StacksVerified U.S. regulatory reference

40 CFR Part 98, Table C-2

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov
Fuel typeDefault CH4 emission factor (kg CH4/mmBtu)Default N2 O emission factor (kg N2 O/mmBtu)
Coal and Coke (All fuel types in Table C-1)1.1 × 10−021.6 × 10−03
Natural Gas11.0 × 10−31.0 × 10−4
Petroleum Products (All fuel types in Table C-1)3.0 × 10−036.0 × 10−04
Fuel Gas3.0 × 10−036.0 × 10−04
Other Fuels—Solid3.2 × 10−024.2 × 10−03
Blast Furnace Gas2.2 × 10−051.0 × 10−04
Coke Oven Gas4.8 × 10−041.0 × 10−04
Biomass Fuels—Solid (All fuel types in Table C-1, except wood and wood residuals)3.2 × 10−024.2 × 10−03
Wood and wood residuals7.2 × 10−033.6 × 10−03
Biomass Fuels—Gaseous (All fuel types in Table C-1)3.2 × 10−036.3 × 10−04
Biomass Fuels—Liquid (All fuel types in Table C-1)1.1 × 10−031.1 × 10−04

Note: Those employing this table are assumed to fall under the IPCC definitions of the “Energy Industry” or “Manufacturing Industries and Construction”. In all fuels except for coal the values for these two categories are identical. For coal combustion, those who fall within the IPCC “Energy Industry” category may employ a value of 1g of CH4/mmBtu.

1 Reporters subject to subpart W of this part may only use the default CH4 emission factor for natural gas-fired combustion units that are not reciprocating internal combustion engines or gas turbines. For natural gas-fired reciprocating internal combustion engines or gas turbines, at facilities subject to subpart W of this part, reporters must use a CH4 emission factor determined in accordance with § 98.233(z)(4).

[78 FR 71952, Nov. 29, 2013, as amended at 81 FR 89252, Dec. 9, 2016; 89 FR 42220, May 14, 2024]