Agency RfD Work Group Review: 01/22/86 

 Verification Date: 01/22/86 



I A.7. EPA CONTACTS (ORAL RfD) 



Michael L. Dourson / ORD -- (513)569-7544 / FTS 684-7544 

 Christopher T. DeRosa / ORD -- (513)569-7534 / FTS 684-7534 



I.B. REFERENCE DOSE FOR CHRONIC INHALATION EX- 

 POSURE (RfDi) 



Not available at this time 



IL CARCINOGENICITY ASSESSMENT FOR LIFETIME EX- 

 POSURE 



Substance Name - gamma-Hexachlorocyclohexane (gamma-HCH) 

 Primary Synonym - Lindane 

 CASRN - 58-89-9 



This chemical is among those substances evaluated by the U.S. EPA 

 for evidence of human carcinogenic potential. This does not imply that 

 this chemical is necessarily a carcinogen. The evaluation for this 

 chemical is under review by an inter-ofnce Agency work group. A risk 

 assessment summary will be included on IRIS when the review has been 

 completed. 



III. HEALTH HAZARD ASSESSMENTS FOR VARIED EX- 

 POSURE DURATIONS 



Substance Name - gamma-Hexachlorocyclohexane (gamma-HCH) 

 Primary Synonym - Lindane 

 CASRN - 58-89-9 

 Last Revised - 03/01/88 



IIIA. DRINKING WATER HEALTH ADVISORIES 



The Office of Drinking Water provides Drinking Water Health Ad- 

 visories (HAs) as technical guidance for the protection of public 

 health. HAs are not enforceable Federal standards. HAs are con- 

 centrations of a substance in drinking water estimated to have negli- 

 gible deleterious effects in humans, when ingested, for a specified 

 period of time. Exposure to the substance from other media is con- 

 sidered only in the derivation of the lifetime HA. Given the absence 

 of chemical-specific data, the assumed fraction of total intake from 

 drinking water is 10% for inorganic contaminants and 20% for organic 

 contaminants. The lifetime HA is calculated from the Drinking Water 

 Equivalent Level (DWEL) which, in turn, is based on the Oral Chronic 

 Reference Dose. Lifetime HAs are not derived for compounds which 

 are potentially carcinogenic for humans because of the difference in 

 assumptions concerning toxic threshold for carcinogenic and noncar- 

 cinogenic effects. A more detailed description of the assumptions and 

 methods used in the derivation of HAs is provided in Background 

 Document 3 in Service Code 5. 



IIIA.L ONE-DAY HEALTH ADVISORY FOR A CHILD 



Appropriate data for calculating a One-day HA are not available. It 

 is recommended that the Ten-day HA of 1.2 mg/L (rounded to 1 mg/L) 

 be used as the One-day HA. 



IIIA2. TEN-DAY HEALTH ADVISORY FOR A CHILD 



Ten-day HA - 1.2E -I- mg/L 



