Bis(C12-C13)alkyl-2-hydroxybutandioate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26.4.1993 - 29.4.1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

According to the OECD-guideline the biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72-hour test period. This corresponds to a specific growth rate of 0.92 day-1. Here the increase is a little bit lower. The number of treatment replicates should be at least six. We have only 3 replicates.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

-Name of test material (as cited in study report): Cosmacol EMI, Butanedioic acid, hydroxy-, di C12-C13-alkyl esters
- Molecular weight (if other than submission substance): 470 - 498
- Substance type: pure active substance
- Physical state: liquid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Selenastrum capricornutum
- Strain: Chlorococalles
- Source (laboratory, culture collection): Institute of Terrestral Ecology Culture Centre of Algae and Protozoa 36 Storey's Way, Cambridge CB3 ODT, England
- Age of inoculum (at test initiation):
- Method of cultivation:

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

Study design

Test type:

static

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

22 - 24 °C

pH:

7.7-7.9

Nominal and measured concentrations:

100 mg/L dispersion concentration; 1 mg/L water solubility

It was not possible, with the analytical technology available to measure the concentration of the substance in the solution.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass flask
- Material, size, headspace, fill volume:
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- Initial cells density: 10000 cells/mL
- Control end cells density: 85000 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 2

GROWTH MEDIUM
- Detailed composition if non-standard medium was used:

OTHER TEST CONDITIONS
- Photoperiod: continuous fluorescent lighting (30 W)

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

not specified

Conc. based on:

other: dispersion concentration (WAF)

Basis for effect:

growth rate

Details on results:

The difference of the biomass of the control and treated groups is less than 25 %. The difference between the average growth figure of the treated group and control group was 0.56 %.

Reported statistics and error estimates:

The percentage difference between the cellular concentration of the group treated and the control group was calculated. The growth curve for both groups was graphically determined and the regression line were calculated. The difference beween the average rate of growth (µ) of treated and control groups was calculated by angular coefficient (b) of regression lines.

Any other information on results incl. tables

time/h	tr. gr. 1/n. cells/mL	tr. Gr. 2/n. cells/mL	tr. Gr.3/n.cells/mL	control 1/n. of cells/mL	control 2/n. cells/mL
0	10000	10000	10000	10000	10000
24	30000	30000	20000	20000	30000
48	60000	50000	50000	50000	60000
72	100000	70000	90000	100000	70000

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Executive summary:

The study was conducted on an algal culture of Selenastrum capricornutum in growth phase, at an initial concentration of 10000 cells/ml.

Algae were exposed to the test material, COSMACOL EMI at a concentration (100 mg/L dispersion concentration) exceeding the water solubility (1 mg/L) for 72 hours.

After 24, 48 and 72 hours cell concentration was measured with a Burker chamber.

Under the experimental conditions, no difference in algal growth was seen between treated and control cultures.