Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Additional information

Reproduction: Based on the read across data from the key three generation reproductive study using nitrilotrimethylenetris(phosphonic acid), it is unlikely that nitrilotris(methylene)]trisphosphonic acid, potassium salt will impair fertility. (Biodynamics 1979a, rel 2). 

 


Short description of key information:
The category hypothesis is that all the members are various ionised forms of the acid 6419-19-8. The main assumption is that potassium is not significant in respect of all the properties under consideration. In dilute aqueous conditions of defined pH a salt will behave no differently to the parent acid, at identical concentration of the particular speciated form present and will be fully dissociated. Hence some properties (measured or expressed in aqueous media) for a salt can be directly read-across (with suitable mass correction) to the parent acid and vice versa.

Read across data from a reliable three-generation reproductive toxicity feeding study in rats using nitrilotrimethylenetris(phosphonic acid) reported a general and reproductive toxicity NOAEL to be greater than the highest dose tested; (approximately equal to a dose of 275 mg/kg bw/day in males and 310 mg/kg bw/day for females). (Biodynamics Inc, 1979a)

Read across from a reliable teratology study in rats using nitrilotrimethylenetris(phosphonic acid) reported a maternal NOAEL to be 500 mg/kg bw/day, and the NOAEL for fetotoxicity and teratogenicity to be >1000 mg/kg bw/day. (Biodynamics Inc 1979b, rel 2).

Effects on developmental toxicity

Additional information

Developmental effects:

Based on the results from the key study which reporteda maternal NOAEL to be 500 mg/kg bw/day, and the NOAEL for fetotoxicity and teratogenicity to be >1000 mg/kg bw/day.(Biodynamics Inc 1979b, rel 2), together with the additional read across data from a pilot study to investigate theToxicity of FA 42902 in Pregnant Miceusing nitrilotrimethylenetris(phosphonic acid) (Biodynamics 1980, and Biodynamics 1979b respectively), it unlikely that in the absence of maternal toxicity nitrilotris(methylene)]trisphosphonic acid, potassium salt is a developmental toxicant.

Justification for classification or non-classification

Based upon the read across results from the key studies, nitrilotris(methylene)]trisphosphonic acid, potassium salt is not required to be classified for reproductive or developmental effects.