1,1,1 -trichloroethane regulations

Trichloroethylene use has declined as a result of environmental concerns. However, trichloroethylene may replace some 1,1,1-trichloroethane appHcations. Perchloroethylene used in small businesses for dry cleaning will be regulated for emissions under the same guidelines as those that govern the large chemical producers. This will cause replacement of perchloroethylene for those appHcations where recovery is uneconomical. Methylene chloride has been classified as a suspected carcinogen and its use will decline in aerosol and paint stripping appHcations because of health concerns. 

Clean Air Act 1990 Amendments will lead to a phase out of 1,1,1-trichloroethane by the year 2005, which in turn will likely result in a slight resurgence of trichloroethylene in vapor-degreasing appHcations. The total production, however, will probably stay relatively low because regulations will require equipment designed to assure minimum emissions. 

Preparatory to painting, the polypropylene components are subjected to trichloroethylene or 1,1,1 -trichloroethane which (especially if fillers or other materials are present in the composition) will remove grease and permeate the surface. However, it should be remembered that for environmental and health reasons the use of solvents like these is regulated strictly. 

The Environmental Protection Agency (EPA) sets regulations on the levels of 1,1,1-trichloroethane which are allowable in drinking water. The highest level of 1,1,1-trichloroethane allowed in drinking water is 0.2 ppm. The EPA has decided that the level of 1,1,1-trichloroethane in lakes and streams should not be more than 18 ppm. This level would prevent possible harmful health effects from drinking water and eating fish contaminated with 1,1,1-trichloroethane. Any releases or spills of... 

Trichloroethane levels in the workplace are regulated by the Occupational Safety and Health Administration (OSHA). The workplace exposure limit for an 8-hour workday, 40-hour workweek is 350 ppm in air. See Chapter 7 for more information on regulations and advisories regarding... 

Animal experiments provide supporting evidence that inhaled 1,1,1-trichloroethane is rapidly and extensively absorbed and that the absorption, during short-term exposures, is influenced by ventilation rate. In rats exposed to 50 or 500 ppm, percentage uptake decreased from - 80% at the onset of exposure to - 50% after 2 hours of exposure to 50 or 500 ppm. 1,1,1-Trichloroethane was detected in arterial blood within 2 minutes ofthe onset of exposure and approached steady-state concentrations within 2 hours (Dallas et al. 1989). In anesthetized dogs under regulated respiration conditions, 1,1,1-trichloroethane was detected in arterial blood within 2 minutes of the onset of exposure to 700, 1,500, or 3,000 ppm. Arterial blood concentrations approached steady-state levels within 1 hour at 700 ppm, but not at 1,500 or 3,000 ppm absorption increased with increases in pulmonary ventilation rate (Hobara et al. 1982, 1983). 

There are a few food monitoring studies in the literature that provide several examples of food contamination with 1,1,1-trichloroethane. The ubiquitous nature of 1,1,1-trichloroethane suggests that additional information in this area would allow a complete determination ofthe levels of human exposure to this chlorinated solvent. The release of 1,1,1-trichloroethane to the environment is well established since there are numerous studies that indicate the presence of this compound in environmental media. The quantity of 1,1,1-trichloroethane released to the environment during its production, formulation, and use is known. 1,1,1-Trichioroethane is listed on the Toxics Release Inventory. Methods for the disposal of 1,1,1-trichloroethane exist. Data on the removal of 1,1,1-trichloroethane from waste streams during biological treatment processes are lacking. Information on the amount of 1,1,1-trichloroethane disposed of annually is scarce. Rules and regulations... 

The international, national, and state regulations and guidelines regarding 1,1,1-trichloroethane in air, water, and other media are summarized in Table 7-1. 

TABLE 7-1. Regulations and Guidelines Applicable to 1,1,1-Trichloroethane (continued)... 

Conventional SB systems, with unlimited solvent use, are estimated to have accounted for 31% of the dollar volume of IF shipments in 1982 they are expected to decrease to 12% in 1987 as the full effects of environmental regulations are established. Conforming SB systems, that is, those conforming to the revised California Rule 66, CARB (California Air Resources Board) codes, and the evolving EPA regulations, will decrease at a lower rate, from 34% in 1982 to 22% in 1987. These include the use of certain chlorinated solvents (e.g., 1,1,1-trichloroethane and methylene chloride) that have been exempted by several regulatory authorities. However, problems with reaction with coating application equipment components made of aluminum may impede their full utilization. 

A less preferred way of unloading railroad cars is with the use of air pressure. This is considered appropriate for per-chloroethylene, 1,1,1-trichloroethane, and trichloroethylene as long as not more than 20 psig (138 kPa) of pressure is applied and the car is equipped with a 25-psi (172-kPa) pressure relief valve in accordance with the Department of Transportation (DOT) regulations. When using air, the following steps should be followed ... 

Uses Herbicide plant growth regulator Tri-Ethane. See 1,1,1-Trichloroethane Triethanolamine... 

Maximum exposure limits (MEL) This is the maximum concentration of an airborne substance, averaged over a reference period, to which employees may be exposed by inhalation under any circumstances. Details of the legal requirements are contained in Schedule 1 of the COSHH Regulations and the relevant substances are listed in the first part of the HSE s Guidance Note EH 40. Currently there are 32 substances listed but this is reviewed each year. A few selected examples are hardwood dust, rubber fume, cadmium and compounds and 1.1.1-trichloroethane. 

Solvent use is controlled by both state and federal regulations. The federal Clean Air Act Amendments of 1990 mandate controls on solvent use in the industry. Almost all organic solvents are classified as Volatile Organic Compounds (VOCs) under Title I of the 1990 Amendments and these regulations will require further reductions in future solvent use. Title III of the 1990 Amendments contains a long list of substances considered Hazardous Air Pollutants (HAPs). Many of the halogenated solvents are on the HAP list. The solvents discussed in this chapter and that are on the HAP list include methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, 1,2-dichloroethane, 1,2-dibromoethane, bromoform, and chlorobenzene. The Maximum Achievable Control Technology (MACT) stan-... 

---