U.S. EPA proposes improved mitigation for insecticide carbaryl, including pilot for protecting endangered species

On December 1, 2022, the U.S. Environmental Protection Agency (EPA) proposed measures to improve protections for human health and the environment, including endangered species, from exposures to carbaryl, an insecticide that is used on a wide variety of food and feed crops, as well as in turf management, ornamental production, rangeland and residential settings.

Carbaryl is currently undergoing Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) pesticide registration review. This process requires EPA to reevaluate each pesticide every 15 years to ensure that risk assessments and risk management decisions reflect the best available science. The improved protections are included in EPA’s proposed interim decision (PID), which is a key step in registration review. The PID includes proposed mitigations to address potential risks of concern outlined in EPA’s human health and ecological draft risk assessments.

The PID also provides a pilot for evaluating and proposing early mitigation for four vulnerable endangered species while formal endangered species consultation with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service (the Services) is ongoing. This effort is part of EPA’s strategies identified in its comprehensive Endangered Species Act (ESA) Workplan released in April 2022 and the November 2022 update that aim to pilot improved protections for listed species from select conventional pesticides to help meet the Agency’s ESA obligations.   

Finally, EPA is also proposing additional ESA mitigation measures to implement the outstanding 2009 Salmonid Species Biological Opinion from the National Marine Fisheries Service, which will also provide protections for these species.

Proposed Mitigations to Protect Human Health

In 2021, EPA released the revised draft human health risk assessment (DRA) for carbaryl, which identified potential risks of concern such as neurotoxicity in the central and/or peripheral nervous system for some carbaryl uses and products approved for use in residential settings; to bystanders from spray drift exposure when certain carbaryl applications are made; to people who mix, load and apply carbaryl; and to people who work with certain carbaryl-treated crops.

To address the potential risks of concern for workers mixing, loading, and applying carbaryl identified in the human health DRA, EPA is proposing application rate reductions for sweet corn, turf, and citrus use sites.

In addition, EPA is proposing:

• Some use cancellations for residential dust formulations, residential granular formulations on turf, use on rice, and backpack applications to control tree boring beetles;

• Additional personal protective equipment (PPE) for some uses; and

• Longer restricted entry intervals for some uses.

For the U.S. Forest Service’s use of carbaryl in boring beetle control, EPA is proposing: 

• Chemical-resistant hats and aprons as additional PPE requirements;
  

• A reduction in the amount of solution that may be handled by a single worker per day; and

• Cancellation of the backpack method of application to mitigate potential risks to individuals mixing, loading, and applying carbaryl.

Proposed Mitigations to Protect Environmental Concerns to Non-Target Species

EPA released the carbaryl ecological DRA in 2021. The ecological DRA identified potential risks of concern to mammals, birds, honeybees, fish, and aquatic invertebrates on an acute and chronic basis, as well as potential risks of concern to aquatic plants.

To address these potential risks of concern, EPA is proposing:

• Mandatory spray drift language that prohibits application within 25 feet of aquatic habitats for ground applications and 150 feet for aerial applications;

• Mitigation to reduce runoff through protection statements and application restrictions during rain; and

• Measures to protect pollinators from carbaryl exposure, including restrictions on applications during bloom.

Proposed Mitigations to Protect Certain Listed Species

Carbaryl is a pesticide selected for one of several early mitigation pilots discussed in the April 2022 ESA Workplan that will identify early ESA mitigation measures for a subset of species before the start of formal consultation.

In March 2021, EPA released the final biological evaluation (BE) for carbaryl. The BE contains EPA’s effects determinations and analysis of the potential effects of carbaryl to listed species and their designated critical habitats.

Because EPA made a number of ″likely to adversely affect″ (LAA) determinations, EPA initiated consultation with the Services when it completed the final BE. These determinations mean that EPA reasonably expects that at least one individual animal or plant, among a variety of listed species, may be exposed to the pesticide at a sufficient level to have an adverse effect. The likely ″take,″ which includes unintentional harm or death, of even one individual of a species, is enough to trigger such a determination. This is the case even if a species is almost recovered to a point where it may no longer need to be listed. As a result, there are often a high number of LAA determinations in a BE. An LAA determination, however, does not necessarily mean that a pesticide is putting a species in jeopardy.

Considering a range of taxa and life histories and incorporating recommendations from carbaryl registrants, EPA selected four ″pilot″ species that it identified as LAA in the BE to evaluate further: squirrel chimney cave shrimp, Miami tiger beetle, Upper Columbia River steelhead trout, and wireweed.

For the Upper Columbia River Steelhead trout and wireweed, for which EPA predicted jeopardy/adverse modifications, the Agency is proposing additional mitigation to minimize carbaryl exposure. EPA is not proposing additional ecological mitigation measures at this time, beyond the non-target species mitigation mentioned above, for the squirrel chimney cave shrimp or the Miami tiger beetle because the Agency does not predict jeopardy/adverse modification for these species.

EPA’s draft likelihood of jeopardy and adverse modification predictions examine effects of carbaryl at the species scale (i.e., at the population level rather than an individual of a species). To learn more about these listed species and how EPA’s proposed mitigation measures are expected to be protective, read page 61 of EPA’s PID.

Proposed Mitigations to Protect Listed Salmon Species

EPA is also proposing mitigation to protect listed salmon species in the Pacific Northwest. In 2009, the National Marine Fisheries Service released a biological opinion that addressed effects of carbaryl on Pacific salmonids. In this PID for carbaryl, EPA is proposing modifications to the reasonable and prudent alternatives (RPAs) outlined in the 2009 biological opinion. RPAs are mitigation measures that the Service has identified to avoid jeopardy or adverse modification.

Under the EPA proposed modifications to the RPAs outlined in the biological opinion, users may select from a number of drift and runoff-reduction techniques intended to protect listed salmonid and steelhead species in Washington, Oregon, Idaho and California, including vegetated filter strips, retention ponds, water control structures, no-till/reduced tillage practices, riparian hedgerow, and no-spray buffers.'

To focus the mitigations where they are most needed while retaining options for carbaryl users, the proposed mitigation measures for the listed species would be targeted in specific geographic areas most relevant to the species. The PIDs include proposed mitigation measures to be included on the Bulletins Live! Two website for the salmon species.

Next Steps

The PID represents the next step in the registration review process for carbaryl. The public can comment on the PID for 75 days in the carbaryl registration review docket at EPA-HQ-OPP-2010-0230 at www.regulations.gov. After the PID, the next step in the registration review process is issuing an interim decision.