On the terrestrial toxicity of the fungicide imazalil (enilconazole) to the earthworm species Eisenia foetida.

The toxicity of imazalil (enilconazole), of its sulfate salt, and of a principal environmental transformation product to the earthworm species Eisenia foetida was determined. The 48-hr contact test and the 14-day artificial soil test as described by OECD guideline 207 were carried out. Concentrations of the parent substance in earthworm tissues at the end of the exposure in soil were determined by gas chromatography. The LC50 of imazalil was 12.8 micrograms/cm2 in the contact test and 541 micrograms/g in the artificial soil test. The LC50 values of the sulfate salt were 11.6 micrograms/cm2 and 532 micrograms/g, respectively. The transformation product had a LC50 of 108 micrograms/cm2 in the contact test, and the survival in the soil test exceeded 90%, even at levels of 1000 micrograms/g. Tissue levels of imazalil in surviving worms were always lower than the concentrations in corresponding soil. The LC50 values largely exceeded the levels expected after normal use. Therefore, the fungicide is not considered to be harmful to earthworms in the soil environment.