ALDICARB SULFOXIDE 
Update: March 1993
Current Massachusetts Regulatory Limit
The ORSGL = 0.004 mg/L. ORS has adopted the MCL for aldicarb sulfoxide originally published by the U.S. EPA under the Phase II Rule (56 FR 3526; 56 FR 30266) as an ORSGL.
Federal Regulatory Limit
The MCL for aldicarb sulfoxide is set at the PQL of 0.002 mg/L. Although U.S. EPA considers aldicarb sulfoxide a regulated contaminant, its MCL has been stayed, meaning that the effective date for these standards was postponed (57 FR 22178). Currently, there is no new effective date for these regulations.
Basis for Criteria
U.S. EPA considered several factors in determining an MCL for aldicarb sulfoxide, including: 1) the effectiveness of the best available technology (BAT) (granulated active charcoal) in removing aldicarb sulfoxide to levels at or below the proposed MCL of 0.002 mg/L; 2) the feasibility (including costs) of applying BAT for large systems; and 3) the PQL. U.S. EPA concluded by setting the MCL for aldicarb sulfoxide at the PQL of 0.002 mg/L, which it considers the lowest level feasible.
The principal toxic effect of aldicarb and its sulfoxide and sulfone metabolites is cholinesterase inhibition as measured in plasma, erythrocyte and brain (50 FR 46936).
Cancer Assessment D
Aldicarb sulfoxide has been identified in U.S. EPAâ€™s Group D, based upon inadequate human evidence of carcinogenicity.
PQL: 0.004 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. November 13, 1985. Part IV. Environmental Protection Agency. 40 CFR Part 141. National Primary Drinking Water Regulations: Synthetic Organic Chemicals, Inorganic Chemicals and Microorganisms; Proposed Rule. (50 FR 46936).
Federal Register. January 30, 1991. Part III. Environmental Protection Agency. 40 CFR Parts 141 and 142. National Primary Drinking Water Regulations; Proposed Rule. (56 FR 3600).
Federal Register. July 1, 1991. Part XII. Environmental Protection Agency. 40 CFR Parts 141, 142, and 143. National Primary Drinking Water Regulations; Final Rule. (56 FR 30266).
Federal Register. May 27, 1992. Drinking Water; National Primary Drinking Water Regulations: Aldicarb, Aldicarb Sulfoxide, and Aldicarb Sulfone. (57 FR 22178).
Union Carbide Agricultural Products Company. 1987. MRID No. 40259901. Available from U.S. EPA. Write to: FOI, EPA, Washington, DC 20460.
 The MCLs for aldicarb, aldicarb sulfone and aldicarb sulfoxide have been stayed.