Zirconium zircon with encapsulated cadmium selenium sulphide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only nominal concentration given; no data about measured test substance concentration is given (in eluats); only a brief description of the test conditions is given.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Obtained from Dr. Knie LWA. Cultured at 20°C; separation of pups daily; age between 6 and 24 hours.

Test type:

static

Water media type:

freshwater

Test temperature:

20 +/- 1°C

pH:

7.40 - 7-59

Dissolved oxygen:

8.50 mg O2/L

Details on test conditions:

Tests were performed with the eluates of the following nominal test substance suspension concentrations (water soluble fraction of the test substance, filtered after 24 h stirring of each respective loading):
screening test: 10,000 mg, 1,000 mg, 100 mg, 10 mg, 1 mg and 0 mg test substance suspended in dilution water (OECD 202).
Main test: 10,000 mg, 8,000 mg, 4,000 mg, 2,000 mg and 1,000 mg

Exposure duration: 48 hr

Control: blank control

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

9 740 other: mg/L dissolved fraction

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

6 840 other: mg/L dissolved fraction

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

4 000 other: mg/L dissolved fraction

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

4 000 other: mg/L dissolved fraction

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Reported statistics and error estimates:

Calculations performed with Excel 5.0.

Conclusions:

A 48h-EC50 value for toxicity to daphnids of 6840 mg/L (based on dissolved fractions after 24 hours of stirring of 5 different loadings ranging from 1,000 - 10,000 mg/L, respectively) is obtained. This value is used in the risk assessment procedure.

Description of key information

The results of a key study with Zirconium zircon with encapsulated cadmium selenium sulphide indicate a low potential for acute toxicity to freshwater invertebrates. The respective 48 h EC50 of Zirconium zircon with encapsulated cadmium selenium sulphide on mobility of freshwater invertebrates (Daphnia magna), obtained in a test according to OECD 202, is estimated to be 6840 mg/L (based on dissolved fractions after 24 hours of stirring of 5 different loadings ranging from 1,000 - 10,000 mg/L, respectively) (Weyand, 2000). Nevertheless, read-across to the assessment entity soluble cadmium substances is applied since cadmium cations determine fate and toxicity in the environment.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

based on dissolved fractions after 24 hours of stirring of 5 different loadings ranging from 1,000 - 10,000 mg/L, respectively

Effect concentration:

6 840 mg/L

Additional information

One reliable study (Klimisch 2) is available for the acute toxicity of the test item onDaphia magna. The value for mortality and immobilisation was determined to be 6840 mg pigment/L (based on dissolved fractions after 24 hours of stirring of 5 different loadings ranging from 1,000 - 10,000 mg/L, respectively).