BRUGGOLITE® FF6

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Melting point: no melting point/range (Decomposition at temperatures > 200 °C)
- Boiling point: no boiling point (decomposition before boiling)
- Vapour pressure: <1 * 10-12 hPa at 25°C (calculation)
- Water solubility: 125.76 g/L at 20°C
- log Pow: <-2
- pKa: = 7,00+/-0,04

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 50, 100, 1250, 2500, 500, 10000 mg/L,

Vehicle:

no

Details on test solutions:

The Test article is a well soluble powder with strongly reduginc properties. This would lead to total oxygen depletion in the test flasks and consequent growth inhibition. According to former tests with the test item, the test article was solved in deionized water and aerated with cleaned compressed air for 24 hours at 20°C until complete oxidation. The test concentrations were produced by diluting the stock solution with test water.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Scenedesmus subspicatus SAG 86.81, Chlorophyceae, Chlorococales
-stock culture/method of cultivation: on a sterile sloped agar tube (OECD mdium, 0.8% Agar), transfer to a new agar tube every 2 month
-pre-culture: Incubation on a shaker in 250 mL Erlenmeyer flasks, sterile, ca 72 h, 25°C, 100-130 rpm, 10000 lux, permanent illumination

ACCLIMATION
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

no observation period given in the study

Hardness:

no hardness indicated in the study

Test temperature:

25° C +/- 2°C, climated room

pH:

8

Dissolved oxygen:

no data available

Salinity:

see "details on test conditions": Solution 1, 2, 3 and 4

Nominal and measured concentrations:

nominal concentrations: 50 - 100 - 1250 - 2500 - 5000 - 10000 - Control [mg/L]
measured concentrations: no data available

Details on test conditions:

TEST SYSTEM
- Initial cells density: approx. 10000 cells/mL
- Control end cells density: 1055107 cells/mL (average of control 1,2 and 3 after 72 h)

TEST MEDIUM / WATER PARAMETERS

The Test article is a well soluble powder with strongly reducing properties. This would lead to total oxygen depletion in the test flasks and consequent growth inhibition. According to former tests with Bruggolite FF6 the test article was solved in deionized water and aerated with cleaned compressedair for 24 hours at 20°C until complete oxidation. The test concentrations were produced by diluting the stock solution with test water.

preparation of:

Solution 1 (according to OECD 201):
- NH4Cl (1.5 g/L)
- MgCl2 x 6 H2P (1.2 g/L)
- CaCl2 x 2 H2O (1.8 g/L)
- MgSo4 x 7 H20 (1.5 g/L)
- KH2Po4 (0.16 g/L)

Solution 2:
- FeCl3 x 6 H2O (0.08 g/L)
- Na2 EDTA x 2 hso (0.1 g/L)

Solution 3:
- H3BO3 (0.185 g/L)
- MnCl2 x 4 H2= (0.415 g/L)
- Na2MoO4 x 2 H2= (0.0007 g/L)
- Zncl2 (30 mL stock solution), stock solution with C= 100 mg/L
- CoCl2 x 6 H2O (15 mL stock solution), stock solution with C= 100 mg/L
-CuCl2 x 2H2O (100 µL stock solution), stock solution with C= 100 mg/L

Solution 4:
- NaHCo3 (50.0 g/L)

the medium is made up with water an is autoclaved at 121 °C for 15 minutes. Solution 4 is added by sterile filtration (0.45 µm pore size).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment of pH
- Light intensity and quality/Illumination: ca. 10 000 Lux, permanent illumination


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chambers (Fuchs-Rosenthal: chamber factor 80000, Neubauer: chamber factor 4000000)
- Spectrophometer 662, Methrom
- measurement of the optical density at 520 nm ath the times 24, 48 and 72 h and calculation of the cell concentration (per mL). The average of the cell concentrations is plotted against the time to obtain the growth curve.

TEST CONCENTRATIONS
- Test concentrations: 50, 100, 1250, 2500, 5000, 10000 mg/L

Reference substance (positive control):

no

Duration:

72 h

Dose descriptor:

other: EbC50

Effect conc.:

300 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

315 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Test concentrations of 50 and 100 mg/L caused moderate inhibition of algae growth after 72 h. The test concentrations 1250, 2500, 5000 and 10000 mg/L resultet in total inhibition after 72 h.

Results with reference substance (positive control):

no reference substance (positive control) was tested.

Reported statistics and error estimates:

no data available

Validity criteria fulfilled:

yes

Conclusions:

The test item is not acute toxic to Algae.

Executive summary:

the substance is not acute toxic to Algae.

EbC₅₀ (72h)= 300 mg/l;

ErC₅₀( 72h) = 315 mg/l

Description of key information

the substance is not acute toxic to Algae.
EbC50 (72h)= 300 mg/l;
ErC50( 72h) = 315 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

300 mg/L