Code of Federal Regulations > Title 40 > Chapter I > Part 63 > Subpart DDDD > Appendix - Table 1C to Subpart DDDD of Part 63—Compliance Options Applicable On and After July 6, 2026

Regulations last checked for updates: Jul 11, 2026

Title 40 - Protection of Environment last revised: Aug 11, 2026

Appendix - Table 1C to Subpart DDDD of Part 63—Compliance Options Applicable On and After July 6, 2026

Table 1C to Subpart DDDD of Part 63—Compliance Options Applicable On and After July 6, 2026

If you operate a(n) . . .	For process units at an affected source that commenced construction or reconstruction on or before May 18, 2023, you must comply with the following compliance options ¹ on and after July 6, 2029 . . .	For process units at an affected source that commenced construction or reconstruction after May 18, 2023, you must comply with the following compliance options ¹ beginning on July 6, 2026, or upon initial startup, whichever is later . . .
Fiberboard mat dryer heated zones at an affected source that commenced construction or reconstruction on or before January 9, 2003 ²	4.9E-02 lb total HAP/MSF 1/8″ or 2.0E-01 lb total HAP/MSF 1/2″	See footnote “2”.
Press predryer at an affected source that commenced construction or reconstruction on or before January 9, 2003 ²	8.0E-02 lb total HAP/MSF 1/8″ or 3.2E-01 lb total HAP/MSF 1/2″	See footnote “2”.
Post-dryer atmospheric refiner	4.1E-03 lb total HAP/ODT or 8.5E-01 ppmvd total HAP	3.3E-03 lb total HAP/ODT or 6.5E-01 ppmvd total HAP.
Multipurpose atmospheric refiner	1.2E-01 lb total HAP/ODT or 15 ppmvd total HAP	2.4E-03 lb total HAP/ODT or 3.3 ppmvd total HAP.
Reconstituted wood product press producing OSB using MDI resin	2.5E-04 lb MDI/MSF 3/4″ (1.3E-04 lb/MSF 3/8″) or 2.7E-02 mg MDI/dscm	2.5E-04 lb MDI/MSF 3/4″ (1.3E-04 lb/MSF 3/8″) or 2.7E-02 mg MDI/dscm.
Reconstituted wood product press producing particleboard or MDF using MDI resin	8.4E-04 lb MDI/MSF 3/4″ or 2.0E-01 mg MDI/dscm	2.3E-04 lb MDI/MSF 3/4″ or 2.7E-02 mg MDI/dscm.
Primary tube dryer blow-line blending MDI resin, or primary tube dryer blow-line blending MDI resin co-controlled with a reconstituted wood products press using MDI resin	1.7E-02 lb MDI/ODT or 6.8E-01 mg MDI/dscm	1.7E-02 lb MDI/ODT or 6.8E-01 mg MDI/dscm.
Miscellaneous coating operation for applying MDI moisture sealant to the surface of an engineered wood product	1.9E-03 lb MDI emitted/lb sealant applied or 1.4E-05 lb MDI per square foot of surface area coated	1.9E-03 lb MDI emitted/lb sealant applied or 1.4E-05 lb MDI per square foot of surface area coated.

¹ Total HAP, as defined in § 63.2292, includes acetaldehyde, acrolein, formaldehyde, methanol, phenol, and propionaldehyde. MDI is 4,4′-Diphenylmethane Diisocyanate (CAS 101-68-8). ug = micrograms; mg = milligrams; dscm = micrograms per dry standard meter; kPa = kilopascals; psia = pounds per square inch absolute; lb/ODT = pounds per oven-dried ton; lb/MSF = pounds per thousand square feet with a specified thickness basis (inches). Section 63.2262(j) shows how to convert from one thickness basis to another.

² Fiberboard mat dryer (heated zones) or press predryers at an affected source that commenced construction or reconstruction after January 9, 2003, must be in compliance with the compliance options in table 1A or 1B to this subpart beginning on September 28, 2004, or upon initial startup, whichever is later.

[91 FR 41451, July 6, 2026]

authority: 42 U.S.C. 7401

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