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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Study period:
Aug. 20, 1982-Sept. 13, 1982
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The studies are very well documented in this peer-reviewed publication and deserving of a reliability 2.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1986
Report Date:
1982
Reference Type:
publication
Title:
Unnamed
Year:
1986
Reference Type:
publication
Title:
A rapid method for determining the toxicity of chemicals to activated sludge
Author:
Larson, R.J. and S.L. Schaeffer
Year:
1982
Bibliographic source:
Water Res. 16: 675-680.
Reference Type:
publication
Title:
Predicted no-effect concentrations and risk characterization of four surfactants: Linear alkylbenzene sulfonate, alcohol ethoxylates, alcohol ethoxylated sulfates, and soap.
Author:
van de Plassche, E.J., de Bruijn, J.H.M., Stephenson, R.R., Marshall, S.J., Feijtel, T.C.J. and Belanger, S.E.
Year:
1999
Bibliographic source:
Environmental Toxicology and Chemistry. 18:2653-2663.

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Payne AG, Hall RH, 1979, in Aquatic Toxicology, ASTM, STP 667, pp. 171-180; and US EPA, 1978, The Selenastrum capricornutum Printz algal assay. Deviations, reliability, and validity will be evaluated using the USEPA OPPTS 850.5400 (1996) guideline.
Deviations:
no
Principles of method if other than guideline:
Standard Practice for Conducting Toxicity Tests with Microalgae, Draft #7, Philadelphia, PA.
Assumed 1 x 10^4 cells/mL because ASTM protocol, but not reported.

GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Linear Alkylbenzene Sulfonate(C11.9 LAS); LAS Sodium Salt; (X0235.01)
- Substance type: Pure active substance
- Physical state: A white paste

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution of X0235.01 was prepared by adding a weighed amount of test material to algal growth medium and other stock solutions were prepared by serial dilution. A growth medium control was conducted concurrently and contained no test material. All test concentrations, except 1,000 ppm, were prepared by pipeting 1.0 milliliter (ml) of the appropriate stock solution to each test flask.
- Eluate: Not applicable
- Differential loading: Not applicable
- Controls: AAP medium
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Not applicable
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): Not available
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: Green algae
- Strain: Not available
- Source (laboratory, culture collection): University of Texas at Austin, Austin, Texas
- Age of inoculum (at test initiation): Not available
- Method of cultivation: Not available

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

Study design

Test type:
other: static open-system
Water media type:
not specified
Limit test:
no
Total exposure duration:
96 h

Test conditions

Hardness:
Total mean water hardness was 137 mg/L as CaCO3.
Test temperature:
Mean test temperature was 23.6 (21.2-25.6 °C).
pH:
The pH range was 6.8 to 7.2.
Dissolved oxygen:
Mean dissolved oxygen was 9.1 mg/L.
Nominal and measured concentrations:
Nominal: 0, 16, 32, 63, 125, 250, 500, and 1000 mg/L first test
0.1, 1.0, 5.0, and 10 mg/L second test
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open / closed: Not available
- Material, size, headspace, fill volume: Test containers were 125-ml flasks with 50 ml solution
- Aeration: Not available
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- Renewal rate of test solution (frequency/flow rate): Not available
- Initial cells density: Both test 1 and test 2: 2x10(4) cells/ml
- Control end cells density: Test 1: 318x10(4); Test 2: 245x10(4)
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


GROWTH MEDIUM
- Standard medium used: Yes, AAP nutrient medium


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: AAP media prepared with deionized water
- Total organic carbon: Not available
- Particulate matter: Not available
- Metals: Not available
- Pesticides: Not available
- Chlorine: Not available
- Alkalinity: Not available
- Ca/mg ratio: Not available
- Conductivity: Not available
- Culture medium different from test medium: No
- Intervals of water quality measurement: Not available


OTHER TEST CONDITIONS
- Sterile test conditions: yes/no Not available
- Adjustment of pH: Not applicable
- Photoperiod: Not available
- Light intensity and quality: Approximately 2,000 lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Hemacytometer
- Cell counts were made on day 0,2,3,4,5.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2 (test 1). 2-10 (test 2).
- Justification for using less concentrations than requested by guideline: Not applicable
- Range finding study: no
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
29 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: cell density
Duration:
96 h
Dose descriptor:
NOEC
Effect conc.:
0.5 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: cell density
Duration:
96 h
Dose descriptor:
LOEC
Effect conc.:
1 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
other: cell density
Details on results:
- Exponential growth in the control (for algal test): Yes. Test 1 (159x growth). Test 2 (122x growth)
- Observation of abnormalities (for algal test): In all test concentrations >=1.0 mg/L, the algal cells were abnormally large and malformed. Because of this observation, algae previously exposed to 1000 mg/L were tested for their ability to recover. Their growth was similar to the growth of the control during a 9-day recovery period in test material-free medium, and the algal cells had returned to normal appearance.
- Any stimulation of growth found in any treatment: Not available
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None
- Effect concentrations exceeding solubility of substance in test medium: None

Any other information on results incl. tables

Results of the laboratory studies were compared with enclosure studies conducted with natural phytoplankton assemblages.  Concentrations in the enclosures that first altered community structure were found to be between 27 and 108 mg/L. 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 96-hr EC50 for aquatic algae was 29.0 mg/L based on cell density.
Executive summary:

This study was done to determine the toxicity of the test substance to aquatic algae. Selenastrum capricornutum was exposed to the test substance for 96 -hrs. During this time, the cell density of the algae was measured. The 96 -hr NOEC was 0.5 mg/l. The 96 -hr LOEC was 1 mg/L. The 96 -hr EC50 was 29.0 mg/L based on cell density. Normalized to C11.6 LAS, the value is 0.58 mg/L for the NOEC (method: van de Plassche et al., 1999).