Aluminium ammonium bis(sulphate)

Long-term toxicity to fish

Description of key information

Reliable data are available for read across on the two products of dissociation of AlNH4(SO4)2: ammonium sulfate at pH 6.3-6.5 and aluminium sulfate at pH 5.6-6.6. The greatest sensitivity was shown in a 60d early life stage test with Al(SO4)2 giving a NOEC (60d)= 0.015 mg/l Dissolved Al (=0.068 mg/L total Al), converted into 1.14 mg/L AlNH4(SO4)2.12H2O.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.14 mg/L

Marine water fish

Marine water fish

Effect concentration:

1.14 mg/L

Additional information

Aluminium ammonium sulfate instantaneously dissociates in water in its two components salts: aluminium sulfate and ammonium sulfate. Therefore, the hazard of aquatic environment of these aluminium salts can be assessed by effects of its dissociation products.

Ammonium sulfate

For freshwater fish, six studies on four species are reported in the OECD SIDS for ammonium sulfate (2004). The greatest sensitivity was shown by alevins of Oncorhynchus gorbuscha before complete yolk absorption, with effects on the length and weight of fry at migration seen at a LOEC (61 d) of 2.4 µg/L NH₃and 128 mg/LAlNH4(SO4)2.12H2O and at pH of 6.3-6.5. The associated NOEC (61 d) is 1.2 µg/L NH₃and 64 mg/LAlNH4(SO4)2.12H2O (Rice and Bailey, 1980). Five test performed on three other freshwater species show lower toxicity including exposure from 10 days to 12 months at pH between 7 and 7.3.

Aluminum sulphate

Two reliable long-term studies are available on aluminium sulfate. The key study (Cleveland et al, 1989), is a 60 days Early-life-stage semi-static test with Salvelinus fontinalis at a pH of 5.6 -6.6. The results gave a NOEC of 0.015 mg/l Dissolved Al or 1.14 mg/L AlNH4(SO4)2.12H2O. An another study, (Cleveland et al, 1991) exposing 30 days old Salvelinus fontinalis to nominal aluminum concentrations of 200µg/L for 56 days at pHs of 5.0, 6.0 and 7.2 is used as supportive information because no effect endpoint were derived from the results. However, it could be estimated that 0.150 <EC50< 0.216 mg/L Total Al or 2.52< EC50< 3.63 mg/L AlNH4(SO4)2.12H2O at pH 5.3; 0.146 <EC50< 0.288 mg/L Total Al or 2.45< EC50< 4.84 mg/L AlNH4(SO4)2.12H2O at pH 6.1 and EC50> 0.172 mg/L Total Al or EC50> 2.89 mg/L AlNH4(SO4)2.12H2O at pH 7.2. These results are in line with the key study performed on the same species.

From these results it can be concluded that in the pH range of 5.6 -6.5, the chronic toxicity of AlNH4(SO4)2.12H2O is drove by the toxicity of aluminium and the higher effect was found after 60d of exposure to Al₂(SO₄)₃on the weight of juvenile giving a NOEC (60d) corresponding to 1.14 mg/L AlNH4(SO4)2.12H2O.