Neodymium di(2-ethylhexyl) phosphate

Endpoint summary

Additional information

Hydrolysis: due to the insolubility and the ready bioegradability of neodymium tris(di-2-ethylhexylphosphate), hydrolysis assay can be waived (column 2 of REACH annex VIII).

Biodegradation:

- Biodegradation in water - Screening tests: one GLP-compliant study is available. It is quoted as reliability 1 according to Klimisch criteria and flagged as a key study.

The ready biodegradability of the test item neodymium tris(di-2-ethylhexylphosphate) was evaluated using a 28-day modified Sturm test according to EEC, OECD and EPA test guidelines.

Seven flasks were used to determine the quantity of carbon dioxide evolved by the degradation of the test item: 2 inoculum blanks, 2 inoculums with the test item (10 mg TOC/L), 1 procedure control (with the reference item at 10 mg TOC/L), 1 toxicity control (reference item and the test item both at 10 mg TOC/L) and one abiotic sterile control.

The inoculum consisted of domestic, non-adapted, activated sludge (30 mg/L, dry weight/v).

The 10-day window was graphically determined to start on day 6 in the test treatment. Biodegradation of neodymium tris(di-2-ethylhexylphosphate) was 69.59% (average of two flasks) at the end of the 10-day window (on day 16) and 90.17% over the 28-day test period.

The % DOC removed from the test groups was 100%.

The level of biodegradation reached in the procedure control (82.97 % after 14 days) confirmed the integrity of the test system. Furthermore, the toxicity control revealed no adverse impact of the test item on the inoculum.

Under the experimental conditions, the test item neodymium tris(di-2-ethylhexylphosphate) was therefore readily biodegradable in the 28-day modified Sturm test.

 

- Biodegradation in water, sediment and soil - Simulation tests: based on the results of the previous experiment, neodymium tris(di-2-ethylhexylphosphate) was readily biodegradable in the 28-day modified Sturm test. As a consequence, it appears of low relevance to further assess biotic degradation. These assays were thus waived for this reason.

 

Bioaccumulation: basing the assessment on data on n-octanol/water partition coefficient, neodymium tris(di-2-ethylhexylphosphate) should not be potentially bioaccumulable according to CLP criteria. Indeed, one GLP-compliant experimental study, scored as Klimisch 1, is available and measures the partition coefficient of neodymium tris(di-2-ethylhexylphosphate) according to OECD guideline 107. The Log Kow is determined to be equal to 3.43 (thus inferior to the CLP threshold of 4). Based on this relatively low partition coefficient, the bioaccumulation assay was thus waived in accordance with column 2 of REACH Annex IX. This annex also allows waiving the test if direct and indirect exposure of the aquatic compartment is unlikely. And this is precisely the case here due to low water solubility of neodymium tris(di-2-ethylhexylphosphate).

 

Adsorption/desorption: No data are available on neodymium tris(di-2-ethylhexylphosphate). However this assay can be waived in accordance with column 2 of REACH annex VIII, as neodymium tris(di-2-ethylhexylphosphate) is readily biodegradable in a 28-day modified Sturm test. Thus it is not necessary to conduct an adsorption/desorption test.