State Regulations Resulting from
Federal Control Techniques Guidelines (CTGs).

Control Techniques Guidelines (CTGs) are documents issued by EPA to provide States with recommendations on how to control the emissions of Volatile Organic Compounds (VOCs) from a specific type of product or source category in an ozone nonattainment area (a locality where air pollution levels persistently exceed National Ambient Air Quality Standards). The Clean Air Act (CAA) allows EPA to issue CTGs in place of national regulations when the EPA determines that a CTG will be substantially as effective as a regulation in reducing VOC emissions. The CTG provides states with the EPA's recommendation of what constitutes a Reasonably Available Control Technology (RACT) for the covered category. The Industrial Cleaning Solvents CTG was published by EPA in 2006 (EPA 453/R-06-001). This CTG applies to industries that use organic solvent for cleaning unit operations such parts cleaners and emits at least 6.8 kg/day (15 lb/day) of VOC.

The Clean Air Act requires that states include RACTs in their State Implementation Plans or SIPs (enforceable plan developed at the state level that explains how the state will comply with air quality standards according to the Federal Clean Air Act), for sources of emissions in nonattainment areas. EPA defines RACT as "the lowest emission limitation that a particular source is capable of meeting by the application of control technology that is reasonably available considering technological and economic feasibility."

Each CTG includes a "presumptive norm'' or "presumptive RACT'' that the EPA believes satisfies the definition of RACT. If a state submits a RACT rule that is consistent with the presumptive RACT, the state does not need to submit additional support to demonstrate that the rule meets the Clean Air Act's RACT requirement. However, if the state decides to submit an alternative emission limit or level of control for a source or source category for which there is a presumptive RACT, the state must submit independent documentation as to why the rule meets the statutory RACT requirement. This rule causes some variation of solvent cleaning standards from state to state and even within states.

EPA's recommended measures for controlling emissions of VOC from solvent cleaning includes:

• Work practice standards.
• Covering open containers and used applicators.
• Minimizing air circulation around cleaning operations.
• Properly disposing of used solvent and shop towels.
• Implementing equipment practices that minimize emissions (e.g., keeping parts cleaners covered, maintaining cleaning equipment to repair solvent leaks, etc.).
• Limitations on VOC content of the cleaning materials (VOC content limit of 50 grams VOC per liter (0.42 1b/gal) of cleaning material).
• An optional alternative limit to VOC content (8 millimeters of mercury composite vapor pressure of the cleaning materials).
• Also, the use of add-on controls with an overall emission reduction of at least 85 percent by mass.

States can adopt these recommendations and include them in their SIP revisions or adopt RACT rules that provide for different approaches. For example, for a given industrial sector or cleaning operation, where appropriate, a state may offer the flexibility of requiring only work practices. Regardless of the approach a state pursues in its RACT rule, EPA reviews the State RACT rule as part of the SIP approval process and makes the final determination as to whether the State rule comports with the RACT requirements of the Act.

Other State Regulations

States may implement regulations and standards for solvent cleaning that are not specifically related to CTGs and/or are more stringent than the federal regulations, including NESHAPs and RACT rules. This causes some variation of solvent cleaning standards from state to state. The following are examples:

• Illinois requires cold solvent cleaning operations to use solvents having a vapor pressure of 2 millimeters or less of mercury (see Illinois Cold Cleaning regulations).
• Indiana's rule for cold solvent cleaning (326 IAC 8-3-8) prohibits the sale of solvents for use in degreasing operations with a vapor pressure that exceeds one (1) millimeter of mercury.

Therefore, facilities should check with their state environmental agency to determine which regulations apply and the exact standards they must meet. The Air Pollution State Resource Locator is a good starting point for investigating state rules and finding points of contact at state agencies and local air districts.