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Title 40

Displaying title 40, up to date as of 6/10/2026. Title 40 was last amended 6/08/2026.
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Table 2 to Subpart LLL of Part 63—1989 Toxic Equivalency Factors (TEFs)

Dioxins/Furans TEFs 1989
2,3,7,8-TCDD 1
1,2,3,7,8-PeCDD 0.5
1,2,3,4,7,8-HxCDD 0.1
1,2,3,6,7,8-HxCDD 0.1
1,2,3,7,8,9-HxCDD 0.1
1,2,3,4,6,7,8-HpCDD 0.01
OCDD 0.001
2,3,7,8-TCDF 0.1
1,2,3,7,8-PeCDF 0.05
2,3,4,7,8-PeCDF 0.5
1,2,3,4,7,8-HxCDF 0.1
1,2,3,6,7,8-HxCDF 0.1
1,2,3,7,8,9-HxCDF 0.1
2,3,4,6,7,8-HxCDF 0.1
1,2,3,4,6,7,8-HpCDF 0.01
1,2,3,4,7,8,9-HpCDF 0.01
OCDF 0.001

[83 FR 35136, July 25, 2018]