Fumes, silica

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

26 Oct. 1998 - 30 Oct. 1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study - but read-across

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

version 07 June 1984

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Automatically generated during migration to IUCLID 6, no data available

IUPAC Name:

Automatically generated during migration to IUCLID 6, no data available

Details on test material:

other Test Substance:
SIPERNAT 820A, sodium aluminium silicate (Degussa) [CAS No. 1344-00-9]

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: ca. 1700 °C
- Boiling point: not relevant
- Vapour pressure: practically 0 Pa
- Water solubility (under test conditions): 48 mg/L (Sum of SiO2, Al, Na)
- Henry's law constant: not applicable
- log Pow: not applicable
- pKa: no data
- Stability in water: stable
- Stability in light: stable
- pH dependance on stability:


OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: not applicable

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: stirring the suspensions for 24 h in 0.5 l ultrapure water, followed by filtration through paper filter.
- Eluate: Water extracts from 6250, 630, and 60 mg silicate/0.5 L, diluted to the target concentration
by additions of stock solutions needed for testing.
- Differential loading: yes
- Controls: without or with respective filtrates, but without algae
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): none
- Evidence of undissolved material (e.g. precipitate, surface film, etc): not specified

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: CHODAT
- Source (laboratory, culture collection): Pflanzenphysiol. Inst. University of Göttingen/Germany
- Age of inoculum (at test initiation): see below
- Method of cultivation: preculture 3 days prepared before test from a stock culture

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

none

Test conditions

Hardness:

not specified

Test temperature:

24.9 +-0.3°C

pH:

Initial pH: 8.00 (control); between 8.12 and 8.58 (tests)
final pH: 10.74 - 10.76

Dissolved oxygen:

-

Salinity:

not applicable

Nominal and measured concentrations:

96, 1008, and 10,000 mg/L nominal

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: 50 ml glass cylinders
- Aeration:
- Renewal rate of test solution (frequency/flow rate): none
- Initial cells density: approx. 8 x10^4/ml
- Control end cells density: 2.83 x10^6/ml
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 7 (algal growth control), 3 (TS controls without algae)


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic medium from ultrapure water
- Total organic carbon: no data
- Alkalinity: not specified
- Ca/Mg ratio: not specified
- Conductivity: not specified



OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous
- Light intensity and quality: approx. 8000 lux [>= 120 µE/(m2*sec)]


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer at 578 nm after 24, 48, and 72 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Remarks on result:

other: NOELR = No-observed effective loading rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Details on results:

- Exponential growth in the control (for algal test): yes,
After 72 h, an increase in biomass (cell numbers) at a factor of >30 was achieved at any concentration.

- Observation of abnormalities (for algal test): no particular findings specified

- Any stimulation of growth found in any treatment: slight stimulation rather than inhibition observed

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

not applicable

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the test conditions, the test substance exhibited no acute and chronic toxic effect towards the test system (Scenedesmus subspicatus CHODAT).