The great expansion that in recent years has been in the use of plant biostimulants has underestimated the possibility of producing environmental risks. The objective of this study was to evaluate the cytotoxicity, genotoxicity and toxicity of three different biostimulants (widely marketed in Brazil and exported to other countries) – A, B and C - on both plant and animal indicator organisms. In A. cepa, the concentrations evaluated for the products A and B (0.0625 at 0.500 mL/L), and C (0.0625 at 0.500 g/L) induced inhibition of cell proliferation on meristems, in at least one considered time of analysis, characterizing them as cytotoxic. A, B and C did not induce cellular changes and were not genotoxic. In the test with A. salina, different concentrations of the biostimulants were tested, ranging from 1000 - 1.95 ppm and the toxic potential was evaluated through the LC50. The three products showed high toxicity (LC50 <100 ppm) against microcrustaceans.

Keywords: Cell changes, Cell changes, Mitotic index, Mortality, Plant regulator.