Code of Federal Regulations > Title 40 > Chapter I > Part 98 > Subpart C > Appendix - Table C-2 to Subpart C of Part 98—Default CH4 and N2O Emission Factors for Various Types of Fuel

Regulations last checked for updates: Oct 09, 2025

Title 40 - Protection of Environment last revised: Sep 09, 2029

Appendix - Table C-2 to Subpart C of Part 98—Default CH4 and N2O Emission Factors for Various Types of Fuel

Fuel type	Default CH4 emission factor (kg CH4/mmBtu)	Default N2O emission factor (kg N2O/mmBtu)
Coal and Coke (All fuel types in Table C-1)	1.1 × 10−02	1.6 × 10−03
Natural Gas ¹	1.0 × 10− ⁰³	1.0 × 10− ⁰⁴
Petroleum Products (All fuel types in Table C-1)	3.0 × 10−03	6.0 × 10−04
Fuel Gas	3.0 × 10−03	6.0 × 10−04
Other Fuels—Solid	3.2 × 10−02	4.2 × 10−03
Blast Furnace Gas	2.2 × 10−05	1.0 × 10−04
Coke Oven Gas	4.8 × 10−04	1.0 × 10−04
Biomass Fuels—Solid (All fuel types in Table C-1, except wood and wood residuals)	3.2 × 10−02	4.2 × 10−03
Wood and wood residuals	7.2 × 10−03	3.6 × 10−03
Biomass Fuels—Gaseous (All fuel types in Table C-1)	3.2 × 10−03	6.3 × 10−04
Biomass Fuels—Liquid (All fuel types in Table C-1)	1.1 × 10−03	1.1 × 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]

authority: 42 U.S.C. 7401-7671q.

source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.