Reaction mass of 2,2'-(ethylenedioxy)diethanol and 3,6,9,12,15-pentaoxaheptadecane-1,17-diol and 3,6,9,12-tetraoxatetradecane-1,14-d

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:

Feb 2, 2015 - Feb 5, 2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study following ISO Guideline No 10253

Justification for type of information:

Read across is based on the category approach. Please refer to attached category document.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

ISO 10253 (Water quality - Marine Algal Growth Inhibition Test with Skeletonema costatum and Phaeodactylum tricornutum)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OSPAR Guidelines for Toxicity Testing of Substances and Preparations Used and Discharged Off-Shore (reference number: 2002-3, amended March 2005)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-(ethylenedioxy)diethanol

EC Number:

203-953-2

EC Name:

2,2'-(ethylenedioxy)diethanol

Cas Number:

112-27-6

Molecular formula:

C6H14O4

IUPAC Name:

2,2'-[ethane-1,2-diylbis(oxy)]diethanol

Test material form:

other: clear colorless liquid

Details on test material:

- Name of test material (as cited in study report): Triethylene glycol
- Physical state: Clear colorless liquid
- Analytical purity: 99.7% per non-GLP certificate of analysis
- Impurities: tetraethylene glycol 0.3%
- Lot/batch No.: D693EBEA03
- Expiration date of the lot/batch: 11 November 2016
- Storage condition of test material: Room temp in the dark

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No additional information

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

No additional information.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A nominal amount of test item (100 mg) was dissolved in culture medium and the volume adjusted to 1 liter to give a 100 mg/l stock solution. An aliquot of this stock solution (850 ml) was inoculated with algal suspension (1.6 ml) to give the required test concentration of 100 mg/l. The stock solution and the prepared concentration were inverted several times to ensure adequate mixing and homogeneity.
- Controls: controls were treated identically but not exposed to the test item; culture medium only
- Evidence of undissolved material (e.g. precipitate, surface film, etc): At the start of the test, all control and test cultures were observed to be clear colorless solutions. After the 72 hr test period, all control and test cultures were observed to be brown colored dispersions.

Test organisms

Test organisms (species):

Skeletonema costatum

Details on test organisms:

- Strain: CCAP 1077/4
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP), Dunstaffnage Marine Laboratory, Oban, Argyll, Scotland

- Culturing media and conditions (same as test or not): Cultures were maintained in the laboratory by the periodic replenishment of culture medium. The culture medium used for the definitive test was the same as that used to maintain the stock culture. The culture was maintained in the laboratory at a temperature of 20 +/- 1 degrees Celsius under continuous illumination (intensity approx. 7000 lux) and constant agitation.

Study design

Test type:

static

Water media type:

saltwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Hardness:

No additional information.

Test temperature:

20 +/- 1 degrees Celsius

pH:

8-8.3

Dissolved oxygen:

No additional information.

Salinity:

No additional information.

Nominal and measured concentrations:

0, 100 mg/l (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass conical flasks
- Type: plugged with polyurethane foam bungs
- Material, size, headspace, fill volume: 250 ml size; containing 100 ml of test preparation
- Initial cells density: 3x1-e3 cells per ml
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural seawater, sterilized by membrane filtration (mean pore diameter 0.2 micron)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: maemocytometer and light microscope

TEST CONCENTRATIONS
- Test concentrations: 0, 100 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

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:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Total Organic Carbon analysis of the 100 mg/l test preparations containing no algal cells at 0 and 72 hours showed equivalent test item concentrations of 102 and 109 mg/l respectively.

The growth rate of Skeletonema costatum was not affected by the presence of TEG over the 72 hour exposure period. Accordingly, the EC50 (0-72 hr) was >100 mg/l. The NOEC was 100 mg/l.

All test and control cultures were inspected microscopically at 72 hours. There were no abnormalities detected in any of the control or test cultures.

Results with reference substance (positive control):

A mean growth rate inhibition of 63% was observed with 1.5 mg/l of 3,5-dichlorophenol.

Reported statistics and error estimates:

Statistical analysis of the growth rate data was carried out for the control and 100 mg/l test group using a Student's t-test incorporating Bartlett's test for homogeneity of variance (sokal and Rohlf 1981). There were no statistically significant differences (p>/=0.5) between the control and 100 mg/l test group.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The growth rate of Skeletonema costatum was not affected by the presence of TEG over the 72 hour exposure period. Accordingly, the EC50 (0-72 hr) was >100 mg/l. The NOEC was 100 mg/l.

Executive summary:

The growth rate of Skeletonema costatum was not affected by the presence of TEG over the 72 hour exposure period. Accordingly, the EC50 (0-72 hr) was >100 mg/l. The NOEC was 100 mg/l.