Neodymium di(2-ethylhexyl) phosphate

Endpoint summary

Additional information

The ability of neodymium tris (di-2-ethylhexylphosphate) to induce genetic damage was assessed in an in-vivo micronucleus assay performed according to internationally recognised guidelines and in compliance with GLP. This study was scored as validity 1 according to Klimisch criteria and thus considered as the key study.

No in-vitro assays are available, as it was technically impossible to perform the tests. Indeed, neodymium tris(di-2-ethylhexylphosphate) is not soluble in the vehicles usually used in in-vitro tests (water, dimethylsulfoxide, acetone, ethanol, tetrahydrofurane). During preliminary assays, no homogeneous suspension (to the naked eye) could be obtained in these vehicles at concentrations as low as 1 or 10 mg/mL to allow treatment in adequat conditions.

 

In a bone marrow micronucleus study performed according to OECD 474, EU B.12, EPA OPPTS 870.5395 and GLP (CIT report No. 33215 MAS, 2008), scored as validity 1 according to Klimisch criteria, three groups of five male and five female mice were given neodymium tris (di-2-ethylhexylphosphate) in corn oil at dose-levels of 500, 1000 and 2000 mg/kg/day by oral route, over a 2-day period (two treatments separated by 24 hours). Concurrent vehicle control (corn oil) and positive control (cyclophosphamide) were tested in parallel.

The animals were killed 24 hours after the last treatment.

For each animal, the number of the micronucleated polychromatic erythrocytes (MPE) was counted in 2000 polychromatic erythrocytes. The polychromatic (PE) and normochromatic (NE) erythrocyte ratio was established by scoring a total of 1000 erythrocytes (PE + NE).

 

Neither mortality, nor clinical signs were observed in the animals of either sex at any dose-levels.

The mean values of MPE as well as the PE/NE ratio in the groups treated with the test item, were equivalent to those of the vehicle group. The vehicle and positive controls gave appropriate response, consistent with the historical data.

 

Under these experimental conditions, neodymium tris (di-2-ethylhexylphosphate) did not induce damage to the chromosomes or the mitotic apparatus of mice bone marrow cells after two oral administrations, at a 24-hour interval, at the dose-levels of 500, 1000 and 2000 mg/kg/day.

From the result described above, it can be concluded that neodymium tris (di-2-ethylhexylphosphate) did not induce any chromosome aberration in-vivo and therefore should not be classified for genetic toxicity.

Short description of key information:
No indication of genetic toxicity was observed in an in vivo micronucleus assay performed with neodymium tris(di-2-ethylhexylphosphate).

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the classification criteria of Annex VI Directive 67/548/CEE or UN/EU GHS, and considering the negative result obtained in the in-vivo micronucleus test using neodymium tris (di-2-ethylhexylphosphate), no classification for mutagenicity is required.