Environmental release of a safener fenclorim from rice (<i>Oryza sativa</i> L.) following seed treatment

Abstract The safener fenclorim, effective in protecting rice ( Oryza sativa L.) from the phytotoxicity of some herbicides, is regarded as a contaminant of emerging concern that may cause toxicological issues to ecosystems and humans who may consume the final harvested rice. This study investigated time‐dependent environmental releases of fenclorim from rice seeds treated with the safener and insecticide with five different treatments. The treatment with fenclorim alone caused the greatest fenclorim releases from the seed, and the release magnitude was similar to the treatment that had fenclorim and insecticide in mixture. The fenclorim release was the least when treated with safener and insecticide in sequence. Based on the previous literatures, all fenclorim release magnitudes observed in this study were at toxicologically safe levels for various living organisms in the soil, and fenclorim residues determined in the final rice harvest were also safe levels below the instrumentally detectable level. Core Ideas Seed treatment with safener alone causes the largest fenclorim release to environments. Seed treatment with safener and insecticide in sequence minimizes fenclorim releases. Fenclorim residues in the final rice harvest were below the detectable level. The fenclorim used will not cause residual issues in the ecosystem and harvested rice.