Dilithium azelate

Endpoint summary

Description of key information

Based on the available data, the dilithium salts exhibit acute oral toxicity; with LD50 of 300-2000 mg/kg bw, the substances in the category meet the criteria for acute toxicity category 4.

 

No evidence of acute dermal toxicity was evident from the studies on dilithium adipate and dilithium sebacate and it can be concluded that the remaining category member, with a chain length between the two tested substances, is similarly devoid of classifiable acute dermal toxicity.

 

No acute inhalation toxicity testing has been conducted because the lithium salts of dicarboxylic salts C6 - C10 have vapour pressures of <1.3 x 10(-8) Pa at 20°C and are exclusively manufactured in situ in base oil and the use of the grease forms will not result in aerosols, particles or droplets of an inhalable size.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

discriminating dose

Value:

300 mg/kg bw

Quality of whole database:

High. Reliable, adequate and relevant data available to fulfil the tonnage-driven data requirements of REACH. Data are available for every substance in the lithium salts of dicarboxylic acid C6-C10 category.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

No acute inhalation toxicity testing has been conducted because the lithium salts of dicarboxylic salts C6 - C10 have vapour pressures of <1.3 x 10(-8) Pa at 20°C and are exclusively manufactured in situ in base oil and the use of the grease forms will not result in aerosols, particles or droplets of an inhalable size.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

High. Reliable, adequate and relevant data available to fulfil the tonnage-driven data requirements of REACH. Data are available for the shortest and longest chain length substance in the lithium salts of dicarboxylic acid C6-C10 category and the results have been read across to the substance with an intervening chain length.

Additional information

The substances in the category are considered to be similar on the basis that they have common structures of a lithium ion varying only by the length of the acid chain. As a result, it is expected that the substances will have similar, predictable properties. REACH Annex V, Entry 9, groups carboxylic acids and their potassium, sodium, calcium and magnesium salts, including C6 to C24, predominantly even-numbered, unbranched, saturated or unsaturated aliphatic monocarboxylic acids. Since published reviews do not distinguish between the properties of monocarboxylic or dicarboxylic acids as a category, then the same interpretation can be applied to the dicarboxylic acids and due to the close structural similarity and the narrow range of carbon chain numbers covered in this category, the acute toxicity potential is expected to be similar across the category. 

 

Key acute oral toxicity studies were performed on the three dilithium salts of adipic, azelaic and sebacic acids in the category. The results from the Fixed Dose acute oral toxicity studies performed according to OECD 420 guidelines were consistent across the category. One or more deaths were seen at 2000 mg/kg bw for each substance, whereas no mortality occurred at 300 mg/kg bw. Based on the mortality rate at 2000 mg/kg/bw, it was concluded that the oral LD50 values of the three members of the category were within the range of 300-2000 mg/kg bw. 

 

Key acute dermal toxicity studies were performed on the dilithium adipate and dilithium sebacate, the shortest and longest chain length substances in the category. The results from the Fixed Dose acute dermal toxicity studies performed according to OECD 402 guidelines were consistent between the substances tested and therefore the results have been read across to the remaining substance in the category. No deaths were seen at 2000 mg/kg bw for each substance and it was concluded that the dermal LD50 values of the three members of the category were >2000 mg/kg bw.

 

No acute inhalation toxicity testing has been conducted because the lithium salts of dicarboxylic salts C6 - C10 have vapour pressures of <1.3 x 10(-8) Pa at 20°C and are exclusively manufactured in situ in base oil and the use of the grease forms will not result in aerosols, particles or droplets of an inhalable size.

Justification for classification or non-classification

The oral LD50 values are within the range 300 mg/kg bw - 2000 mg/kg bw so the substances meet the criteria for acute oral toxicity category 4. 

 

The dermal LD50 values are >2000 mg/kg bw so the substances do not meet the criteria for acute dermal toxicity classification.