Flue dust, zinc-refining

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Tests done according to standard protocol. Good quality and considered useful for setting the reference value for acute aquatic ecotoxicity. Culture medium, test water conditions well described and relevant the purpose of classification.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

yes

Remarks:

the test was performed with an algae suspension of 1x10 to the 4th at the start

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Flue dust, zinc-refining

EC Number:

273-760-6

EC Name:

Flue dust, zinc-refining

Cas Number:

69012-63-1

Molecular formula:

Not applicable - UVCB

IUPAC Name:

Zinc oxide enriched flue dust

Constituent 2

Reference substance name:

flue dust , zinc refining

IUPAC Name:

flue dust , zinc refining

Details on test material:

zinc compounds >50%
lead compounds 5-10%
cadmium compounds < 0.25%

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

samples were taken at the beginning and the end of the test

Test solutions

Vehicle:

no

Details on test solutions:

according to OECD 201. The test was performed on a "water soluble fraction" according to the OECD series on testing and assessment Number 23, : "Guidance document on aquatic toxicity of difficult substances and mixtures".
The water soluble fractions were prepared by stirring nominal loadings of 100mg/l, 50mg/l, 25 mg/L , 12,5mg/l, 6.25mg/l, 3.13mg/L, 1.56mg/l and 0.78mg/l of waelz oxide in bidistilled water for 24hrs. After settling for 1hr, tyhe "water accommodated fraction" was taken from the middle of the solution, and filtered over a 0.2µm cellulose-acetate filter to get the "water soluble fraction". This was used in the test.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Organisms originated from the Umweltbundesambt in Berlin-Marienfelde, D.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22.8-23.7°C

pH:

7.4-7.9

Nominal and measured concentrations:

nominal loadings of 50, 12.5 and 3.13mg/l resulted at end of the test in concentrations of 1290, 1410, 693 µg Zn/l, 12, 5, 4 µg Pb/l and 22, 5, 2 µg Cd/l, resp.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

16.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 6.3-52.4 mg/l

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: nd-1.5mg/l

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: "yield"

Remarks on result:

other: 95% CI: 0.5-3.4mg/l

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.05 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: "yiled"

Remarks on result:

other: 95 % CI : nd-0.25mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Tests done according to standard protocol. Good quality and considered useful for setting the reference value for acute aquatic ecotoxicity.

Executive summary:

Test according to OECD 201 resulted in an EC50 value for Waelz zinc oxide of 16.2 mg/l for specific growth rate, and 1.8 mg/l for "yield" ("yield" is "biomasse-Ertrag"). According to TGD part 2, (2003), the endpoint specific growth rate is used for the classification.