Update: August 1993
Current Massachusetts Regulatory Limit
MMCL = 0.006 mg/L. ORS has adopted the MCL published by the U.S. EPA.
Federal Regulatory Limit
The MCL is equal to the MCLG of 0.006 mg/L. (57 FR 31776 (7-17-92)).
Basis for Criteria
The MCLG is derived based on the RfD presented below and assumes that a 70 kg adult ingests 2 L/day of water. The MCLG assumes a relative source contribution factor of 40%.
RfD: 4 x 10-4 mg/kg/day
UF: 1000 (10 = intraspecies; 10 = interspecies; 10 = LOAEL to NOAEL)
MF: 1 Confidence in RfD: Low
The MCL has also been set at 6 ppb because U.S. EPA believes, given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water.
In a lifetime oral exposure study in rats, antimony produced decreased longevity, changes in blood cholesterol and glucose levels. A LOAEL of 0.43 mg/kg/day was identified from this study (Schroeder et. al., 1970) (55 FR 30370 (7-25-90).
Cancer Assessment D
U.S. EPA Methods: 200.8 (ICP-MS); 200.9 (AA)
Standard Methods: 3113B
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 25, 1990. Part II. Environmental Protection Agency. 40 CFR Part 141 et al. National Primary and Secondary Drinking Water Regulations; Synthetic Organic Chemicals and Inorganic Chemicals; Proposed Rule. (55 FR 30370).
Federal Register. July 17, 1992. Part III. Environmental Protection Agency. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations; Synthetic Organic Chemicals and Inorganic Chemicals; Final Rule.
Schroeder, H.A., M. Mitchner and A.P. Nasor. 1970. Zirconium, Niobium, Antimony, Vanadium and lead in rats: Life term Studies J. Nutr. 100 59-68.