Update: August 1993
Current Massachusetts Regulatory Limit
MMCL = 0.7 mg/L. ORS has adopted the MCL published by the U.S. EPA as part of the Phase V rule (57 FR 31776: 7-17-92).
Federal Regulatory Limit
The MCL is based on the MCLG of 0.7 mg/L.
Basis for Criteria
The MCLG is derived using the RfD presented below and assuming that a 70 kg adult ingests 2 L/day of drinking water. A relative source contribution factor of 20% is incorporated into the final value.
RfD: 1 x 10-1 mg/kg/day
UF: 100 (10 = interspecies; 10 = intraspecies)
MF: 1 Confidence in RfD: High
Acute exposure to glyphosate for relatively short periods of time at levels above the MCL could result in congestion of the lungs and an increased breathing rate. Chronic lifetime exposure to concentrations above the MCL may produce kidney damage and reproductive effects. In a three-generation rat feeding study, at dose levels of 0, 3, 10 or 30 mg/kg/day, the only compound-related effect noted was tubular dilation of the kidneys in third generation males at the highest dose. A NOAEL of 10 mg/kg/day was identified in this study (55 FR 30370; 7-25-90).
There is some evidence that glyphosate may have the potential to cause cancer from a lifetime exposure at levels above the MCL.
PQL: 0.4 ug/L (57 FR 31776: 7-17-92)
U.S. EPA Method 547
Standard Method 6651
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. (57 FR 31776).