Reaction products of diphenyl ether and 9-methylene nonadecane

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction products of diphenyl ether and 9-methylene nonadecane

EC Number:

943-303-1

Molecular formula:

Variable, substance is a UVCB

IUPAC Name:

Reaction products of diphenyl ether and 9-methylene nonadecane

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L (nominal)
- Sampling method: Samples were taken at 0, 24, 48 and 72 hours after exposure and analysed by GC-MS.

Test solutions

Vehicle:

no

Details on test solutions:

Test solutions were prepared as Water Accommodated Fractions (WAFs) and Water Soluble Fractions (WSFs). Initially amounts of test substance were weighed and added directly to aspirators where they were stirred for 48 hours. The resulting WAF was then filtered using a 5 µm filter paper. The resulting solutions were then used on study. This procedure was confirmed as a result of the range finding phase.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella Subcapitata
- Strain: ATCC22662
- Source (laboratory, culture collection): American Type Culture Collection
- Method of cultivation: Maintained by periodic subculture using Gorham medium. Algae are kept under sterile conditions.

ACCLIMATION
- Acclimation period: 4 days
- Any deformed or abnormal cells observed: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Hardness:

No details

Test temperature:

21.5 to 22.3°C throughout the test

pH:

7.7 to 7.8 throughout the test

Dissolved oxygen:

No details

Nominal and measured concentrations:

Nominal: 100 mg/L (loading rate)
Measured: 1.16 mg/L (TWA)

Details on test conditions:

TEST SYSTEM
- Test vessel: 300 mL Erlenmeyer flask with aluminium cap
- Type: open
- Material, size, headspace, fill volume: 100 mL
- Aeration: No
- Initial cells density: 5 x 10^3
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes (OECD medium as detailed in the respective guideline)

OTHER TEST CONDITIONS
- Sterile test conditions: Yes
- Adjustment of pH: No
- Photoperiod: Continious
- Light intensity and quality: 68 to 74 µE/m2/s

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: cells/mL (biomass) and growth rate

TEST CONCENTRATIONS
- Range finding study: Control, 10 and 100 mg/L
- Test concentrations: Limit test at 100 mg/L
- Results used to determine the conditions for the definitive study: No effects in range finding phase at limit dose.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1.16 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: exceeds limit of aqueous solubility

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.16 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: exceeds limit of aqueous solubility

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): No
- Unusual cell shape: No
- Colour differences: No
- Flocculation: No
- Adherence to test vessels: No
- Aggregation of algal cells: No
- Any stimulation of growth found in any treatment: No
- 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: Yes (no effects observed at limit dose).

Results with reference substance (positive control):

Growth inhibition tests with a reference reagent potassium dichromate are conducted every 6 months. The ErC50 values obtained in the most recent test were within historical ranges for tests conducted at the laboratory.

Reported statistics and error estimates:

The NOEL/NOEC values were determined using a Student's t-test subsequent to a test for homogeneity of variances. No statistical analysis was performed to determine the EC50/EL50 values as no effects were observed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

Validity criteria on test fulfilled

Conclusions:

The effect concentrations to algae exceeded the aqueous solubility of the test substance when performing a limit test at a loading rate of 100 mg/L. The water solubility of the test substance in the aqueous media was determined to be low.