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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:
experimental study
Adequacy of study:
key study
Study period:
15 September to 16 December 2003
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP complinat, guideline, available as an unpublished report, fully acceptable, no restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2004

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
yes
Remarks:
The concentration of the test substance in solution was not determined prior to use. The initial concentration of the test substance was not maintained at 80% in the three lower loading rates throughout the test. Individual treatment solution were prepare
Principles of method if other than guideline:
Contaminant analysis of the water was not performed in a GLP manner but this is not believed to affect the results of the analysis. The equilibrium and range finding tests performed prior to the test were not subject to GLP standards.
GLP compliance:
yes
Remarks:
no certificate

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
heavy pyrolysis fuel oil
Cas numbers included: 68513-69-9, 64741-62-4, 69013-21-4, 8002-05-9
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
NA

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples of each treatment WAF and the control were taken on Day 0 prior to addition of algae and at termination with no headspace. Samples store dunder refrigeration until analysed.
cell density was determined for each test and control chamber using a hemacytometre and microscope at 24, 48, 72 and 96hrs after the beginning of the test.

Test solutions

Vehicle:
no
Details on test solutions:
Equilibrium and range finding test conducted.
Individual treatments prepared by adding the appropriate amount of test substnace to 2.0L of algal nutrient media and sodium bicarbonate. As stirring initiated and after stirring, all treatments appeared colourless/clear with the test substances floating at the surface. WAFs were removed through the outlet at the bottom of the stirring vessel.
No undissolved test substnace was observed in the test chambers during the study. pH was measured on Day 0 and daily after cell density determinations.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Cultured in-house
5 day old stock cultures in log phase growth

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
96 h
Post exposure observation period:
none

Test conditions

Hardness:
not reported
Test temperature:
24.2°C (SD=0.5)
pH:
7.4-7.6 at test initiation and 7.0-8.7 at test termination
Dissolved oxygen:
not reported
Salinity:
NA
Nominal and measured concentrations:
Actual loading rate (mg/l): 0, 0.20, 0.39, 1.1, 2.6, 7.2.
Measured concentrations not reported
Details on test conditions:
algal nutrient medium augmented with sodium bicarbonate
125ml autoclaved glass Erlenmeyer flasks
No headspace. Shaker table (100 rpm)
static - no renewal
Initial cell density: 10000 cells/mL
12 replicates
Light intensity: 8431-8595 lux

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
2.3 mg/L
Nominal / measured:
nominal
Conc. based on:
other: actual loading rate
Basis for effect:
growth rate
Duration:
96 h
Dose descriptor:
EL5
Effect conc.:
2.1 mg/L
Nominal / measured:
nominal
Conc. based on:
other: actual loading rate
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
1.5 mg/L
Nominal / measured:
nominal
Conc. based on:
other: actual loading rate
Basis for effect:
biomass
Duration:
96 h
Dose descriptor:
EL50
Effect conc.:
1.4 mg/L
Nominal / measured:
nominal
Conc. based on:
other: actual loading rate
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
2 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
1.8 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
1.3 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
1.3 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
The EbC50, ErC50 and confidence intervals for inhibition of growth/growth rate slope were determined by a probit regression.
Reported statistics and error estimates:
Calculation of the probit of the growth inhibition /growth rate slope vs the log of the concentration and associated confidence intervals based on the methods of Finney. Calculations were based on the PROC PROBIT procedure of SAS. The NOEC for the EbC50 and ErC50 was based on multiple regression tests and Dunnett. The NOEC was based on estimated values as residual were normally distributed.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The reported 96hr ErC50, based on measured concentrations, was 1.8mg/l.
Executive summary:

The reported 96hr ErC50, based on measured concentrations, was 1.8mg/l. This study is GLP compliant and follows a standard guideline. It is considered reliable and acceptable for use as a key study.