Aluminium dihydrogen triphosphate

Long-term toxicity to aquatic invertebrates

Description of key information

NOEC (21 d): 1.5 mg/L (nominal), read across

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.5 mg/L

Additional information

Experimental results on the chronic 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 long-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 long-term toxicity testing is not feasible due to the low water solubility of aluminium dihydrogen triphosphate (MOE, 2003).

One report for aluminium dihydrogen triphosphate is available from MOE (2004). The solubility of the test substance in Elendt M4, the breeding water (dilution water), was at or below the limit of detection (0.052 mg/L) and the test substance was also poorly soluble in auxiliaries with weak reproductive toxicity (methanol, DMF, DMSO, acetone etc.). Thus a preparation of test solution by dissolution or homogeneous dispersion was considered difficult. Therefore long-term toxicity testing was deemed not possible since a proper confirmation of the test substance concentration would not have been possible.

The assessment of the chronic toxicity was therefore based on the available chronic toxicity test on the read across substance aluminium metaphosphate (CAS 13776-88-0). 

The study on the chronic toxicity of aluminium metaphosphate was conducted according to OECD guideline 211 (Simon, 2016). Daphnia magna was exposed to nominal test substance concentrations of 0.096, 0.24, 0.60, 1.50, and 3.75 mg/L. The aluminium concentrations in the test solutions were determined analytically. The mean measured aluminium concentrations were 0.21, 0.96, 2.87, 7.09 and 18.9 µg/L. During the exposure period of 21 days effects on survival, growth and reproduction of Daphnia magna were recorded. Based on the reproduction a NOEC of 1.5 mg/L (nominal test substance concentration) was observed.