Regulations last checked for updates: Nov 22, 2024

Title 40 - Protection of Environment last revised: Nov 20, 2024
Appendix - Table 4 to Subpart DDDD of Part 60—Model Rule—Toxic Equivalency Factors
Dioxin/furan isomer Toxic
equivalency
factor
2,3,7,8-tetrachlorinated dibenzo-p-dioxin1
1,2,3,7,8-pentachlorinated dibenzo-p-dioxin0.5
1,2,3,4,7,8-hexachlorinated dibenzo-p-dioxin0.1
1,2,3,7,8,9-hexachlorinated dibenzo-p-dioxin0.1
1,2,3,6,7,8-hexachlorinated dibenzo-p-dioxin0.1
1,2,3,4,6,7,8-heptachlorinated dibenzo-p-dioxin0.01
octachlorinated dibenzo-p-dioxin0.001
2,3,7,8-tetrachlorinated dibenzofuran0.1
2,3,4,7,8-pentachlorinated dibenzofuran0.5
1,2,3,7,8-pentachlorinated dibenzofuran0.05
1,2,3,4,7,8-hexachlorinated dibenzofuran0.1
1,2,3,6,7,8-hexachlorinated dibenzofuran0.1
1,2,3,7,8,9-hexachlorinated dibenzofuran0.1
2,3,4,6,7,8-hexachlorinated dibenzofuran0.1
1,2,3,4,6,7,8-heptachlorinated dibenzofuran0.01
1,2,3,4,7,8,9-heptachlorinated dibenzofuran0.01
octachlorinated dibenzofuran0.001
authority: 42 U.S.C. 7401
source: 36 FR 24877, Dec. 23, 1971, unless otherwise noted.