Update: March 1989
Current Massachusetts Regulatory Limit
MMCL = 0.005 mg/L. ORS has adopted the MCL published by U.S. EPA in the Phase I rule (52 FR 25690; 7/8/87).
Federal Regulatory Limit
The MCL for 1,2-dichloroethane is based on its detection limit of 0.005 mg/L. The MCLG is zero. This value was promulgated as part of the National Primary Drinking Water Regulations: Synthetic Organic Chemicals; Monitoring for Unregulated Contaminants; Final Rule on July 8, 1987 (FR25690).
Basis for Criteria
An MCLG of zero is assigned for 1,2-dichloroethane based on the evidence for carcinogenic potential. The MCL is based on the 1,2-dichloroethane PQL.
Acute exposure to 1,2-dichloroethane for relatively short periods of time at levels above the MCL may produce effects on the central nervous system, lung, kidney, liver, circulatory system and gastrointestinal tract. There is some evidence indicating that chronic exposure to 1,2-dichloroethane at concentrations above the MCL may cause cancer.
Hemangiosarcomas were produced in male Osborne Mendel rats exposed to 1,2-dichoroethane via gavage.
U.S. EPA has classified 1,2-dichloroethane as a B2 (probable) human carcinogen. The oral cancer slope factor of 9.1x 10-2(mg/kg/day)-1 was issued on 1/1/91.
PQL: The PQL used as the basis for the MMCL is 0.005 mg/L.
PQLs and analytical methods may have been updated since this guidance value was last revised. Updated analytical methods for drinking water and their associated PQLs may be found at http://www.epa.gov/safewater/methods/methods.html
Other Regulatory Data
Any Health Advisories, Reference Doses (RfDs), cancer assessments or Cancer Potency Factors (CPFs) referenced in this document pertain to the derivation of the current guidance value. Updated information may be obtained from the following sources:
Health Advisories - The U.S. EPA provides guidance for shorter-term exposures for chemicals based on their non-cancer effects. Current health advisories may be more current than those used to derive MCLs and may be found at http://www.epa.gov/waterscience/drinking/standards/dwstandards.pdf
RfDs, cancer assessments and CPFs - For specific information pertaining to derivation of drinking water criteria, consult the Federal Register notice that announces the availability of the most current guidance for that chemical. In addition, information on other current RfDs and CPFs as well as cancer assessments for specific chemicals may be found in the U.S. EPA Integrated Risk Information System (IRIS) at http://www.epa.gov/iris/. Please note that the information in IRIS may differ from that used in the derivation process as published in the Federal Register notice.
Federal Register. July 8, 1987. Part II. Environmental Protection Agency. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations-Synthetic Organic Chemicals; Monitoring for Unregulated Contaminants; Final Rule. (52 FR 25690).