Halogenated Solvent Cleaning National Emission Standards for Hazardous Air Pollutants (NESHAP).

In December 1994, EPA issued national regulations (40 CFR 63.462 and 40 CFR 63.463), the primary solvent cleaning air regulations, to control toxic air pollutant emissions from cold cleaning and vapor degreasers that use any of the following halogenated solvents:

• methylene chloride,
• perchloroethylene,
• trichloroethylene,
• 1,1,1-trichloroethane,
• carbon tetrachloride,
• chloroform, or
• any combination of these halogenated HAP solvents.

Since 1994, various updates to the rule have been promulgated by EPA (see More Resources on the Solvent Cleaning page for a complete list of all changes). On May 3, 2007, EPA published revised air emission standards for hazardous air pollutants from halogenated solvent cleaning operations that establish a facility-wide annual emissions limit of 60,000 kg/yr of methylene chloride (MC), perchloroethylene (PCE), and trichloroethylene (TCE), on a "risk-adjusted" basis (see 2007 changes). The current rule consists of seven groups of requirements:

• control combinations or emission limits;
• equipment standards;
• work practice standards;
• testing;
• monitoring;
• recordkeeping; and
• reporting.

The specific requirements for each affected facility depend on the type of machine (e.g., vapor degreaser vs. solvent parts washer) and the date of machine installation.

All in-line cold, in-line vapor, batch vapor, and batch cold solvent cleaning machines using the regulated solvents with at least 5 percent by weight are subject to provisions of this rule. Solvent cleaning machines using less than 5 percent by weight of these Hazardous Air Pollutant (HAP solvents) are exempt from the requirements of the final rule. This rule does not apply to wipe cleaning activities (using a rag or a spray container) or small buckets, pails, and beakers with capacities of 7.6 liters (2 gallons) or less.

Existing machines, constructed or reconstructed on or before November 29, 1993, had until December 2, 1997, to comply with all the provisions of this final rule. New machines, constructed or reconstructed after November 29, 1993, and on or before December 2, 1994, had to comply by December 2, 1994. New machines, constructed or reconstructed after December 2, 1994, must be in compliance with this rule immediately upon startup.

Numerous documents have been published by EPA and state agencies to assist industry with compliance, including pollution prevention approaches. Several resources can be found on the Solvent Cleaning page under More Resources.