N,N'-diacetylhydrazine

Toxicity to other aquatic organisms

Description of key information

Acute amphibian toxicity: LC50=18.96g/L, 96h, embryos of the African clawed frog, FETAX (ASTM E1439-98), Schultz 1998
Sublethal effects: EC50=12.72g/L, 96h, tadpoles of the African clawed frog, FETAX (ASTM E1439-98), Schultz 1998

Additional information

Schultz et al (1988) investigated the test item, for lethal and morphological effects (teratogenicity, malformations) to embryos of the African clawed frog (Xenopus laevis). The non-GLP study was conducted according to the Frog Embryo Teratogenesis Assay-Xenopus (FETAX) protocol according to ASTM E1439-98. The experiments are considered “reliable with restrictions” (Klimisch 2), conclusive with regard to the establishment of acute lethal and sublethal effects and thus adequate for risk assessment and classification and labelling.

The test organisms in the stage of early to mid-blastula embryos were exposed via the aqueous medium during 96 hours to a series of not further specified graduated concentrations of the test chemicals or pure medium (control). The effects were compared to the reference substance (positive control) Semicarbazide hydrochloride (CAS 563-41-7), from which teratogenic effects were well known as evidenced by the authors, and which represents the common structural element of the substances investigated by Schultz et al (1988). The specific effect of the reference is Osteolathyrism, a collagen cross-linking deficiency. Accordingly histological and electron microscopical examinations were conducted on representative embryos with emphasis on the axial skeleton. Additionally developmental stage, length, macroscopic malformations and mortality were recorded.

The test item was able to induce osteolathyrism (Mekenyan et al 1996) and gave thus a positive teratogenic response with a 96 h EC50 of 12.72 g/L, which is 109.51 mmol/L. This EC50 indicates a 2190 times less effectiveness than the positive control on molar basis. The 96 h LC50 of the test item was determined to be 18.96 g/L or 163.30 mmol/L, which is less toxic than the reference substance by a factor of 2.86 on molar basis.

In conclusion the test item did not exhibit acute toxicity to aquatic amphibians up to the cut-off limit of 100 mg/L and no classification or labelling requirement is implicated by the results of this study. As the 50 % teratogenic response was observed at concentrations in the order of magnitude of lethality and a 2190 times higher molarity than the reference, osteolathyrism is not considered a relevant effect of the test item at environmental concentrations.