Aluminium dihydrogen triphosphate

Endpoint summary

Additional information

Data on the aquatic toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) are not available In accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across to the structurally related substances aluminium orthophosphate (CAS 7784-30-7) and 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.

Due to the structural similarities and consistent trend in physico-chemical, ecotoxicological, behaviour, the selected source substances are considered suitable to read-across to aluminium dihydrogen triphosphate (CAS 13939-25-8). Further information on the read across substances is given in the read-across justification (chapter 13 of the IUCLID file).

Data matrix: ecotoxicological properties

ID	Substance name	Short-term toxicity to fish	Long-term toxicity to fish	Short-term toxicity to Daphnia magna,	Long-term toxicity to Daphnia magna	Short-term toxicity to algae	Toxicity to microorganisms, 3h EC50 [mg/L]
Target CAS 13939-25-8	Aluminium dihydrogen triphosphate	Experimental result: LC50 (96 h) >0.327 mg/L (>100 mg/L nominal)   RA CAS 13776-88-0	waiving	Experimental result: substance was insoluble in test medium (Elendt M4)   RA CAS 13776-88-0	Experimental result: substance was insoluble in test medium (Elendt M4)   RA CAS 13776-88-0	Experimental result: EC50 (72 h) > 0.911 mg/L (> 100 mg/L nominal)   RA CAS 13776-88-0	RA CAS 7784-30-7
Source 1 CAS 7784-30-7	Aluminium orthophosphate	--	--	--	--	--	Experimental result: NOEC (3 h) ≥1000mg/L,
Source 2 CAS 13776-88-0	Aluminium metaphosphate	Experimental result:LC50 (96 h) >100 mg/L	--	Experimental result:EC50 (48 h) >100 mg/L	Experimental result: NOEC (21 d): 1.5 mg/L	Experimental result:EC50 (72 h) >100 mg/L	RA CAS 7784-30-7

Experimental data on the acute toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) are available for fish and algae. Furthermore two expert statements on the feasibility of short- and long-term toxicity studies on Daphnia are available for the substance. Both expert statements conclude that the studies cannot be performed. The conclusion is explained by the unknown solubility of the test substance in the dilution water and a lacking possibility to confirm the test substance concentration.

The acute toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) to fish was investigated in two studies. One study of acute toxicity in Gold Medaka (Oryzias latipes) was conducted according to OECD 203 (MOE, 2003) under semi-static conditions. There were no effects on survival up to the solubility of the test substance in test medium (96 hour LC50 > 0.327 mg/L (100 mg/L nominal).The second semi-static study with Gold Medaka (Oryzias latipes) from METI (2001) also shows no toxicity up to the tested nominal concentration of 250 mg/L. The acute toxicity of the source substance aluminium metaphosphate (CAS 13776-88-0) to fish was tested in a study following OECD 203 (Simon, 2015). A LC50 (96 h) value >100 mg/L (nominal) was determined. The acute toxicity of the source substance aluminium metaphosphate (CAS 13776-88-0) to Daphnia magna was determined in a study following OECD 202. After an exposure period of 48 hours an EC50 > 100 mg/L (> 0.245 mg/L measured aluminium) was reported (Simon, 2014).

One study report for Aluminium dihydrogen triphosphate to algae is available (MOE, 2003). The study was conducted according to OECD guideline 201. The test was terminated after 72 hours and an EC50 > 0.911 mg/L (the highest tested concentration) based on the algal growth rate was determined. An increase in the algal growth rate at lower substance concentrations was attributed to the increased availability of phosphate compared to the control. For the source substance aluminium metaphosphate (CAS 13776-88-0) and EC50 (72 h) value >100 mg/L (nominal) and a NOEC ≥100 mg/L (nominal) were determined (Wenzel, 2014).

Experimental data on the long-term toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) to aquatic organisms are not available. The assessment is therefore based on a long-term toxicity study conducted with the source substance aluminium metaphosphate (CAS 13776-88-0). The study followed OECD guideline 211 (Simon, 2016). Daphnia magna was exposed to the test substance for 21 days. At test termination a NOEC of 1.5 mg/L (nominal test substance concentration) based on the reproduction was determined.

Experimental data on the toxicity of aluminium dihydrogen triphosphate (CAS 13939-25-8) to microorganisms are not available. The assessment is therefore based on data available for the source substance aluminium orthophosphate (CAS 7784-30-7). The study was conducted according to OECD 209 (Clarke, 2010). The respiration of activated sludge was not inhibited by the substance and thus a EC50(3 h) > 1000 mg/L was reported. The No Observed Effect Concentration (NOEC) after 3 hours exposure was ≥ 1000mg/L.