide, which is a strong base and reacts with inorganic and organic acids forming normal salt-like but non-conducting and water-insoluble compounds. Other synonyms are butinox, hexabutyldistannoxane, and TBTO. Identification: Health effects: Exposure to tributyltin can cause sore throat, cough, rhinitis, hemorrhages of the nasal septum, irritation to the skin and eyes, and retching. Exposure can occur through the ingestion of contaminated fish and through dermal exposure to products containing the chemical. As a bis (triorganotin) oxide, bis (tributyltin) oxide is a potent central nervous system toxin and skin irritant, causing pruritis, or itching; exposure can cause nausea, abdominal cramping, diarrhea, and vomiting. According to the Associated Press, "at high levels in humans, TBT is believed to cause neurological problems, damage to the immune system, and harm the liver, some experts say." According to The New York Times, "it is strongly irritating to skin and can cause burns. It can cause nerve and liver problems." Exposure Values:
Economics: There is currently no information on any companies manufacturing tributyltin. Regulation: Bis (tributyltin) oxide, tributyltin methacrylate, and tributuyltin fluoride are regulated under the Emergency Planning and Community Right-to-Know Act; bis (tributyltin) oxide is also regulated under the Federal Insecticide, Fungicide, and Rodenticide Act, and by the Food and Drug Administration, as an indirect food additive. Under the Emergency Planning and Community Right-to-Know Act, emissions of more than one pound of the tributyltin associated chemicals released into the air, water, and land must be reported annually and entered into the national Toxics 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 |