Evaluation Report for School Site Risk Assessment: Malathion
Evaluation Report for School Site Risk Assessment: Malathion
The Office of Environmental Health Hazard Assessment (OEHHA) is required under Health and Safety Code Section 901(g) (Section) to identify those chemical contaminants commonly found at school sites and determined by OEHHA to be of greatest concern based on child-specific physiological sensitivities. The Section also requires OEHHA to evaluate and publish, as appropriate, numerical health guidance values, such as child-specific reference doses (chRDs), for these chemical contaminants.
OEHHA has identified malathion as a contaminant of concern pursuant to the Section. In an updated review of available literature, OEHHA has found additional information that indicates the immune system could be a very sensitive target of malathion and this chemical could potentially impact children at very low, non-cholinergical doses (doses that do not result in overt neurotoxicity from cholinesterase inhibition). However, there is insufficient information to derive a chRD based on the immune endpoint. The U.S. Environmental Protection Agency (U.S. EPA) is requiring the registrant to develop additional immunotoxicity data as part of the re-registration process. When the immunotoxicity data become available, OEHHA will review and determine the applicability of those data to establishing a chRD. In the interim, we recommend that the chronic reference dose of 0.003 mg/kg-day for malathion developed by the U.S. EPA’s Office of Pesticide Programs be used for assessing health risk at school sites. This chronic reference dose is based on the inhibitory effects of malathion on red blood cell and blood plasma cholinesterase enzymes.
The document is considered a status report on malathion’s potential to impact children at very low non-cholinergical doses. Because this evaluation did not lead to a new quantitative assessment of malathion’s toxicity, it did not undergo external peer review or public review. Should new information be obtained that leads to a quantitative risk assessment of the chemical, that assessment will undergo the necessary and required reviews before being released.
This report is available to the public via the OEHHA Web site.
If you have any questions, please contact Carmen Milanes at (916) 323-4153, E-mail at carmen.milanes@oehha.ca.gov, or by mail at:
Office of Environmental Health Hazard Assessment
PO Box 4010, MS-12B
Sacramento, CA 95812-4010
FAX: (916) 322-9705
- Malathion