Tag Archive for: Herbicide

EPA Issues Notice of Intent to Suspend the Herbicide DCPA

This announcement was published by the EPA on April 29, 2022. Click here for more information.

Today, the U.S. Environmental Protection Agency (EPA) is issuing a notice of intent to suspend (NOITS), which when effective, will prevent the sale, distribution, and use of the technical-grade product containing the pesticide dimethyl tetrachloroterephthalate (DCPA). Technical-grade products are high-concentration forms of pesticides that are formulated into other end-use pesticide products. EPA is issuing this NOITS for DCPA because AMVAC, the sole registrant, has not provided the full complement of data the Agency required it to submit over nine years ago. Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the registrant is required to submit data to support the continued registration of this product. Due to the registrant’s long-standing failure to respond to EPA’s requests for necessary data, the Agency is unable to fully evaluate the risks associated with DCPA.

DCPA is an herbicide applied to control grasses and certain broadleaf weeds in both agricultural and non-agricultural settings. Agricultural use sites include cole crops (e.g., broccoli, kale, cabbage), cucurbits, tomatoes, onions, and herbs. Non-agricultural use sites include non-residential turf and ornamentals.

As required by FIFRA, EPA periodically re-evaluates pesticides through registration review to ensure that risk assessments and pesticide decisions reflect the best available science. Part of the registration review process is to identify risks of concern and to implement actions that can mitigate these risks. To ensure access to the needed data, the Agency notifies registrants of the data requirements through issuance of a FIFRA Data Call-In Notice (DCI).

In 2013, EPA issued a DCI to AMVAC requiring it to submit more than 20 studies to support the existing registrations of DCPA. In the nine years since the requirements were imposed, the Agency has reviewed numerous insufficient studies provided by AMVAC, and also has evaluated more than 20 waiver requests seeking to remove these data requirements. In its attempts to obtain the needed data, EPA has spent its finite resources on these efforts to review the many submissions, some of which otherwise would have been used to focus on pesticide actions requested by other registrants and needed by growers.

The data required by EPA included a comprehensive study of the effects of DCPA on thyroid development and function in adults and before birth. In the absence of these data, EPA reviewed preliminary data submitted by AMVAC, which suggest that DCPA can affect thyroid function at lower doses than previously known, and that it may affect a fetus at lower doses than those that adversely affect adults. Without complete data on the thyroid toxicity of DCPA, the Agency is unable to complete the scientifically robust and defensible human health risk assessment needed to evaluate whether DCPA products continue to meet the standard for registration under FIFRA.

After 30 days, the NOITS will become final (subject to the conditions discussed below) and it will be illegal for the registrant to distribute, use, or sell its technical-grade DCPA pesticide product until EPA lifts the suspension. This means that once the technical-grade product is suspended, it will be illegal for AMVAC to use it to formulate the end-use products used by growers. Stocks of DCPA end-use pesticide products that have already been formulated prior to the suspension may continue to be distributed, sold, and used according to the label. If the suspension continues and the existing stocks are depleted, users may not have access to end-use product. However, under FIFRA the suspension will not become final if within 30 days from issuance of the NOITS, one of the following two things happens:

  • AMVAC submits all the required data, and EPA determines that it has fully complied with the DCI requirements that served as a basis for the NOITS; or
  • Consistent with FIFRA requirements, AMVAC or a person adversely affected by the Notice makes a timely and adequate request for a hearing. A hearing must be held and a determination on the suspension issued within 75 days after receipt of a hearing request, unless all parties stipulate to such an extension.

If the registrant submits the missing data after the suspension becomes effective, EPA can lift the suspension. Upon publication of the NOITS in the Federal Register, all supporting documents will be available in the DCPA registration review docket EPA-HQ-OPP-2011-0374 at www.regulations.gov.

EPA Proposes Registration of Trifludimoxazin, a New Herbicide Active Ingredient

This original announcement was published by the EPA on December 12, 2020. Click here for more information.

 

The U.S. Environmental Protection Agency (EPA) is proposing to register pesticide products containing the new active ingredient trifludimoxazin, a vital additional tool in managing resistant weeds.

Trifludimoxazin is an herbicide intended for pre- and/or post-emergent control of broadleaf and grass weeds. It can be applied by aircraft on citrus fruits, pome fruits, cereal grain (except rice), tree nuts, peanuts, and foliage of legume vegetables. Non-agricultural use sites include tree plantations, industrial landscaping, native grass openings, and conifer and hardwood plantations.

EPA reviewed trifludimoxazin and determined there are no human health risk concerns.

EPA is proposing specific mitigations to address potential ecological risks, including label instructions to reduce spray drift by using a medium to ultra-coarse spray nozzle, and resistance management strategies to reduce the potential for herbicide resistance. The label also includes advisory language to prevent off-site movement to non-target areas due to runoff, along with application restrictions and recommendations on what types of soils and substrates to avoid.

EPA is accepting public comments on this proposal via docket EPA-HQ-OPP-2018-0762 at www.regulations.gov for 30 days.

EPA Proposes Registration of New Herbicide to Aid in Resistance Management

This original announcement was published by the EPA on August 1, 2020. Click here for more! 

 

EPA is proposing to register a new active ingredient, tiafenacil, a contact herbicide.

EPA proposes tiafenacil for pre-plant and pre-emergence burndown use in corn (all types except sweet corn), cotton, soybeans and wheat. Proposed post-emergence uses include directed burndown in grapes, burndown in fallow and non-crop areas, and as a crop desiccant in cotton. There are no residential uses for tiafenacil proposed in this decision.

Tiafenacil is expected to be useful for herbicide-resistance management. It provides an alternative for controlling glyphosate-resistant Palmer amaranth in cotton, suppressing glyphosate-resistant marestail in corn and soybeans, and controlling waterhemp in corn and soybean.

The need for additional tools such as tiafenacil to manage these resistant weeds is growing, as herbicide resistance presents a significant financial, production and pest management issue for growers throughout the nation.

EPA assessed tiafenacil for registration on soybean, corn and cotton as a workshare with Canada’s Pesticide Management Regulatory Agency (PMRA), with both agencies conducting separate assessments and then sharing results.

The database for tiafenacil indicates the chemical is generally low risk to non-target organisms other than plants, so most mitigation measures deal with avoiding contact with non-target plants. No other substantial risk mitigation was deemed necessary for the proposed uses.

EPA has not identified any dietary, residential, aggregate or occupational risks of concern for human health; therefore, no mitigation is being proposed.

Tiafenacil is proposed to be registered as one technical product and two end-use products.

The public comment period for this proposed decision will be open for 30 days, closing on Aug. 30, 2020. Visit Docket No. EPA-HQ-OPP-2019-0413 to read more and submit comments.