Prioritizing Chemicals for Consideration as Carcinogens by the "SQE": Second Round Pilot Random Selection
The Office of Environmental Health Hazard Assessment (OEHHA) is responsible for the implementation of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65; Health and Safety Code Section 25249.5 et seq.). Under the Act, a chemical may be identified as "known to the State to cause cancer" when the state’s qualified experts find it to be clearly shown, through scientifically valid testing according to generally accepted principles, to cause cancer. Chemicals may also be identified through two administrative listing processes (see the DRAFT document Mechanisms for Listing Chemicals Under Proposition 65, May 1996 available on the OEHHA Home Page. The Carcinogen Identification Committee of the OEHHA Science Advisory Board serves as the State’s qualified experts for identifying carcinogens under Proposition 65. The effort described in this notice is directed at prioritizing chemicals for carcinogenicity evaluation by the Carcinogen Identification Committee.
OEHHA has developed a database of chemicals that have been nominated for consideration or evaluated under Proposition 65. The database contains entries on several hundred chemicals. Candidacy is based on information taken from the scientific literature, lists and databases, and on nominations from members of OEHHA’s Science Advisory Board, other state agencies, the scientific community, and the general public. The toxicological information on nominees includes, for example, positive cancer data from animal and human studies, or data from other relevant studies. Chemicals are tracked and the database updated as new information becomes available.
As a pilot, a first round of random selection was conducted in August 1997. The second pilot random selection will be conducted on 100 chemicals (Table 1) which consists of the 52 chemicals remaining from the first round of random selection and 48 additional chemicals selected from the database using the table of random numbers published in the California Regulatory Notice Register (CRNR) on August 15, 1997. [Note: Fifty-five chemicals remained from the first round of random selection conducted in August 1997. On December 5, 1997, three of the 55 chemicals were published in the CRNR in a Notice of Intent to List via the administrative listing mechanism; and therefore are not included in the random selection process. The chemicals were cytembena, methyl carbamate, and nalidixic acid.] These 100 chemicals are those which have completed data sheets available that provide a preview of some of the toxicity information available on the compounds. To maximize the use of staff resources, sixty chemicals will be selected in this second round of random selection. Each of the sixty selected chemicals will receive a screening toxicity evaluation as described in the document entitled Procedure for Prioritizing Candidate Chemicals for Consideration Under Proposition 65 by the "State’s Qualified Experts", May 1997 (available on the OEHHA Home Page). The screening toxicity evaluations are based on a brief review of readily available toxicological information and are reported in a data summary, which includes an assignment of priority status with respect to toxicological concern. Draft data summaries are released for scientific review and public comment. A public workshop will be held during the public comment period to solicit verbal, as well as written comment. Chemicals receiving a final priority ranking of "high" toxicity concern will be considered first by the Carcinogen Identification Committee (CIC). To facilitate the Carcinogen Identification Committee’s consideration, hazard identification documents are prepared that summarize the scientific evidence on the carcinogenicity of the chemical. Initially, hazard identification documents will only be prepared on chemicals with a priority ranking of "high".
For the pilot random selection process, OEHHA developed a series of 500 randomly generated numbers using Microsoft Excel (shown in Table 2 below). OEHHA will insert the 100 alphabetically arranged chemicals shown in Table 1 into Table 2 to determine a numerical reordering of the 100 chemicals. This will result in a "shuffling" of the alphabetical list. The relative position where the alphabetical listing in Table 1 is inserted into the series of random numbers in Table 2 will be based on the sum of the first three Super Lotto numbers drawn on Saturday, March 21, 1998. For purposes of illustration only, if the first three numbers drawn are 3, 27, and 48, the sum will be 78 and the first chemical in Table 1 will be assigned the numerical value of the 78th number (336) in Table 2. The second chemical in Table 1 will have the numerical value of the 79th number (277) in Table 2 and so on. These 100 assigned random numbers, and corresponding chemicals, will be reordered according to increasing value. The lowest 60 numerical values will constitute the sixty chemicals selected in this second pilot random selection. The results of the random selection will be posted on OEHHA’s Home Page on or before March 30, 1998. The remaining 40 chemicals will be part of the pool from which future selections will occur.
OEHHA is committed to an open and public process in the implementation of Proposition 65.
For inquiries on Proposition 65, please call or write to:
the Proposition 65 Office
Office of Environmental Health Hazard Assessment
Post Office Box 4010
Sacramento, CA 95812-4010
FAX (916) 327-1097
(916) 445-6900