Code of Federal Regulations > Title 40 > Chapter I > Part 63 > Subpart DDDD > Appendix - Table 3 to Subpart DDDD of Part 63

Regulations last checked for updates: Feb 20, 2025

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

Appendix - Table 3 to Subpart DDDD of Part 63—Work Practice Requirements

For the following process units at existing or new affected sources . . .	You must . . .
(1) Dry rotary dryers	Process furnish with a 24-hour block average inlet moisture content of less than or equal to 30 percent (by weight, dry basis); AND operate with a 24-hour block average inlet dryer temperature of less than or equal to 600 °F.
(2) Hardwood veneer dryers	Process less than 30 volume percent softwood species on an annual basis.
(3) Softwood veneer dryers	Minimize fugitive emissions from the dryer doors through (proper maintenance procedures) and the green end of the dryers (through proper balancing of the heated zone exhausts).
(4) Veneer redryers	Process veneer that has been previously dried, such that the 24-hour block average inlet moisture content of the veneer is less than or equal to 25 percent (by weight, dry basis).
(5) Group 1 miscellaneous coating operations	Use non-HAP coatings as defined in § 63.2292.
(6) Process units and control systems undergoing safety-related shutdown on and after August 13, 2021 except as noted in footnote “1” to this table	Follow documented site-specific procedures such as use of automated controls or other measures that you have developed to protect workers and equipment to ensure that the flow of raw materials (such as furnish or resin) and fuel or process heat (as applicable) ceases and that material is removed from the process unit(s) as expeditiously as possible given the system design to reduce air emissions.
(7) Pressurized refiners undergoing startup or shutdown on and after August 13, 2021 except as noted in footnote “1” to this table	Route exhaust gases from the pressurized refiner to its dryer control system no later than 15 minutes after wood is fed to the pressurized refiner during startup. Stop wood flow into the pressurized refiner no more than 15 minutes after wood fiber and exhaust gases from the pressurized refiner stop being routed to the dryer during shutdown.
(8) Direct-fired softwood veneer dryers undergoing startup or shutdown of gas-fired burners on and after August 13, 2021 except as noted in footnote “1” to this table	Cease feeding green veneer into the softwood veneer dryer and minimize the amount of time direct gas-fired softwood veneer dryers are vented to the atmosphere due to the conditions described in § 63.2250(d).

¹ New or reconstructed affected sources that commenced construction or reconstruction after September 6, 2019 must comply with this requirement beginning on August 13, 2020 or upon initial startup, whichever is later.

[85 FR 49461, Aug. 13, 2020]

authority: 42 U.S.C. 7401

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