Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Additional information

Justification for classification or non-classification

Acute toxicity:

Since no information is available regarding acute oral toxicity of trilithium orthophosphate, read-across has been performed to lithium chloride (CAS# 7447-41-8), representing another lithium salt; and to trisodium orthophosphate (CAS# 7601-54-9), representing another alkali phosphate.

Concerning this endpoint, the lithium ion is considered to be the main toxophore, as phosphate ions are widely distributed throughout the organism (e.g. as structural material of bone and teeth and in form of adenosine phosphates ADP and ATP).

With regard to the fact, that trilithium orthophosphate is slightly soluble in water (0.27 g/L), read-across to a more soluble lithium salt (representing a higher bioavailability) can be justified.

There is one study summary for acute oral toxicity with trisodium orthophosphate (CAS# 7601-54-9) publicly available on the ECHA (European Chemicals Agency) homepage. This study was performed according to OECD Guideline 420 and showed that the LD50 of trisodium orthophosphate is higher than 2000 mg/kg bw.

In a review article by Petersen (Acta Pharmacologica et Toxicologica 47, 351 - 354, 1980), the LD50 (male, oral route) for lithium chloride was determined to be 526 mg/kg bw.

Based on a weight of evidence approach, trilithium orthophosphate is classified as Xn, R22, harmful if swallowed in accordance to Directive 67/548/EEC; Acute Toxicity Cat. 4, H302, harmful if swallowed in accordance to EU CLP (Regulation (EC) No. 1272/2008) and UN GHS.