PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8-; (HeptaCDD, 1,2,3,4,6,7,8-) | 35822-46-9 | 2811 |
14.02
3.09
3.08
3.02
3.10
10.00
5.10
|
|||||||||
| Formula | Synonyms | |||||||||||
| C12HCl7O2 | 1,2,3,4,6,7,8-HEPTACHLORODIBENZO-P-DIOXIN, 1,2,3,4,6,7,8-HCDD, 1,2,3,4,6,7,8-HEPTACHLORODIBENZO(B,E)(1,4)DIOXIN, 1,2,3,4,6,7,8-HEPTACHLORODIBENZO-PARA-DIOXIN, 1,2,3,4,6,7,8-HEPTACHLORODIBENZODIOXIN, 1,2,3,4,6,7,8-HEPTACHLORODIBENZO[1,4]DIOXIN, 1,2,3,4,6,7,8-HEPTACHLORODIBENZO[B,E][1,4]DIOXIN, HEPTACHLORODIBENZO-P-DIOXIN | |||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 425.28 | S |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.013 | 0.14 | 0.85 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.00075 | 0.0080 | 0.049 |
Technical Basis
A review of available sources identified that 1,2,3,4,6,7,8-HeptaCDD is classified as a dioxin. Since the late 1980s, the Environmental Protection Agency (EPA) has implemented a Toxicity Equivalency Factor (TEF) to evaluate the acute toxicity of dioxin and DLCs relative to a reference chemical (2,3,7,8-tetrachlorodibenzo-p-dioxin, CASRN: 1746-01-6), which can be applied to scale these chemicals according to the following equation:
〖TEEL〗_(dioxin or DLC)=〖TEEL〗_(2,3,7,8-TCDD)/〖TEF〗_(dioxin or DLC)
The TEF for 1,2,3,4,6,7,8-HeptaCDD is 0.01. Use of this non-standard TEEL derivation requires additional review and approval according to Sections 4.2 and 4.3, recorded in a deviation memo.
TEEL-1 = TEEL-12,3,7,8-TCDD/ TEF
TEEL-2 = TEEL-22,3,7,8-TCDD/ TEF
TEEL-3 = TEEL-32,3,7,8-TCDD/ TEF
This review generated TEEL values consistent with those in Rev. 29A.
〖TEEL〗_(dioxin or DLC)=〖TEEL〗_(2,3,7,8-TCDD)/〖TEF〗_(dioxin or DLC)
The TEF for 1,2,3,4,6,7,8-HeptaCDD is 0.01. Use of this non-standard TEEL derivation requires additional review and approval according to Sections 4.2 and 4.3, recorded in a deviation memo.
TEEL-1 = TEEL-12,3,7,8-TCDD/ TEF
TEEL-2 = TEEL-22,3,7,8-TCDD/ TEF
TEEL-3 = TEEL-32,3,7,8-TCDD/ TEF
This review generated TEEL values consistent with those in Rev. 29A.
References
2,3,7,8-TCDD TEELs, available at https://edms3.energy.gov/pac/search/detail/1140
Agency for Toxic Substances and Disease Registry. 2022. "ATSDR Office of Community Health Hazard Assessment Toxic Equivalents Guidance for Dioxin and Dioxin-like Compounds." Toxic Equivalents Guidance for Dioxin and Dioxin-like Compounds, April 15: 1-28. Accessed July 17, 2023. https://www.atsdr.cdc.gov/pha-guidance/resources/ATSDR-TEQ-Guidance-Dioxin-and-Dioxin-like-Compounds-508.pdf .
U.S. Environmental Protection Agency. 2023. Dioxin and Dioxin-Like Compounds Toxic Equivalency Information. March 11. Accessed 1 12, 2024. https://www.epa.gov/toxics-release-inventory-tri-program/dioxin-and-dioxin-compounds-toxic-equivalency-information.
U.S. Environmental Protection Agency. 2010. "Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk Assessments of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds." Risk Assessment Forum. Washington, DC. Accessed July 17, 2023. https://rais.ornl.gov/documents/dioxin_tef.pdf