What is California Proposition 65? Prop 65 is known as the “Safe Drinking Water Toxics Enforcement Act of 1986”. It says that no one shall introduce into the drinking waters of the state of California any substance that may cause reproductive or carcinogenic toxicity. This legislation, however, has expanded into the consumer product area. Wherefore, dietary supplements, herbal, cosmetic and even home products, etc. have been included within the confines of this piece of legislation.

By law, the governor’s office, on an annual basis, publishes a list of the chemical compounds that are regulated by California Proposition 65. Currently, there are approximately 600+ chemical substances on the list. This list is constantly being updated with standards, additions and delistings of chemical substances.

If a particular product or its ingredients has substances known to be carcinogenic or reproductively toxic, on the Prop 65 list and exceeds the “no significant risk levels” prescribed by law, then one of two things may be required.

  1. A warning label will need to be placed on the product and or advertisement stating “This product contains [substance] a chemical known [to the state of California] to cause birth defects or other reproductive harm”.
  2. The manufacturer, raw ingredient supplier, distributor or retailer may provide documentation as proof that the particular chemical substance is not present or at levels below limits set by California Proposition 65.

Testing procedures were established for the determination of lead levels in calcium products, by litigation, in 1997, by the state of California versus several calcium carbonate manufacturers. The testing protocols were written for inductively coupled plasma – mass spectrometry (ICP-MS). This technique is more suited for this type of analysis because of the complexity of the matrix that calcium and other dietary, herbal or cosmetic substances display. ICP-MS is capable of detecting lower levels of elements than most elemental detection techniques with minimal interference difficulties.

California Proposition 65 is here to stay. It is a very popular piece of legislation having strong support from the California populace and its legislators.

Chemical Solutions Ltd. (CSL) is dedicated to providing trace elemental analysis by ICP-MS. We also recognize that while it is very important to have the latest technology, having you receive your information on time is just as critical.

California Proposition 65 List of Metals


Carcinogen Causing Elements

Target Analyte
Safe Harbor Level (ug/day)
Arsenic (As) 0.06 (inhalation)
10 (except Inhalation)
1000 Fibers/day (inhalation)
Beryllium (Be) 0.1
Cadmium (Cd) 0.05 (inhalation)
Lead (Pb) 15 (oral)
Chromium, Hexavalent (Cr+6)) 0.001 (inhalation)

Reproductive Toxicity Causing Elements

Target Analyte
Safe Harbor Level (ug/day)
Cadmium (Cd) 4.1 (oral)
Lead (Pb) .5

First Priority List

Target Analyte
Mercury Compounds

Second Priority List

Target Analyte
Nickel And Nickel Compounds