Update: August 1993
Current Massachusetts Regulatory Limit
MMCL = 0.002 mg/L. ORS has adopted the MCL published by the U.S. EPA as part of the Phase II rule. (56 FR 3526; 1-30-91).
Federal Regulatory Limit
The MCL is set equal to the PQL of 0.002 mg/L.
The MCLG is equal to zero. The MCL for chlordane of 0.002 mg/L was promulgated by the U.S. EPA on January 30, 1991 as part of the Phase II Rule. U.S. EPA has set the MCL at 0.002 mg/L to reduce the risk of cancer or other adverse health effects which have been observed in laboratory animals (Fed. Reg., 1991).
Basis for Criteria
The concentration of 0.002 mg/L may also be calculated, assuming a 70 kg adult drinks 2 L water per day, using the Reference Dose (RfD) presented below (Fed Reg, 1991).
RfD oral = 6 x 10-5 mg/kg/day
UF: 1000 (10 = interspecies; 10 = intraspecies; 10 = lack of a second chronic study)
Fisher 344 rats (80/sex/dose) were fed technical chlordane at dietary levels of 0,1,5, and 25 ppm for 130 weeks. Liver hypertrophy was noted in female rats at a dosage of 0.273 mg/kg/day. A NOAEL of 0.055 mg/kg/day was established based on liver hypertrophy.
Cancer Assessment B2
Based on potential cancer effects there is sufficient animal evidence of cancer (Becker and Sell 1979). Inadequate evidence exists in humans. A cancer potency factor (CPF) of 1.3 (mg/kg/day)-1 was used to calculate an Excess Lifetime Cancer Risk (ELCR) of approximately six in one hundred thousand at the standard of 0.002 mg/L.
PQL: The PQL used as the basis for the MCL is 0.002 mg/L.
U.S. EPA 508 (GC-ECD)
505 (microextraction GC)
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.
Becker, F.F. and S. Sell. 1979. alpha-Fetoprotein levels and hepatic alterations during chemical carcinogenesis in C57BL/6N mice. Cancer Research 39:3491-3494.
Federal Register. January 30, 1991. Part II. Environmental Protection Agency. 40 CFR Parts 141, 142, and 143. National Primary Drinking Water Regulations; Final Rule. (56 FR 3526).
Velsicol Chemical Co. 1983. MRID No. 00138591, 00144313. Available from U.S. EPA. Write to U.S. EPA, Washington, DC 20460.