In late April, the U.S. Environmental Protection Agency (EPA) is released a proposed interim decision (PID) to cancel all but one use of the pesticide acephate. This decision is based on EPA's updated human health draft risk assessment (HH DRA) and drinking water assessment (DWA) that were released last year, which showed significant dietary risks from drinking water for currently registered uses of acephate.
EPA also identified worker, homeowner, and ecological risks that would be mitigated by the proposed cancellations.
Acephate is an organophosphate (OP) pesticide that is registered for both agricultural uses, such as cotton and soybean, and non-agricultural uses, such as tree injections for forestry and ant mound treatment around homes. Acephate interacts with the nervous system by inhibiting the acetylcholinesterase (AChE) enzyme. This process makes the pesticide effective against insects, but it can also occur in mammals, including humans, depending on the level of acephate exposure.
At high levels of OP exposures, AChE inhibition can lead to neurological effects such as tremors, fatigue, and nausea. AChE inhibition has been found to be the most sensitive human health effect for evaluating exposures to acephate.
The Agency is proposing to maintain the use of acephate for tree injection because it does not contribute to drinking water exposure, there are no risks for workers, and, with label changes, would not pose risks to the environment. Tree injections allow the pesticide to move throughout the tree to control pests. This use of acephate is only allowed for use on trees that do not produce food for human consumption.
Acephate is proceeding through EPA's standard registration review process. The revised HH DRA and DWA released in August 2023 and the PID released in April are open for public comment for 60 days. Commenters may propose alternative mitigation for the Agency's consideration for some or all uses of acephate, and the Agency will respond to these comments in the Interim Decision.
If EPA determines that alternative mitigation options that are voluntarily agreed to by the registrant can address the identified risks to satisfy the standard for continued registration of the pesticide, this could allow EPA to put protections in place faster than the statutorily required process for involuntary cancellation that can take up to five years. Acephate is one of 18 OPs currently in registration review, with many scheduled to have interim decisions between 2024-2026.
For more information on the registration review of acephate and to provide comments on the PID and updated assessments, visit the acephate docket on regulations.gov under the docket ID EPA-HQ-OPP-2008-0915.