eCFR.io
Daily eCFR

Table 2 to Subpart DDD of Part 63—Emissions Limits and Compliance Dates

Emissions Limits and Compliance Dates

  1. CFR
  2. ›
  3. Title 40
  4. ›
  5. Chapter I
  6. ›
  7. Part 63
  8. ›
  9. Subpart DDD
  10. ›
  11. Subject Group Other Requirements and Information
  12. ›
  13. Appendix Table 2 to Subpart DDD of Part 63
CorpusDaily eCFR
Displayed edition2026-04-27
Last updated2026-04-27

Table 2 to Subpart DDD of Part 63—Emissions Limits and Compliance Dates

If your source is a:And you commenced construction:Your emission limits are: 1And you must comply by: 2
1. CupolaOn or before May 8, 19970.10 lb PM per ton of meltJune 2, 2002.
2. CupolaAfter May 8, 19970.10 lb PM per ton of meltJune 1, 1999.
3. CupolaOn or before May 8, 1997a. 0.10 lb carbon monoxide (CO) per ton of melt,3 or

b. Reduction of uncontrolled CO by at least 99 percent 3		June 2, 2002.
4. CupolaAfter May 8, 1997 but on or before November 25, 2011a. 0.10 lb CO per ton of melt,3 or

b. Reduction of uncontrolled CO by at least 99 percent.3		June 1, 1999.
5. Closed-top cupolaOn or before November 25, 20113.4 lb of carbonyl sulfide (COS) per ton meltJuly 30, 2018.
6. Closed-top cupolaAfter November 25, 20110.062 lb of COS per ton meltJuly 29, 2015.4
7. Open-top cupolaOn or before November 25, 20116.8 lb of COS per ton meltJuly 30, 2018.
8. Open-top cupolaAfter November 25, 20113.2 lb of COS per ton meltJuly 29, 2015.4
9. Cupola using slag as a raw materialOn or before November 25, 20110.16 lb of hydrogen fluoride (HF) per ton melt

0.44 lb of hydrogen chloride (HCl) per ton melt.		July 30, 2018.
10. Cupola using slag as a raw materialAfter November 25, 20110.015 lb of HF per ton melt

0.012 lb of HCl per ton melt.		July 29, 2015.4
11. Cupola not using slag as a raw materialOn or before November 25, 20110.13 lb of HF per ton melt

0.43 lb of HCl per ton melt.		July 30, 2018.
12. Cupola not using slag as a raw materialAfter November 25, 20110.018 lb of HF per ton melt

0.015 lb of HCl per ton melt.		July 29, 2015.4
17. Curing ovenOn or before May 8, 1997a. 0.06 lb of formaldehyde per ton of melt,3 or

b. Reduction of uncontrolled formaldehyde by at least 80 percent.3		June 2, 2002.
18. Curing ovenAfter May 8, 1997 but before November 25, 2011a. 0.06 lb of formaldehyde per ton of melt,3 or

b. Reduction of uncontrolled formaldehyde by at least 80 percent.3		June 1, 1999.
19. Combined drum collection/curing operationOn or before November 25, 20110.17 lb of formaldehyde per ton of melt

0.28 lb of methanol per ton melt.

0.85 lb of phenol per ton melt.		July 30, 2018.
20. Combined drum collection/curing operationAfter November 25, 20110.17 lb of formaldehyde per ton of melt

0.28 lb of methanol per ton melt.

0.85 lb of phenol per ton melt.		July 29, 2015.4
21. Combined horizontal collection/curing operationOn or before November 25, 20110.63 lb of formaldehyde per ton of melt

0.049 lb of methanol per ton melt.

0.12 lb of phenol per ton melt.		July 30, 2018.
22. Combined horizontal collection/curing operationAfter November 25, 20110.63 lb of formaldehyde per ton of melt

0.049 lb of methanol per ton melt.

0.12 lb of phenol per ton melt.		July 29, 2015.4
23. Combined vertical collection/curing operationOn or before November 25, 20112.4 lb of formaldehyde per ton melt

0.92 lb of methanol per ton melt.

0.71 lb of phenol per ton melt.		July 30, 2018.
24. Combined vertical collection/curing operationAfter November 25, 20112.4 lb of formaldehyde per ton melt

0.92 lb of methanol per ton melt.

0.71 lb of phenol per ton melt.		July 29, 2015.4
1 The numeric emissions limits do not apply during startup and shutdown.
2 Existing sources must demonstrate compliance by the compliance dates specified in this table. New sources have 180 days after the applicable compliance date to demonstrate compliance.
3 This emissions limit does not apply after July 30, 2018.
4 Or upon initial startup, whichever is later.

[80 FR 45333, July 29, 2015]