Category (section) Status Last Revised 2,3,7,8-Tetrachlorodibenzo-pdioxin Source Documents• 2,3,7,8-Tetrachlorodibenzo-pdioxin Summary• 2,3,7,8-Tetrachlorodibenzo-pdioxin Support Documents Revision History Date Section Description 02/17/2012 I.A. RfD added • See IRIS Summary for complete revision history.

Critical Effect Point of Departure*

You are here: EPA Home Research Environmental Assessment IRIS Home 2,3,7,8-Tetrachlorodibenzop-dioxin Quickview (CASRN 1746-01-6) 

# 2,3,7,8-Tetrachlorodibenzo-p-dioxin Quickview (CASRN 1746-01-6)
Health assessment information on a chemical substance is included in IRIS only after a comprehensive review of toxicity data by U.S. EPA health scientists from several Program Offices, Regional Offices, and the Office of Research and Development. Disclaimer: This QuickView represents a snapshot of key information. We suggest that you read the IRIS Summary to put this information into complete context. For definitions of terms in the IRIS Web site,refer to the IRIS Glossary. Status of Data for 2,3,7,8-Tetrachlorodibenzo-p-dioxin File First On-Line: 02/17/2012; Last Significant Revision: 02/17/2012
Oral RfD Assessment Yes 02/17/2012 Inhalation RfC Assessment No Carcinogenicity Assessment Message 02/17/2012 Synonyms • 1746-01-6• 2,3,7,8-tetrachlorodibenzop-dixoin • TCDD • Dibenzo(b,e)(1,4)dioxin, 2,3,7,8-tetrachloro- • Dibenzo-p-dioxin, 2,3,7,8-tetrachloro- • 2,3,7,8-TCDD • Tetrachlorodibenzodioxin • 2,3,7,8-Tetrachlorodibenzo(b,e)(1,4) dioxin • 2,3,7,8-Tetrachlorodibenzo-1,4-dioxin • Tetradioxin • Dioxin

Chronic Health Hazard Assessments for Noncarcinogenic Effects Reference Dose for Chronic Oral Exposure (RfD) UF R F D Decreased sperm count and motility in men exposed to TCDD as boys / Increased TSH in neonates LOAEL (ADJ): 2 x10 -8 mg/kg-day 30 7 x10 -10 mg/kg-day LOAEL (ADJ): 2 x10 -8 mg/kg-day 30 7 x10 -10 mg/kg-day *The Point of Departure listed serves as a basis from which the Oral RfD was derived. See Discussion of Conversion Factors and Assumptions for more details. • Principal and Supporting Studies (Oral RfD) • Epidemiologic cohort study, Mocarelli et al., (2008) / Baccarelli et al., (2008) • Confidence in the Oral RfD • Study -- High • Database -- High • RfD -- High Reference Concentration for Chronic Inhalation Exposure (RfC) Not Assessed under the IRIS Program. Carcinogenicity Assessment for Lifetime Exposure



# Integrated Risk Information System (IRIS) Page 1 of 2 2,3,7,8

- Tetrachlorodibenzo

-p - dioxin Quickview (CASRN 1746

- 01

- 6)|IRIS|USEPA

4/4/2016 https://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_n

...• Weight-of-Evidence Characterization • Assessment underway at the time of the last significant revision. Quantitative Estimate of Carcinogenic Riskfrom Oral Exposure • Assessment underway at the time of the last significant revision. Quantitative Estimate of Carcinogenic Riskfrom Inhalation Exposure • Assessment underway at the time of the last significant revision. 

# Page 2 of 2 2,3,7,8

- Tetrachlorodibenzo

-p - dioxin Quickview (CASRN 1746

- 01

- 6)|IRIS|USEPA

4/4/2016 https://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showQuickView&substance_n

...