---
kind: "section"
citation: "40 C.F.R. § 60.6680"
title: "40"
number: "60.6680"
heading: "What equations must I use?"
url: "https://uscodex.org/cfr/40/60.6680"
---

# §60.6680. What equations must I use?

- (a) **Concentration correction to 7 percent oxygen.** Correct any pollutant concentration to 7 percent oxygen using equation 1 of this section:
- (b) **Quarterly carbon usage.** If you use activated carbon to comply with the dioxins/furans or mercury limits, calculate the required quarterly usage of carbon using equation 2 of this section for facility basis or equation 3 of this section for unit basis:
  - (1) **Plant basis.**
  - (2) **Unit basis.**
- (c) **Percent Reduction.** If you opt to comply with the alternative percent reduction standards for hydrogen chloride, mercury or sulfur dioxide, use the following equation to calculate the percent reduction:

## Notes

### Source

Source: 91 FR 11860, Mar. 10, 2026, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 36 FR 24877, Dec. 23, 1971, unless otherwise noted.