Return to Standards Table

CASRN: 7440508

Update: May 2004

Current Massachusetts Regulatory Limit
MMCL = Treatment Technique. Action Level = 1.3 mg/L. ORS has adopted the Action Level published by the U.S. EPA (FR 6/7/91, 56 FR 32112; 7-15-91).

Federal Regulatory Limit
The Action Level for copper is 1.3 mg/L. The Treatment Technique for copper requires public water supply systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the copper Action Level of 1.3 mg/L, water systems must take additional steps (U.S. EPA, 2002). The MCLG for copper is equivalent to the Action Level of 1.3 mg/L.

An action level is different from an MCL. Exceeding the action level for copper triggers one or more of the following options:
(1) replacement of service lines,
(2) corrosion control,
(3) treatment of the source,
(4) public education.

Basis for Criteria
There are no data currently in the RfD development stage of the regulations.

RfD: LOAEL is 5.3 mg/day
UF: 2 MF: 1

Based on a LOAEL of 5.3 mg/day from human clinical case studies in which 5.3 mg was the lowest acute oral dose at which gastrointestinal effects were seen (Chuttani et al, 1965 as cited in Federal Register, 1991). The MCLG and Action Level are derived using the following approach:

5.3 mg/day
2 x 2 L/day = 1.3 mg/L

Critical Effects
The Action Level is based on a Lowest Observed Adverse Effect Level (LOAEL) of 5.3 mg/L identified from a clinical study of humans exposed to copper. Humans given 5.3 mg of copper orally as an acute dose demonstrated gastrointestinal effects.

Cancer Assessment: 
Data Are Inadequate for the Assessment of Human Carcinogenic Potential/D

Copper is currently classified as a Group D, not classifiable as to human carcinogenicity based on inadequate animal data and equivocal mutagenicity data.

Naturally occurring metal

Analytical Information
Method dependent

Analytical Methods: 
U.S. EPA 220.2 GFAA
220.1 DAAA
200.7 ICP
200.8 ICP/MS
200.9 AA/Platform Furnace.2

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

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

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 Please note that the information in IRIS may differ from that used in the derivation process as published in the Federal Register notice.

Chuttani, H.K. et al. Acute Copper Sulfate Poisoning. American Journal of Medicine. Vol. 39. (November 1965). pp 849-854.

Federal Register. Friday, June 7, 1991. Vol. 56, No. 110. Maximum Contaminant Level Goals and National Primary Drinking Water Regulations for Lead and Copper; Final Rule.

U.S. EPA (U.S. Environmental Protection Agency). July 2002. List of Contaminants and Their MCLs. EPA 816-F-02-013.