Aluminium tris(dihydrogen phosphate)

Endpoint summary

Additional information

Data on the aquatic toxicity of aluminium tris(dihydrogen phosphate) (CAS 13530-50-2) 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), aluminium dihydrogen triphosphate (CAS 13939-25-8), Aluminium sulphate-14-hydrate (CAS 16828-12-9), and Aluminium metaphosphate (CAS 13776-88-0) and Tripotassium trihydrogen diphosphate dehydrate (CAS 66922-99-4) 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 tris(dihydrogen phosphate) (CAS 13530-50-2). Ecotoxicological studies are conducted in aquatic medium or in moist environments; and as aluminium orthophosphates (such as aluminium tris(dihydrogen phosphate)) will dissociate in their ionic forms in water (Al3+ and PO43- ions which will further associate with the ionic forms of H2O, it is justified to assess the toxicity of the Al3+ ion and the PO43- ion as separate entities. Further information on the read across substances is given in the read-across justification in 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 13530-50-2	Aluminium tris(dihydrogen phosphate)	RA CAS 16828-12-9, RA CAS 66922-99-4	Expert statement	RA CAS 16828-12-9, RA CAS 66922-99-4	Expert statement	RA CAS 66922-99-4	RA CAS 7784-30-7
Source 1 CAS 16828-12-9	Aluminium sulphate-14-hydrate	Experimental result:LC50 >1000 mg/L	--	Experimental result:EC50 >160 mg/L		--	--
Source 2 CAS 10043-01-3	Aluminium sulphate-16-hydrate	--	Experimental result: NOCE, (60d) 0.07 mg/L (Total Al)	--	--	--	--
Source 3 CAS 66922-99-4	Tripotassium trihydrogen diphosphate dehydrate	Experimental result:LC50 >100 mg/L	--	Experimental result:EC50 >100 mg/L	--	Experimental result:EC50 >100 mg/L	--
Source 4 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	--
Source 5 CAS 7784-30-7	Aluminium orthophosphate	--	--	--	--	--	Experimental result: NOEC (3 h) ≥1000mg/L,

 

Aquatic toxicity and microorganisms

Experimental data on the short-term toxicity to fish, daphnia and algae of aluminium tris(dihydrogen phosphate) (CAS 13530-50-2) are not available. The assessment is therefore based on the available acute toxicity studies on the read across substances aluminium sulphate-14-hydrate (CAS 16828-12-9) and tripotassium trihydrogen diphosphate dehydrate (CAS 66922-99-4).

The acute toxicity of tripotassium trihydrogen diphosphate dehydrate to fish was investigated in a study according to OECD 203 under GLP conditions. A LC50 above 100 mg/L and a NOEC ≥100 mg/L were determined. Aluminium sulphate-14-hydrate (CAS 16828-12-9) was tested under semi-static conditions for 96 hours. No mortality was observed up to the highest test concentration. Thus, a LC50 > 1000 mg aluminium sulphate-14-hydrate / L (nominal) was determined. 

The acute toxicity of tripotassium trihydrogen diphosphate dehydrate and aluminium sulphate-14-hydrate to aquatic invertebrates was tested in guideline studies according to OECD 202 and GLP. Both studies recorded no adverse effects of the test substances on Daphnia magna up to the highest tested concentration. An EC50 > 100 mg/L was determined for tripotassium trihydrogen diphosphate dehydrate. For aluminium sulphate-14-hydrate a NOEC >160 mg/L was reported.

The toxicity of phosphoric acid, potassium salt (2:3) dihydrate (CAS 66922-99-4) to algae was investigated in one study according to OECD 201. No effects on algae yield or growth rate were reported at the end of the experiment, leading to an EC50 above 100 mg/L and a NOEC ≥100 mg/L.

Experimental data on the long-term toxicity of aluminium tris(dihydrogen phosphate) (CAS 13530-50-2) to fish and aquatic invertebrates are not available. The assessment is therefore based on the available chronic toxicity studies on the read across substances Aluminium sulphate hexandecahydrate (CAS 10043-01-3) and Aluminium metaphosphate (CAS 13776-88-0).

 

The chronic toxicity of aluminium sulphate hexandecahydrate (CAS 10043-01-3) to fish was investigated in a study on (sub)lethal effects on Pimephales promelas. Hatched fry were exposed to the substance for 28 days in a flow-through system. The exposure concentrations were 2.32-53.81 mg/L. NOECs and LOECs were determined for mortalities of the fry, weight, length, and number hatched. Based on the measured total Al NOECs were in the range of 4.7 to 23.1 mg/L and LOECs in the range of 7.1 to 53.8 mg/L.

The long-term toxicity of aluminium metaphosphate to aquatic invertebrates was tested in a study following 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.

 

Measured data on the toxicity to microorganisms are not available for aluminium tris(dihydrogen phosphate). The assessment is therefore based on read across data for aluminium orthophosphate (CAS 7784-30-7). The study was performed according to OECD 209. The determined EC50 (3 h) was > 1000 mg/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was ≥ 1000mg/L.

Based on the available read across data toxic effects of aluminium tris(dihydrogen phosphate) (CAS 13530-50-2) to aquatic organisms are not anticipated.