Code of Federal Regulations > Title 40 > Chapter I > Part 63 > Subpart DDDD > Appendix - Table 1B to Subpart DDDD of Part 63—Add-on Control Systems Compliance Options

Regulations last checked for updates: Feb 20, 2025

Title 40 - Protection of Environment last revised: Nov 20, 2025

Appendix - Table 1B to Subpart DDDD of Part 63—Add-on Control Systems Compliance Options

For each of the following process units . . .	You must comply with one of the following six compliance options by using an emissions control system . . .
Fiberboard mat dryer heated zones (at new affected sources only); green rotary dryers; hardboard ovens; press predryers (at new affected sources only); pressurized refiners; primary tube dryers; secondary tube dryers; reconstituted wood product board coolers (at new affected sources only); reconstituted wood product presses; softwood veneer dryer heated zones; rotary strand dryers; conveyor strand dryer zone one (at existing affected sources); and conveyor strand dryer zones one and two (at new affected sources)	(1) Reduce emissions of total HAP, measured as THC (as carbon) ^a, by 90 percent; or (2) Limit emissions of total HAP, measured as THC (as carbon) ^a, to 20 ppmvd; or (3) Reduce methanol emissions by 90 percent; or (4) Limit methanol emissions to less than or equal to 1 ppmvd if uncontrolled methanol emissions entering the control device are greater than or equal to 10 ppmvd; or (5) Reduce formaldehyde emissions by 90 percent; or (6) Limit formaldehyde emissions to less than or equal to 1 ppmvd if uncontrolled formaldehyde emissions entering the control device are greater than or equal to 10 ppmvd.

For each of the following process units . . .

You must comply with one of the following six compliance options by using an emissions control system . . .

Fiberboard mat dryer heated zones (at new affected sources only); green rotary dryers; hardboard ovens; press predryers (at new affected sources only); pressurized refiners; primary tube dryers; secondary tube dryers; reconstituted wood product board coolers (at new affected sources only); reconstituted wood product presses; softwood veneer dryer heated zones; rotary strand dryers; conveyor strand dryer zone one (at existing affected sources); and conveyor strand dryer zones one and two (at new affected sources)

(1) Reduce emissions of total HAP, measured as THC (as carbon) ^a, by 90 percent; or
(2) Limit emissions of total HAP, measured as THC (as carbon) ^a, to 20 ppmvd; or
(3) Reduce methanol emissions by 90 percent; or
(4) Limit methanol emissions to less than or equal to 1 ppmvd if uncontrolled methanol emissions entering the control device are greater than or equal to 10 ppmvd; or
(5) Reduce formaldehyde emissions by 90 percent; or
(6) Limit formaldehyde emissions to less than or equal to 1 ppmvd if uncontrolled formaldehyde emissions entering the control device are greater than or equal to 10 ppmvd.

^a You may choose to subtract methane from THC as carbon measurements.

authority: 42 U.S.C. 7401

source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.