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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
7 days
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Principles of method if other than guideline:
A one-week toxicity test with young Hyalella, including feeding, was used because 48-h acute tests without food are difficult to conduct with young Hyalella, which swim and stick to the surface if not fed.
GLP compliance:
not specified
Specific details on test material used for the study:
Most experiments were conducted using atomic absorption standards containing 1 g metal/. For zirconium, this was obtained from Sigma-Aldrich (Oakville, ON, Canada);
Test organisms (species):
other aquatic crustacea: Hyalella azteca
Details on test organisms:
Hyalella used for toxicity tests originated from Valens Conservation Area (ON, Canada), in 1985.
initial age of the test animals 1 to 11 d at the start of the test
Test type:
static
Water media type:
freshwater
Total exposure duration:
7 d
Hardness:
Tap water: dechlorinated Burlington City tap (Lake Ontario, Canada) water (hardness 124 mg/L)
Soft water: 10% tap water and 90% Milli-Qt (Millipore, Bedford, MA, USA) deionized water (hardness 18 mg/L)
Test temperature:
24-25 deg C
pH:
Tap water: 8.39 (Range 8.09–8.84)
Soft water: 7.39 (Range 6.44–8.52)
Details on test conditions:
16:8-h light:dark photoperiod
Tests were conducted in 400 ml of test water in 500-ml polyethylene cups (snap-top specimen containers).
2.5-mg Tetra-Min (Ulrich Baensch, Melle, Germany) fish food flakes were added to each container, followed by addition of 15 young
Hyalella. Test containers were not aerated during the test. An additional 2.5 mg of food was provided midweek.
Duration:
7 d
Dose descriptor:
LC50
Effect conc.:
> 1 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks on result:
other: soft water
Duration:
7 d
Dose descriptor:
LC50
Effect conc.:
> 3.15 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks on result:
other: tap water
Duration:
7 d
Dose descriptor:
EC50
Effect conc.:
ca. 8.5 mg/L
Nominal / measured:
nominal
Conc. based on:
other: Calculated for registered substance
Basis for effect:
mortality
Validity criteria fulfilled:
not specified
Conclusions:
The toxicity of zirconium to Hyalella azteca was measured as part of a study measuring the toxicity of 63 metals. Zirconium showed relatively low toxicity with LC50> 1 mg/L in soft water and > 3.15 mg/L in tap water.
The Zr 4+ content of the anhydrous registered substance is 37% suggesting a calculated EC50 8.5 mg/l
Executive summary:

The toxicity of zirconium to Hyalella azteca was measured as part of a study measuring the toxicity of 63 metals. Zirconium showed relatively low toxicity with LC50> 1 mg/L in soft water and > 3.15 mg/L in tap water.

The Zr 4+ content of the anhydrous registered substance is 37% suggesting a calculated EC50 8.5 mg/l

Description of key information

The toxicity of zirconium to Hyalella azteca was measured as part of a study measuring the toxicity of 63 metals. Zirconium showed relatively low toxicity with LC50> 1 mg/L in soft water and > 3.15 mg/L in tap water.

The Zr 4+ content of the anhydrous registered substance is 37% suggesting a calculated EC50 8.5 mg/l

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
8.5 mg/L

Additional information