1,3-Dichloropropene Health Risk Mitigation and Voc Emission Reduction Regulations: Questions and Answers

Effective January 1, 2024, the Department of Pesticide Regulation (DPR) adopted or amended regulations to restrict use of 1,3-dichloropropene (1,3-D) when used to fumigate soil to grow an agricultural commodity (Title 3, California Code of Regulations [3 CCR] sections 6448 through 6448.4, 6449.1, 6452, 6452.2, 6624, 6626, and 6881).

Between November 2023 and January 2024, staff from DPR’s Environmental Monitoring (EM) Branch held trainings for County Agricultural Commissioner (CAC) staff on these changes. The presentation slides and other related information are available on our website at 1,3-Dichloropropene Field Fumigation and Regulation Training This letter responds to questions EM received at those trainings.

General

Q1. Who tracks the township cap?

A: As they have for the last several years, Telus (formerly Agrian) tracks the 1,3-D township cap for the registrant, Salt Lake Holdings LLC, a wholly owned subsidiary of The Dow Chemical Company.

Q2. Must CAC staff also track 1,3-D use?

A: No, Telus is responsible for tracking 1,3-D use, including calculating the adjusted pounds for each 1,3-D application and tracking the adjusted total pounds (ATP) for each township to ensure the annual township cap of 136,000 ATP is not exceeded. CACs continue to have discretion on tracking the township cap internally if they wish.

Q3. For Telone II, there appears to be an inconsistency in how Telus calculates the broadcast-equivalent application rate and the pounds of 1,3-D for township cap purposes compared to what you get if you use the information on the label. What is the correct amount of 1,3-D per gallon?

A: For Telone II, both DPR and Telus use 9.848 lbs 1,3-D/gal to calculate the amount of 1,3-D for the township cap and application rates. This value is consistent with the 9.85 lbs 1,3-D/gal specified by the label, after rounding. The inconsistency is due to an error in the product density listed on the label. DPR discussed this issue with the registrant and Telus (formerly Agrian) several years ago and all parties agreed that the 10.15 lbs/gal density specified by the labeling was incorrect. The correct product density is 10.1 lbs/gal, as specified by the registration data provided by the registrant. CAC staff can double check the product density value using DPR’s Product/Label Database application at California Product/Label Database Application.

Notices of Intent (NOIs) and Pesticide Use Reports

Q4. What is a ‘Dow contractor-approved’ recommendation? Does DPR have a list of approved contractors?

A: Telus is currently the only Dow contractor approved to track use of 1,3-D. The Pest Control Adviser (PCA) recommendation and NOI must be submitted using the Telus system.

Q5. What should CAC staff look for when reviewing 1,3-D NOIs?

A: As is the case with all NOIs, CAC staff should continue to verify the accuracy of the information submitted on the NOI. For 1,3-D NOIs specifically, checking the application factor (AF) will ensure that Telus is correctly calculating ATP. Confirming the accuracy of NOIs will help ensure that the use of 1,3-D does not exceed the township cap. DPR recommends that CACs review the following specific items on the NOI for accuracy:

• Correct AF.
• Allowed field fumigation method (FFM) for tree/grape applications.
• Allowed FFM for applications in ozone nonattainment areas (NAAs) during May-October.
• Verify setback requirements (distance and acreage) for selected application scenario.
• Vacating agreements submitted (if required).
• Check if overlapping application requirements apply.

Q6. Who is the Dow contractor for pesticide use report submittal?

A. As noted in Compendium Volume 3 Appendix J under 1,3-D use reporting, 3 CCR section 6626(g)(1) requires 1,3-D use reports to be submitted electronically in a manner specified by the commissioner. Commissioners should require use reports to be submitted electronically using Telus.

Q7. Do pest control businesses (PCBs) have to pay to have an account through Telus that allows use report submittal?

A: Yes, the registrant only allows PCBs to purchase 1,3-D if they have and use Telus to generate the PCA recommendation, NOI, and submit the PUR. This is necessary for Telus to accurately track ATP for each township. PCBs must pay for a Telus account. Dow does not require growers to have a Telus account. They can obtain copies of the PCA recommendation and PUR from Telus at no charge.

Compendium Volume 3, Appendix J

Q8. In Section J.2, there is an inconsistency in the minimum time to cut/perforate a totally impermeable film (TIF) tarp. Page J-5 specifies nine days but the regulations specify ten days. Which is correct?

A: The regulations are correct. 3 CCR section 6448.2(a)(4) states that, “TIF tarpaulins must not be cut/perforated until a minimum of 10 days (240 hours) have elapsed after the application is complete.” DPR will revise Appendix J to delete the nine-day requirement.

Q9. In Section J.3, DPR provides an example of how overlapping setbacks work. What happens if two neighboring fields, each 80 acres and using TIF tarp, want to fumigate at the same time?

A: For purposes of illustration, we will consider two 80-acre applications using FFM 1242 (TIF tarpaulin/shallow/broadcast). Tables 6a-6d in the 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024, Document have the same 80-acre limit and 100 ft setback regardless of rate, location, or month of application.

To not be considered “overlapping,” the distance between the two blocks must be greater than or equal to the combined setbacks. If the minimum separation requirement (100 ft setback + 100 ft setback = 200 ft separation) is not met, the two applications on the same day would be considered a single application block with an 80-acre limit. The CAC must deny at least one of the NOIs, as the combination would violate 3 CCR section 6448(e).

Adjacent applications using TIF tarp can occur on consecutive days (i.e., a 36-hr separation is not required).

Q10. In Section J.4, Table 1, FFM 1206 is listed as Nontarpaulin/Deep/Broadcast or Bed. However, the text of 3 CCR section 6448.2(d)(5) does not include “Bed” for this method. What is correct?

A: The regulations are correct. 3 CCR section 6448.2(d)(5) lists “Nontarpaulin/Deep/Broadcast” and does not include “Bed” for this method. FFM 1206 is not allowed for bed fumigations. DPR will revise Appendix J to delete “or Bed” from FFM 1206 in Tables 1 and 2.

The 1,3-Dichloropropene Field Fumigation Requirements, Est. January 1, 2024, Document, Incorporated by Reference

Q11. The Document appears to contain a typo on page 4 (the reference to page 17 likely should be page 32).

A: The page reference is a typo and should be page 32. DPR will amend the Document by rulemaking to correct the typo.

Q12. In the setback tables, why is the acreage limit the same for some application rates and setback distances? For example, in Table 2a at 150 pounds per acre both the 300’ and 400’ setbacks appear to have a 10-acre limit. What setback distance is required?

A: The same acreage being listed on two setback distances for a specific application rate is a common issue found on many of the tables in Section 3 of the Document. The shorter setback distance for a given rate-acreage combination is sufficiently health-protective and supported by DPR’s analysis. The duplicate acreage limits in the tables are similar to the dashes (—) that may appear in the setback distance tables. When used, those dashes indicate the shorter setback distance is sufficient and health protective. In the Table 2a example given, at the 150 lbs/acre application rate a 5-10 acre application block requires a 300ft setback and a 10-15 acre application block between requires a 500ft setback.

Q13. Using Table 2d, for an application at 90 lbs/acre and setback distance of 500’ from an occupied structure the field size is listed as 10 acres. For the field in question, the closest occupied structure is over 700’ from the perimeter of the application block. Can they fumigate all 13.3 acres at once since the closest occupied structure is over 500’ away, or does the table mean the maximum number of acres that can be fumigated is 10 acres?

A: The application block size at 500’ is the maximum application size allowed for the associated method and application rate. For this example, the application block would have to be divided into two applications 36 hours apart, or they could switch to using another method with smaller setbacks, such as using a TIF tarp.

Other Regulation Requirements

Q14. Can residents reenter a structure for a limited time during the 7-day setback duration? Can they go and pick up something they forgot? Can they go and feed pets/animals? If yes, what is the limit for the number of hours for occupancy?

A: As stated in the Initial Statement of Reasons, the setback distance and related requirements address the potential 72-hour acute risk and 70-year lifetime cancer risk to nonoccupational bystanders. Thus, 3 CCR section 6448(b) requires that no person shall be present at the structure at any time during the application and for at least the seven consecutive day period after the application is complete.

The regulation does not make allowances for individuals to return to the structure during the setback duration period. Even short visits could result in health risks, especially during the first 72 hours after application. The CAC should carefully evaluate the site-specific nature of any request to enter a structure during the setback period, including the distance between the structure and the field, weather conditions, and the time since the application was completed.

Q15. Are CACs required to go back and check if the structure is vacated or can they rely on the written agreement?

A: 3 CCR section 6448(b)(1) requires a copy of the written vacating agreement be provided to the CAC with the NOI. DPR leaves the decision to check the structure to the discretion of the CAC. CACs should follow the same procedures they would normally do with other soil fumigants where the occupant agrees to voluntarily vacate a structure or facility. For example, if CAC staff do a use monitoring inspection during application, or visit the site for another reason during the seven-day setback period, and they see unanticipated activity at the structure, they may want to follow-up and investigate if the written agreement has been violated.

Q16. If the product contains chloropicrin and 1,3-D, are the application methods for tree and grape crops restricted to only FFM 1225, 1250 and 1264 May – October in the NAAs?

A: Yes. Despite being low VOC for 1,3-D, methods 1224, 1226, and 1227 are considered high-VOC for chloropicrin. These methods are prohibited in the San Joaquin Valley, Southeast Desert, and Ventura ozone NAAs during May – October.

Q17. For nursery crops that consist of deciduous tree or grape nurseries, does the application have to be a 24” deep method? The 24” depth conflicts with CDFA’s Nursery Inspection Procedures Manual.

A: No. 1,3-D applications on soils used to produce tree and grape nursery stock are not required to use a 24” or TIF fumigation method.

Q18. Why are tree hole fumigations with 1,3-D not allowed?

A: Tree hole fumigations use a hand probe to inject the fumigant at the spot where a tree will be planted. This method is currently not one of the approved methods specified in Section 6448.2(d).

However, since the regulation went into effect, DPR has received information about a tractor-mounted system to fumigate tree holes that was unknown to DPR. DPR is evaluating the information provided and will consider granting interim approval for this method following the requirements in 3 CCR section 6448.3.

If you have any additional questions about this regulation, please direct them to the Enforcement Headquarters Branch.

Sincerely,