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Title 40

Displaying title 40, up to date as of 10/08/2026. Title 40 was last amended 10/08/2026.
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§ 63.3491 What are my options for meeting the emission limits?

You must include all coatings and thinners used in all surface coating operations within a subcategory or coating type segment when determining whether the organic HAP emission rate is equal to or less than the applicable emission limit in § 63.3490. To make that determination, you must use at least one of the four compliance options listed in paragraphs (a) through (d) of this section. You may apply any of the compliance options to an individual coating operation or to multiple coating operations within a subcategory or coating type segment as a group. You may use different compliance options for different coating operations or at different times on the same coating operation. However, you may not use different compliance options at the same time on the same coating operation. If you switch between compliance options for any coating operation or group of coating operations, you must document that switch as required by § 63.3512(c), and you must report it in the next semiannual compliance report required in § 63.3511.

(a) Compliant material option. Demonstrate that the organic HAP content of each coating used in the coating operation(s) is less than or equal to the applicable emission limit in § 63.3490, and that each thinner used contains no organic HAP. You must meet all the requirements of §§ 63.3520, 63.3521, and 63.3522 to demonstrate compliance with the emission limit using this option.

(b) Emission rate without add-on controls option. Demonstrate that, based on the coatings and thinners used in the coating operation(s), the organic HAP emission rate for the coating operation(s) is less than or equal to the applicable emission limit in § 63.3490, calculated as a rolling 12-month emission rate and determined on a monthly basis. You must meet all the requirements of §§ 63.3530, 63.3531, and 63.3532 to demonstrate compliance with the emission limit using this option.

(c) Emission rate with add-on controls option. Demonstrate that, based on the coatings and thinners used in the coating operation(s) and the emission reductions achieved by emission capture systems and add-on controls, the organic HAP emission rate for the coating operation(s) is less than or equal to the applicable emission limit in § 63.3490, calculated as a rolling 12-month emission rate and determined on a monthly basis. If you use this compliance option, you must also demonstrate that all emission capture systems and add-on control devices for the coating operation(s) used for purposes of complying with this subpart meet the operating limits required in § 63.3492, except for solvent recovery systems for which you conduct liquid-liquid material balances according to § 63.3541(i), and that you meet the work practice standards required in § 63.3493. You must meet all the requirements of §§ 63.3540 through 63.3547 to demonstrate compliance with the emission limits, operating limits, and work practice standards using this option.

(d) Control efficiency/outlet concentration option. Demonstrate that, based on the emission reductions achieved by emission capture systems and add-on controls, total HAP emissions measured as total hydrocarbon (THC) are reduced by 95 percent or greater for existing sources, or 97 percent or greater for new or reconstructed sources, or that outlet THC emissions are less than or equal to 20 parts per million by volume, dry basis (ppmvd). If you use this compliance option, you must have a capture device that meets EPA Method 204 of 40 CFR part 51, appendix M criteria for a permanent total enclosure (PTE). You must also demonstrate that all emission capture systems and add-on control devices for the coating operation(s) used for purposes of complying with this subpart meet the operating limits required in § 63.3492, and that you meet the work practice standards required in § 63.3493. You must meet all the requirements of §§ 63.3550 through 63.3557 to demonstrate compliance with the emission limits, operating limits, and work practice standards using this option.