On August 6, 2024, EPA announced the emergency suspension of all registrations of the pesticide dimethyl tetrachloroterephthalate (DCPA or Dacthal) under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). DCPA is a pesticide registered to control weeds in both agricultural and non-agricultural settings, but is primarily used on crops such as broccoli, Brussels sprouts, cabbage, and onions.
EPA took this action because unborn babies of pregnant farmworkers and others near application sites who are exposed to DCPA, sometimes without even knowing the exposure has occurred, could experience changes to fetal thyroid hormone levels, and these changes are generally linked to low birth weight, impaired brain development, decreased IQ, and impaired motor skills later in life, some of which may be irreversible.
The suspension marks the first time in almost 40 years that EPA has taken this type of emergency action, following several years of unprecedented efforts by the Agency to require the submission of long-overdue data and then assess and address the risk this pesticide poses.
The emergency order of suspension, prohibits anyone from distributing, selling, shipping, or carrying out other similar activities for any pesticide product containing DCPA. EPA is working closely with AMVAC, the sole manufacturer of DCPA, on a return program for existing DCPA products.
On August 19, 2024, EPA received a request from AMVAC to voluntarily cancel the remaining products containing DCPA. EPA is currently working to process those requests, which includes publishing the voluntary product cancellation request for public comment.
EPA will continue to provide updates as they are available.
On this page:
- Q1: Is there risk of DCPA exposure from ingesting food and water?
- Q2: What are EPA’s plans to address DCPA tolerances?
- Q3: What activities are affected by this emergency suspension?
- Q4: Where and how much DCPA is used in the US?
- Q5: Are there any alternatives to DCPA available?
- Q6: What should growers do with existing DCPA products in their possession?
- Q7: Is DCPA used in residential applications?
- Q8: How does this emergency order differ from the 2023 suspension?
Q1: Is there risk of DCPA exposure from ingesting food and water?
A1: EPA issued its emergency suspension to protect the unborn babies of pregnant farmworkers, pregnant people who handle DCPA products, and other pregnant persons near application sites.
EPA has not identified risks from consuming foods with DCPA residues as a result of the use of DCPA on crops as allowed by registered labels. However, based on a number of conservative assumptions, EPA has identified potential risks from consuming drinking water containing DCPA residues for areas near where DCPA applications have occurred in the past. EPA models estimated drinking water concentrations based on all labeled uses for DCPA, and assumes that all applications in a watershed occur at the same time, which results in high-end estimated concentrations. With the immediate suspension and upcoming permanent cancellation of all DCPA products, there will be no additional contribution to drinking water from DCPA. EPA has posted the finalized DCPA dietary and drinking water assessments in docket ID EPA-HQ-OPP-2011-0374 at www.regulations.gov.
Q2: What are EPA’s plans to address DCPA tolerances?
A2: The emergency suspension does not change the tolerances for DCPA. However, changes to DCPA tolerances may be necessary in the future. EPA will generally initiate the process to revoke tolerances under FFDCA after all products containing that active ingredient have been canceled and the tolerances are not needed for imported food.
Please see EPA’s website for additional information on revoking tolerances.
Q3: What activities are affected by this emergency suspension?
A3: EPA has engaged with state lead agencies to ensure they are aware of EPA’s decision. The emergency suspension prohibits anyone from distributing, selling, shipping, or carrying out other similar activities for any pesticide product containing DCPA. It also means that no person can continue using existing stocks of those products. EPA and the registrant, AMVAC, have begun discussing a return program, which would include tracking of the remaining stock of DCPA products and working with stakeholders and state partners to ensure compliance with the order.
Engaging in the activities prohibited by the order constitute unlawful acts pursuant to FIFRA Section 12(a)(2)(J). EPA has authority under sections 9 and 14 of FIFRA to pursue civil and criminal enforcement actions when appropriate.
Q4: Where and how much DCPA is used in the US?
A4: The Agency completed a use, usage, and benefits assessment in spring 2023. In 2018 and 2020, US growers reported applying an average of approximately 84,000 lbs. of DCPA active ingredient annually. DCPA applications were made primarily to broccoli, cabbage, cauliflower, and dry onions, mostly in California.
DCPA was used most widely on broccoli where about 14% of the crop was treated. Otherwise, usage was uncommon (e.g., 5% of cauliflower, 3% of cabbage, and less than 2.5% of dry onion acreage treated). A 2021 survey of pesticide usage in turf, including golf courses, and ornamentals suggests little to no usage of DCPA on these use sites.
For additional information, please see the Assessment of Dimethyl Tetrachloroterephthalate (DCPA) (PC: 078701) Use, Usage, and Benefits.
Q5: Are there any alternatives to DCPA available?
A5: There are alternative herbicides for crops where DCPA is used. For onions, other herbicides include pendimethalin and bensulide. For crops like broccoli and cabbage, other herbicides such as bensulide and napropamide are available but may be less effective or could damage the crop. For broccoli, cabbage, and cauliflower grown from transplants instead of from seed, oxyfluorfen is also available. EPA included an analysis of alternatives to DCPA in its Assessment of Dimethyl Tetrachloroterephthalate (DCPA) (PC: 078701) Use, Usage, and Benefits, which is referenced in the emergency order and is available in the DCPA registration review docket. EPA also consulted with the U.S. Department of Agriculture to further understand how growers use DCPA and the alternatives to this pesticide prior to issuing the suspension.
Q6: What should growers do with existing DCPA products in their possession?
A6: Growers should contact their retailer or distributor for further guidance on return of DCPA products in their possession, and all parties may also contact AMVAC as needed for further information on the return program. The emergency order prohibits anyone from distributing, selling, shipping, or carrying out other similar activities for any pesticide product containing DCPA, other than returning product to AMVAC. It also prohibits continued use of existing stocks of those products. EPA is working closely with AMVAC, the sole manufacturer of DCPA, on a return program for existing DCPA products. AMVAC is developing a comprehensive plan designed to identify existing stocks held by distributors, retailers, and end-users, track any remaining DCPA products, and coordinate an effective and efficient collection process. EPA and AMVAC are regularly communicating on the status of the return program.
Q7: Is DCPA used in residential applications?
A7: DCPA products were used primarily in agricultural settings and commercial ornamentals (such as those in nurseries). There were no products registered for use on home lawns. There were registered uses on golf course and athletic field turf, which did have the potential to result in exposure to people working or playing on recreational turf such as golf courses. However, recent usage data suggest little to no recent usage of DCPA in turf or commercial ornamentals.
Q8: How does this emergency order differ from the 2023 suspension?
A8: In August 2023, EPA suspended the registration for the DCPA technical-grade product, which is used to manufacture DCPA products for end users, under FIFRA Section 3(c)(2)(B), due to AMVAC’s delay in providing the data EPA requested nearly a decade before. The 2023 suspension did not affect DCPA end-use products and only prohibited sale and distribution by AMVAC to manufacturers of those products. In November 2023, the suspension was lifted after AMVAC fulfilled the terms of a settlement agreement with the Agency by submitting the required data.
On August 6th, under FIFRA Section 6(c), and based on imminent hazard to the unborn babies of pregnant farmworkers, pregnant people who handle DCPA products, and other pregnant persons who live near application sites, EPA issued an emergency order for the first time in almost 40 years. This means that no person in any state may distribute, sell, ship, or carry out other similar activities for any pesticide containing DCPA. This suspension will remain in effect until completion of cancellation proceedings or unless lifted following an administrative hearing or challenge in federal court.
