Aluminium dihydrogen triphosphate

Short-term toxicity to aquatic invertebrates

Description of key information

EC50  (48 h) > 100 mg/L , (nominal), read across

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Experimental results on the acute toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) to aquatic invertebrates are not available. The assessment is therefore based on an expert statement regarding the feasibility of a short-term toxicity study and on read-across data. In accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across to the structurally related Aluminium metaphosphate (CAS 13776-88-0) was conducted to fulfil the standard information requirements. In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for aquatic toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across). According to Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 substances can be considered to be similar if their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. For further details please see chapter 6.1 of the IUCLID file.

According to the expert statement a test on the toxicity of aluminium dihydrogen triphosphate to Daphnia magna is not feasible due to the low water solubility of the test substance (MOE, 2003). Although the test substance was sparingly soluble in water, it dissolved to some extent, whereupon it dissociated mainly to the triphosphate (tripolyphosphate), diphosphate (pyrophosphate) and monophosphate (ortho-phosphate), etc. These were measured by analysis from MOE. However, the solubility of the test substance in the rearing solution (dilution water) Elendt M4 was below the detection limit (0.052 mg/L). The test substance is also only sparingly soluble in weakly ecotoxic auxiliary agents (methanol, DMF, DMSO, acetone, etc.), and so it was deemed very difficult to prepare a test solution in which the test substance would be dissolved or uniformly dispersed. It was therefore deemed impossible to perform a study of acute inhibition of freshwater flea swimming under normal conditions, because the solubility of the test substance in the dilution water used was unknown and an accurate confirmation of the substance concentrations would not have been possible.

The acute assessment is therefore based on the available short-term toxicity test on the read across substance aluminium metaphosphate (CAS 13776-88-0). The acute toxicity of aluminium metaphosphate to invertebrates was investigated in a study by Simon (2014). This test was conducted according to OECD 202 under GLP conditions. Test organisms (Daphnia magna) were exposed to the test substance for 48 hours, applying a static water regime. Analytical determinations were performed to ensure a proper maintenance of the test concentration throughout the experiment. No effects on immobilization or fitness of Daphnia magna were reported and therefore, an EC50 > 100 mg/L (> 0.245 mg/L measured aluminium) and a NOEC ≥100 mg/L (≥ 0.245 mg/L measured aluminium) were determined.

Thus, based on the available data aluminium dihydrogen triphosphate (CAS 13939-25-8) is considered not acutely toxic to aquatic invertebrates.