Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Aluminum zirconium chloride hydroxide is an inorganic substance which will rapidly dissociate into aluminum, zirconium, chloride and hydroxide ions upon dissolution in the environment. However, zirconium ions will not remain as such in solution, and the environmental toxicity (if any) will not be driven by zirconium. Therefore, full read-across to other aluminum substances considering a typical aluminum content of ca. 19.4%  is justified. The lowest reliable EC10 and EC50 values of 0.051 mg/L and 0.24 mg/L dissolved aluminum derived in a static 72-h growth inhibition test with Pseudokirchneriella subcapitata are recalculated and result in a EC10 and EC50 of 0.263 mg/L and 1.237 mg/L aluminum zirconium chloride hydroxide, respectively.

Key value for chemical safety assessment

EC50 for freshwater algae:
1.237 mg/L
EC10 or NOEC for freshwater algae:
0.263 mg/L

Additional information

Aluminum zirconium chloride hydroxide is an inorganic substance which will rapidly dissociate into aluminum, zirconium, chloride and hydroxide ions upon dissolution in the environment. However, zirconium ions will not remain as such in solution. Thus, regarding the environmental fate and toxicity of Aluminum zirconium chloride hydroxide, it can be assumed that environmental fate and toxicity (if any) will not be driven by zirconium. Therefore, full read-across to dialuminum chloride pentahydroxide (CAS #12042-91-0) and other aluminum substances considering a typical aluminum content of ca. 19.4% is justified (see below).

One study with the fresh water green algaeChlorella pyrenoidosa with aluminum chloride is available. The author determined EC30 values, which cannot be used in the assessment. The EC10 (at pH 5) was determined by linear regression by the reviewer based on nominal concentrations, available in the article. The EC10 is 84 µg/l (dissolved Al). Another study with the fresh water green algaePseudokirchneriella subcapitatawith aluminum chloride hydroxide sulfate is available. The test was static and performed at a neutral pH between 7.1 and 8.1 at the start of the test to 8.0 and 8.4 at the end of the test. The nominal test concentrations were between 1.0 and 100 mg/l test material. This resulted in a range of dissolved aluminum concentrations of 0.02 to 2.8 mg/l.