Fatty acids, C10-20-neo-

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to O.E.C.D. Testing Guideline 201 in compliance with the GLPs.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

yes

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, C10-20-neo-

EC Number:

285-549-6

EC Name:

Fatty acids, C10-20-neo-

Cas Number:

85116-96-7

Molecular formula:

C10H20O2 ... C20H40O2

IUPAC Name:

C10-20-neo-Fatty acids

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

No data

Test solutions

Vehicle:

no

Details on test solutions:

water accommodated fraction: loading rated of 10 - 1000 mg/L. Stirred for 69 hours

Test organisms

Test organisms (species):

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

Details on test organisms:

Raphidocelis subcapitata (green algae) was supplied by the Institute of Freshwater Ecology, Windermere (UK) and maintained as a semiaxenic laboratory culture. Three out of each set of four flasks containing WAFs and six controls were inoculated with sufficient R. subcapitata to give an initial concentration of 5000 cells/ml. The flasks were placed in a colled orbital shaker under constant illumination.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

None

Test conditions

Hardness:

No data

Test temperature:

21.0-23.3°C

pH:

8.3

Dissolved oxygen:

No data

Salinity:

Freshwater

Nominal and measured concentrations:

The WAF nominal concentrations (mg/L) were: 0, 10, 30, 100, 300 and 1000.

Details on test conditions:

Algal cultures were exposed in sealed flasks completely filled with 287 ml of test medium including sodium bicarbonate. There were 4 replicate/treatement and 7 for control (test medium + sodium bicarbonate) and 1 blank/concentration. The photoperiod (intensity of irradiation) was continuous (~5000 lux). The test duration was 72 hours with observations made at 0, 24, 48 and 72 hours. Algal cell counts were made with a Coulter Multisizer at observation times of: 0, 24, 48 and 72 hr.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 - < 300 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

growth rate

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 - < 300 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 - < 300 mg/L

Nominal / measured:

nominal

Conc. based on:

other: loading rate

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

Based on the measurment of growth rate, the 72 hr EC50 for algae > 100 mg/L (pH adjusted) under the conditions of the study. The NOEC was estimated to be 100 mg/L (pH adjusted).

Executive summary:

Water Accomodated Fractions (WAF) of VERSATIC 1019 were evaluated in an O.E.C.D. 201 Testing Guideline "Algal Growth Inhibition Test" under static exposure conditions. Based on the measurment of growth rate, the 72 hr EC50 for algae was >100 mg/L (pH adjusted) under the conditions of the study. The NOEC was estimated to be 100 mg/L (pH adjusted).