Discussion

• Pesticide residues were detected in all 21 products tested.
• No product was found to exceed the maximum residue limits (MRLs). All products were assessed as compliant under the Food Sanitation Act.
• The results confirm that U.S.-origin organic raisins distributed in Japan show the same trends as those reported in the USDA survey. For consumers who choose organic raisins expecting minimal pesticide exposure, the detection of residues in these products may be cause for concern.
• The insecticides bifenthrin and methoxyfenozide — both detected at high rates in the USDA survey — were found in every sample tested, whether from the 2023 or 2025 survey periods.
• The neonicotinoid insecticide imidacloprid was detected in 5 products.
• Returning to the principles of organic certification, the question arises: why are pesticides — which should not have been used — being detected? Possible routes of contamination in organic produce include:
  　1. Accidental use or errors during cultivation
  　2. Drift — pesticides applied to neighboring conventional farmland carried by wind
  　3. Pesticide adhesion via dust during raisin drying that could not be fully removed by washing
  　4. Contamination through shared processing lines used for both organic and conventional raisins
  　5. Products that are not genuinely organically grown
  　6. Use during processing through currently unknown methods
  　7. Adhesion of pesticides used during warehouse fumigation
  　8. Post-harvest treatment (protection against flies attracted during drying)
  among other possibilities.
• Considering that tap water or groundwater may be used during processing, we searched for research on pesticide contamination in groundwater and tap water in California and similar regions, but could not find data showing detection of bifenthrin or methoxyfenozide, and the connection remains unclear.
• Why bifenthrin and methoxyfenozide are consistently detected across organic raisins from what are presumably different production sites, growers, and manufacturers requires further investigation and information gathering. There may be processing practices used in U.S. raisin production that are not publicly known, and these pesticides may be applied at some stage in that process.
• We contacted both USDA and raisin producers by email to ask how they analyze the cause. The USDA pesticide survey team indicated that they do not carry out cause analysis. As of this writing, no response has been received from SUN-MAID (SUN-MAID), one of the world's largest raisin producer cooperatives based in California.
• Among the products tested, some showed detections exceeding 0.1 ppm. Even accounting for concentration due to drying during processing, these levels seem high for raisins produced under an organic label. For these products, there is a possibility that inappropriate practices occurred somewhere in production or distribution.
• This survey was not conducted to investigate the liability of those involved in the distribution of U.S.-origin organic raisins. Given that the reason for widespread pesticide detection in U.S.-origin organic raisins is not yet understood, we believe the most desirable outcome is for the causes to be identified and improvements made — so that products can be produced that meet the expectations of both farmers and consumers who hope organic produce will be free from pesticide residues. We have heard that many manufacturers selling certified organic agricultural products work hard to plan and produce products that meet consumer requests. We hope that cooperation and solidarity among producers, manufacturers, and consumers will lead to solutions to this challenge.
• This survey focused on U.S.-origin organic raisins, but for reference, one Turkish product (S18 in Table 2) was also tested. It showed detection of the neonicotinoid acetamiprid and the organophosphate insecticide chlorpyrifos-methyl. Bifenthrin and methoxyfenozide, which were prominent in U.S.-origin raisins, were not detected. With only one sample it is difficult to draw conclusions, but this result may suggest a different detection pattern from U.S.-origin raisins. If the reason for this difference could be traced, it might point toward processing conditions or environmental factors at U.S. raisin production sites that are linked to the detection of bifenthrin and methoxyfenozide. Going forward, we plan to conduct comparative surveys with organic raisins from other countries such as Turkey and Chile, and with non-organic raisins. We appreciate your support for future survey funding (Online Donation).
  
  Table 2 [Reference Sample] Pesticide Residue Analysis Results for Turkish Organic Raisins
  

  No.	Photo	Product Name	Seller / Manufacturer / Processor, etc.	Analysis Results (ppm)
  S18		Origin: Turkey Organic Thompson Raisins Best before: 2025.06.21 LOT20240909	Tokura Shoji Co., Ltd.	Acetamiprid Chlorpyrifos-methyl	Trace (0.002) Trace (0.001)

  
  

Reference Data — From the USDA (PDP) Pesticide Survey Database

Related Links

About the Nouminren Food Research Laboratory

　The Nouminren Food Research Laboratory is a rare analytical facility established in 1996 through donations from many farmers and consumers. Because it was founded by public donation, it operates independently without influence from corporations or government bodies.

　Since our founding in 1996, our research activities have been sustained entirely by donations. Frankly, our financial situation is challenging. Your support is essential for us to continue operating from the perspective of farmers and consumers.

　We are currently recruiting supporting members ("Analysis Center Supporter Members"). Membership starts at an annual fee of 5,000 yen or more per unit. Please help support our work.

"Analysis Support Donation" and "Supporter Member Registration" (via the crowdfunding service Congrant)