Aluminium metaphosphate

Endpoint summary

Additional information

Data on the acute toxicity of aluminium metaphosphate (CAS 13776-88-0) are available for all three trophic levels (fish, Daphnia, algae). All available studies were performed according to internationally accepted guidelines and under GLP.  Due to the low water solubility of aluminium metaphosphate the test solutions were prepared using the Water Accommodated Faction (WAF) approach according to the OECD guidance documents No. 23 and 29. Furthermore the aluminium concentration of the single test solutions was monitored analytically throughout the tests.

The short-term toxicity to fish was determined in an OECD 203 guideline study. No mortality or any symptoms were observed after 96 hours. The resulting LC50 was >100 mg/L based on the nominal test substance concentration (LC50>0.156 mg Al/L (mean measured aluminium concentrations)). A comparable result was determined for aquatic invertebrates in a study following OECD 202 (GLP). Daphnia magna were exposed for 48 hours under static conditions.  No effects on the test animals were observed and therefore, an EC50 > 100 mg/L (nominal) and a NOEC ≥100 mg/L (nominal) were reported. Based on the mean measured aluminium concentrations the effect concentrations were EC50> 0.245 mg Al/L (mean measured concentration) and NOEC≥ 0.245 mg Al/L (mean measured concentration). Furthermore no inhibition of algal growth was observed in an experimental study according to OECD 201 (GLP).  Based on the algal growth an EC50 (72 h) value >100 mg/L (nominal) and a NOEC ≥100 mg/L (nominal) were determined. Based on the mean measured aluminium concentrations the effect concentrations were EC50> 15 µg Al/L (mean measured concentration) and NOEC ≥ 15 µg Al/L (mean measured concentration).

The chronic toxicity of aluminium metaphosphate (CAS 13776-88-0) was investigated 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.

Data on the toxicity of aluminium metaphosphate (CAS 13776-88-0) to microorganisms are not available. In accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across to the structurally related substance aluminium orthophosphate (CAS 7784-30-7) 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 substance is considered suitable to read-across to aluminium metaphosphate (CAS 13776-88-0). 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 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
Source 1 CAS 7784-30-7	Aluminium orthophosphate	--	--	--	--	--	Experimental result: NOEC (3 h) ≥1000mg/L

The study on the source substance aluminium orthophosphate (CAS 7784-30-7) 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.

Based on the available information the target substance aluminium metaphosphate (CAS 13776-88-0) is considered not acutely or chronically toxic to aquatic organisms under environmental conditions.