Impaired physiological responses and neurotoxicity induced by a chlorpyrifos-based formulation in Caenorhabditis elegans are not solely dependent on the active ingredient.

The current massive and indiscriminate agrochemicals usage, which is inexorably linked to the toxic consequences to the environment and people, represents a great concern. Our work aimed to compare the toxicity induced by chlorpyrifos in its pure form (CPF) with that of a commercial formulation containing allegedly inert ingredients (CBCF) using Caenorhabditis elegans as in vivo model. After a 48 h exposure period, CBCF was 14 times more lethal than CPF; Hatching, brood size, body length and motor-related behavioral parameters were decreased, but these effects were significantly higher in CBCF-exposed worms. Additionally, CBCF induced significant morphological changes in cholinergic neurons, which are associated with the motor-related behavioral parameters. Finally, by analyzing the CBCF, we detected the presence of potentially-toxic metals that were not specified in the label. The presented results highlight the toxicological relevance of components present in the commercial formulations of pesticides, which have been claimed as inert compounds.