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California Adopts New Rule on Methods of Detection as a Defense in Prop. 65 Enforcement Actions

Author: George G. Misko

The California Office of Environmental Health Hazard Assessment (OEHHA) has adopted a new regulation—Title 22, California Code of Regulations, Section 12900*—allowing a business that conducts testing to rely on the results of those tests as a defense against allegations of violating California's Proposition 65—the Safe Drinking Water and Toxic Enforcement Act of 1986 ("Prop. 65" or the "Act"). The new regulation replaces old Section 12901, which had established a hierarchy of methods considered authoritative in assessing the presence of a listed chemical under Prop. 65.

In addition to providing a "safe harbor" for persons subject to the discharge prohibition and warning requirements of the Act, the new regulation is intended to encourage businesses to test products and environmental releases for the presence of listed chemicals.

Section 12900* does not apply when a listed chemical is detected in a product or an environmental release. In that case, other sections of the California Prop. 65 regulations must be consulted to determine whether the discharge or release contained a significant amount of the chemical, or whether an exposure creates a risk significant enough to require a warning under Prop. 65.


California's Prop. 65 was enacted as a voters' initiative in 1986. The Act includes a prohibition against contaminating sources of drinking water with chemicals known to the state to cause cancer or reproductive harm. It also includes a requirement that businesses provide clear and reasonable warnings before exposing individuals to chemicals known to the state to cause cancer or reproductive harm. Some 800 chemical substances are now included in Prop. 65.

California Health and Safety Code Section 25249.11(c) defines a "significant amount" of a listed chemical as "any detectable amount," other than an amount that poses no significant risk for carcinogens, or would have no observable effect assuming exposure at 1,000 times the level in question with regard to chemicals known to cause reproductive harm. However, Prop. 65 does not specify what analytical test methods must be used to determine whether a discharge, release, or exposure contains a detectable amount of a listed chemical.

Section 12901*, adopted in 1989, was supposed to clarify the meaning of "any detectable amount" and allow regulated industries to rely on analytical test methods and procedures they were already using to comply with other environmental laws. However, litigants and the courts had difficulty interpreting and applying Section 12901, particularly in the context of consumer products exposures. OEHHA attempted to amend Section 12901 to make it conform to the California Evidence Code and case law, but many thought that the proposed amendments did not solve the problem. OEHHA then decided to repeal Section 12901 and, at the same time, undertake a rulemaking process to help find a solution to the problem. Eventually, OEHHA came up with Section 12900 to replace Section 12901.

OEHHA first proposed adopting new Section 12900 in February 2005. The proposed language was modified three times during several comment periods over the course of the last year. The California Office of Administrative Law finally approved the adoption of the regulation in March 2006, and it became effective on April 8, 2006. A summary of the new rule follows.

Methods of Detection and Analysis as a Defense in Enforcement Actions

Under new Section 12900*, no knowing discharge or release and no knowing and intentional exposure occurs if a person, in the course of doing business, otherwise responsible for an alleged release, discharge, or exposure can show all of the following:

(1) that a properly applied method of detection and analysis for the chemical in question has been used at any time within the year prior to notice of an alleged discharge, release, or exposure to the chemical in question;

(2) that this method of detection and analysis was applied to the same matrix, as defined below, in which the discharge, release, or exposure is alleged to have occurred (or to be occurring);

(3) that the method of detection and analysis was conducted by a certified laboratory; and

(4) that all of the reported results show that the chemical in question was not detected.

"Method of detection and analysis" means a specific analytical testing procedure appropriate for detecting a particular chemical in a particular matrix, such as air, water, soil, or food, that is applied for the purpose of detecting the chemical or measuring its concentration. "Matrix" means the component or substrate that contains the chemical in question.

Methods of detection and analysis that may be relied on are those that are required or sanctioned by the U.S. Food and Drug Administration, U.S. Environmental Protection Agency, U.S. Occupational Safety and Health Administration, National Institute of Occupational Safety and Health, U.S. Consumer Product Safety Commission, California Department of Health Services, California Environmental Protection Agency and its constituent boards, departments, or office, an Air District, a Regional Water Quality Control Board, a Certified Unified Program Agency, or other local enforcement agency in California with jurisdiction over the product or activity that is the cause of the alleged discharge, release, or exposure.

If more than one method of detection and analysis exists that meets the criteria set forth above, the person who seeks to rely on the reported results of that method must either use a method required by that person's permit to be used for detecting or measuring the chemical in question in the relevant matrix, or the most sensitive method of detection and analysis that meets the requirements above.

For these purposes, the phrase "required or sanctioned" means that an agency listed above has identified the method of detection and analysis in a permit, regulation, guideline, or other official agency action that specifies or requires the use of that method for purposes of detecting or measuring the concentration of the chemical in question in the relevant matrix. A "permit" includes any document, license, registration, certificate, or other written means of authorization necessary for a business activity.

In any enforcement action for an alleged violation of Section 25249.5 or 25249.6 of the Act, the person using new Section 12900* as an affirmative defense will have the burden of proof on all facts that establish the defense, including the burden of proving that all material protocols and procedures specified by the agency that requires or sanctions the method of detection and analysis applied have been followed.

Nothing in new Section 12900* prevents a plaintiff from proving an alleged discharge, release, or exposure by any admissible evidence, or a defendant from proving the absence of an alleged discharge, release, or exposure by any admissible evidence, except that an alleged discharge, release, or exposure may not be established solely by applying a scientific inference that a listed chemical is present in a particular matrix at one half the limit of detection for the applicable method of detection and analysis. Further, nothing in Section 12900 requires any person to conduct routine tests for discharges, releases, or exposures to listed chemicals that may be subject to Prop. 65.

For more information on the new California provision, click here.

* Effective June 18, 2008, all Proposition 65 regulations were moved from Title 22, sections 12000 to 14000 inclusive, to Title 27, sections 25000 to 27001 inclusive, of the California Code of Regulations (CCR). Click here to see a chart showing the location of each regulation.