3,6,9-trioxaundecane-1,11-diol

Sediment toxicity

Administrative data

Endpoint:

sediment toxicity: short-term

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

March 9, 1993 - March 16, 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study following PARCOM Ring test protocol for the Abra Test

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:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: PARCOM Ring test protocol for the Abra Test, November 1990, including the alterations in the Standard Procedures produced by Dr. T. Stromgren, September 1992.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-oxydiethanol

EC Number:

203-872-2

EC Name:

2,2'-oxydiethanol

Cas Number:

111-46-6

IUPAC Name:

2,2'-oxydiethanol

Test material form:

other: colourless liquid

Details on test material:

- Name of test material (as cited in study report): Diethylene glycol
- Physical state: Colourless liquid
- Analytical purity: Min 98.8%
- Lot/batch No.: TG/DEG-E/691
- Stability under test conditions: Water: Yes
- Storage condition of test material: At room temperature in the dark

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable.

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

No additional information.

Test substrate

Vehicle:

no

Details on sediment and application:

Test medium: 250 ml sediment suspension with a salinity of 33 o/oo S
Sediment: Collected from a locality where also A. alba can be found and sieved through a 45 micron mesh. Storage at 6-8 degrees Celsius
Preparation of test medium: Prepared using a 1/10 stock solution by dispersing 1000 mg of test substance in 9 g distilled water (ca. 20 degrees Celsius). The dispersion was apparently homogenous. Exact aliquots of this stock solution were added to batches of 500 ml standard sediment suspension (5% sediment particle content (dry-weight) and particle size of < 45 micron) providing the required test concentrations.

Test organisms

Test organisms (species):

other: Abra alba

Details on test organisms:

TEST ORGANISM
- Common name: White furrow shell
- Justification for species other than prescribed by test guideline: This organism has been selected as a sediment reworker sensitive to toxic substances in the marine environment. It was one of the species tested in the PARCOM Ring test.
- Diameter: > 5 mm

ACCLIMATION
- Acclimation period: at least 5 days before the start of the pre-exposure period.
- Acclimation conditions (same as test or not): In natural sediment under continous flow of natural seawater at ambient temperature and salinity of > 20 o/oo.
- Type of food: homogenized faeces of Mytilus

Study design

Study type:

laboratory study

Test type:

not specified

Water media type:

saltwater

Type of sediment:

natural sediment

Limit test:

no

Exposure duration

Duration:

5 d

Exposure phase:

total exposure duration

Post exposure observation period:

No additional information.

Test conditions

Hardness:

No data

Test temperature:

10.7-11.3 degrees Celsius

pH:

7.6-7.7

Dissolved oxygen:

> 70% of air saturation value

Salinity:

No data

Ammonia:

No data

Nominal and measured concentrations:

0, 50, 100, 200, 300, 500 mg/l (nominal)

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Polyethylene tubes with inner diameter of 36 mm, outer diamter of 40 mm and mesh size of 90 micron. Series of 15 tubes are glued together in a rack of 3x5 sieves, corresponding to about 12x 20 cm
- Aeration frequency and intensity: Oxygen concentration was checked on the 2nd and 4th day of exposure. Should the oxygen saturation be below 70% the sieve racks were lifted out of the medium for a short period (about 20 seconds) and the medium stirred to ensure sufficient oxygenation.


EXPOSURE REGIME
- No. of organisms per container: 1 test organism/tube; about 15 individuals per container in 250 ml of 5% standard sediment suspension
- No. of organisms per treatment group: 25-29 per group during pre-exposure and 25-27 per group during the exposure period
- No. of organisms per control / vehicle control: 57 during pre-exposure and 51 during exposure
- No. of replicates: Two containers were used for each concentration

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Fecal pellet production measured 2 days before the exposure and during the last 24 hours of exposure; measured as dry weight (flushed with fresh water before drying to remove salt)

VEHICLE CONTROL PERFORMED: yes: medium without test substance or other additives

TEST CONCENTRATIONS
- Test concentrations: 50, 100, 200, 300, 500 mg/l

Reference substance (positive control):

yes

Remarks:

2.4 mg/l of 3,5-dichlorophenol (97%)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

5 d

Dose descriptor:

EC50

Effect conc.:

331 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fecal pellet production

Remarks on result:

other: 95% CI: 295-367

Effect concentrations 2

Duration:

5 d

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: fecal pellet production

Details on results:

Table 1 shows the data for fecal pellet production at the different concentrations during both pre-exposure and the exposure period.
The test organisms in the control series behaved normally producing 3.92 mg/day per individual (ind.) during the exposure period versus 3.83 mg/ind./day during the pre-exposure period.
Normalized fecal pellet production in percentage of control decreased with increasing concentration resulting in 60% reduction at 500 mg/l (nominal). No significant reduction of fecal pellet production was recorded at the test concentration of 100 mg/l (15%).

Results with reference substance (positive control):

The sensitivity control showed a defecation rate of 43% relative to the control which is within the acceptable range for the reference substance (i.e. a fecal production rate of 25-45% of the control after 5 days of exposure).

Reported statistics and error estimates:

Calculation of the EC50 for reduction of fecal pellet production was based on the non-linear model: Y = -30.0logX + 131 with R2 = 0.91.
The EC50 for 5 days of exposure was calculated to be nominally 331 mg/l with a standard error of +/- 18 mg/l (corresponding to a 95% confidence interval ranging from 295 to 367 mg/l).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 for 5 days of exposure to DEG was calculated to be nominally 331 mg/l with a standard error of +/- 18 mg/l (corresponding to a 95% confidence interval ranging from 295 to 367 mg/l). The NOEC was 100 mg/l.

Executive summary:

The EC50 for fecal pellet production of Abra alba after 5 days of exposure to DEG was calculated to be nominally 331 mg/l with a standard error of +/- 18 mg/l (corresponding to a 95% confidence interval ranging from 295 to 367 mg/l). The NOEC was 100 mg/l.