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Administrative data

Description of key information

LD50 (oral): 300 - 2000 mg/kg bw
LD50 (dermal): 508 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
discriminating dose
Value:
300 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion
Dose descriptor:
LD50
Value:
508 mg/kg bw

Additional information

The test substance was subject to an oral LD50 test and an acute dermal LD50 test on rabbits in studies conducted comparably to current standards/guidelines. Due to its instability, the submission substance cannot be obtained in pure form. Dermal toxicity testing was performed with material containing 45 % of the submission substance and in a conservative way all toxicity was assigned to the submission substance. Therefore, the actual dermal LD50 value might be higher than that obtained from studies with the mixture.

As the concentration of NiL4 in the test material of the acute oral toxicity study was only 10% this information is not used for hazard assessment. Key information is derived from a valid oral toxicity study with the ligand TTP.

Oral:

A mixture with 10% test substance was tested for acute oral toxicity in rats. It was administered by gavage at different doses. Animals showed a range of clinical signs and lethality. All deaths occurred within 2 days after dosing. The resulting LD50 is 383 mg/kg bw, corresponding to 38 mg/kg bw for the submission substance only. Based on the low concentration of the submission substance in the test material the study was considered not reliable.

Key information is derived from a study with the ligand TTP (Tris(methylphenyl) phosphite), which was subject to an oral acute toxic class study in rats by Read across:

Tritolyl phosphite (tris(methylphenyl) phosphite, TTP) was examined in an oral acute toxic class study in female rats according to recent guidelines and GLP at doses of 300 and 2000 mg/kg bw. The females of the group treated at 2000 mg/kg had to be killed for ethical reasons 1.5 or 3 hours after dosing. The animals of the 300 mg/kg bw groups survived until the end of the study period. They revealed no or only transient signs of toxicity (slightly ruffled fur, slight sedation up to the 3- or 5-hour reading). The body weight of these animals was within the range commonly recorded for this strain and age. The LD50 of this study for female rat was: 300 mg/kg bw < LD50 > 2000 mg/kg bw.

Dermal:

The test substance was subject to an acute dermal LD50 test on rabbits. Doses of 1000 to 2000 mg/kg were applied to intact skin under occlusive conditions for 24 hours. Deaths occured in all dose groups within 2 days after dosing. The LD50 is 1129 mg/kg bw, corresponding to 508 mg/kg bw for the submission substance only.

Justification for classification or non-classification

The test substance needs to be classified for acute oral toxicity category 4 and for acute dermal toxicity category 3 according to Regulation (EC) 1272/2008.