Chrome antimony titanium buff rutile

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

no analysis of test concentrations; the dissolved fraction of the test material used for the preparation of test solutions was established by stirring the test material for only 20 hours

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

1992

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.5400 (Algal Toxicity, Tiers I and II) (January 2012)

Version / remarks:

1996

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Chrome antimony titanium buff rutile

EC Number:

269-052-1

EC Name:

Chrome antimony titanium buff rutile

Cas Number:

68186-90-3

Molecular formula:

(Ti, Sb, Cr) O2

IUPAC Name:

manganese(4+) trititanium(4+) pentaantimony(3+) chromium(3+) nickel(2+) octadecaoxidandiide

Test material form:

solid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method:
The test was performed with an aqueous extract (filtrate) of the test substance (water solubility < 1 mg/L). The test substance was stirred in demineralized water for ca. 20 h at 20°C. Undissolved test substance was removed by membrane filtration (pore size 0.2 µm). The nominal concentration of the filtrate was 125 mg/L. Further dilution led to the nominal concentrations: 100, 50, 25, 12.5, 6.25, 3.13, 1.56 mg/L.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: Scenedesmus subspicatus CHODAT SAG 86.81
- Source (laboratory, culture collection): The test strain of Scenedesmus subspicatus CHODAT SAG 86.81 is obtained at regular intervals from SAG (Collection of algal cultures in Göttingen) and is kept in liquid culture in the Laboratory of Ecology at BASF AG Ludwigshafen.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

23 ± 2°C

pH:

pH values in uninoculated tests 7.8 - 7.9 at start of experiments and 7.9 after 72 h, in inoculated tests pH 7.6 - 7.8 after 72 h

Nominal and measured concentrations:

Nominal concentrations: control, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL Erlenmeyer flasks plugged with silicon sponge caps; test volume 100 mL
- Initial cells density: 10000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
The test medium was prepared according EEC Directive 92/69/EEC, Annex V, Part C.3. Algal inhibition test, updating 29 December 1992 and OECD Guideline for Testing of Chemicals, No. 201 Algal growth inhibition test, June 1984.

OTHER TEST CONDITIONS
- Photoperiod: permanent illumination
- Light intensity and quality: artificial light, type universal white (e.g. OSRAM L 25), about 60 - 120 µE/(m2*s) at a wave length of 400 - 700 nm


EFFECT PARAMETERS MEASURED:
1) in vivo chlorophyll-a-fluorescence at 435 nM wavelength after 0, 24, 48, 72 h
2) control culture: additionally cell counting after 72 h in a counting chamber

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Results with reference substance (positive control):

Positive control was performed with potassium dichromate: EC50, 72 h was 0.41 mg/L.

Reported statistics and error estimates:

The EC values were calculated by linear regression analysis from dose-response relationship. The NOEC and LOEC were calculated using Duncan multiple range test at 95% significance level.

Any other information on results incl. tables

Cell multiplication factor of the negative control after 72h: 149-fold

Inhibition of algal biomass after 72h:

Concentration test substance [mg/L]	Inhibition [% of control]
0	0
1.56	-1.6
3.13	-4.5
6.25	-1.4
12.5	0.5
25	-1.0
50	1.0
100	-15.4

 

 

Inhibition of algal growth rates after 72h:

Concentration test substance [mg/L]	Inhibition [% of control]
0	0
1.56	-0.7
3.13	-2.0
6.25	0.1
12.5	-0.3
25	-2.3
50	-1.0
100	-4.0

Applicant's summary and conclusion

Conclusions:

Dissolved fractions of chrome antimony titanium buff rutile are not toxic to the freshwater algae Desmodesmus subspicatus in a test according to OECD 201 with dissolved fractions prepared at nominal concentrations far exceeding its water solubility. The corresponding EC50 and EC10 for growth inhibtion are both estimated with > 100 mg/L (nominal). As the study was conducted according to a previous version of the guideline (OECD 201), section-by-section specific growth rates were not determined. Since the dissolved fraction for the preparation of test solutions was prepared by stirring the test substance for only 20 hours and no chemical analysis was performed, the reliability of the study is rated RL3.