1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Apr - 03 May 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

459-520-5

EC Name:

-

Cas Number:

132182-92-4

Molecular formula:

Hill formula: C7H3F13O CAS formula: C7H3F13O

IUPAC Name:

1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: PDC Lot 1, Pail 2
- Expiration date of the lot/batch: 23 Mar 2006
- Purity: 99.959%
- Synonyms: MTDID 665

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

Test substance was quantitatively added directly to test vessels. Optimal contact between substance and medium was ensured by applying continuous aeration and stirring.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: Sludge was collected from municipal sewage treatment plant: 'Waterschap de Maaskant', 's-Hertogenbosch, the Netherlands.The sludge was coarsely sieved, washed and diluted with tap water. A small amount of the sludge was weighed and dried at ca. 105°C to determine the amount of suspended solids (3.3 or 3.4 g/L of sludge, as used for the specific test). The sludge was collected one day before use. Before use the pH was checked (measured value: 8.0 or 7.9).

- Method of cultivation: Because the sludge was used one day after collection, 50 mL of synthetic sewage feed* was added to each litre of activated sludge at the end of the collection day. The sludge was kept aerated at test temperature until use (*synthetic sewage feed: 16 g peptone, 11 g meat extract, 3 g urea, 0.7 g NaCI, 0.4 g CaCI2·2(H2O), 0.2 g MgSO4·7(H2O), 2.8 g K2HPO4 dissolved in 1 L RO water and filtered, final pH 7.4).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

18.6 - 20.4 °C

pH:

8.1 - 8.4

Dissolved oxygen:

Continuous aeration throughout exposure period. Range of measured dissolved oxygen [DO] values at start of observation period were 6.8 - 8.7 mg/L

Nominal and measured concentrations:

Nominal concentrations 100 mg/L, 180 mg/L, 320 mg/L, 560 mg/L, or 1000 mg/L during 3-hour test. 30-min test done separately as limit test at 1000 mg/L. No analytical monitoring.

Details on test conditions:

TEST SYSTEM
- Test vessel: All glass bottles/vessels.
- Type (delete if not applicable): Open during exposure. Closed during observation.
- Material, size, headspace, fill volume: Test substance and 16 mL synthetic sewage were made up to 300 mL in RO water, and 200 mL sludge suspension was added to bring total volume to 500 mL in a 1-L bottle. Test solutions were transferred to a 300-mL bottle for oxygen measurements
- Aeration: Continuous aeration with pipette, and stirring.
- Nitrification assessed: no
- No. of vessels per concentration (replicates): One each for 3-hour test, two for 30-min limit test, one each for reference substance 3,5-dichlorophenol.
- No. of vessels per control (replicates): Three blanks.
- Biomass loading rate: 1.3 g/L suspended solids in the final test mixture.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges.
- Intervals of water quality measurement: Not specified. Water quality data not provided.

OTHER TEST CONDITIONS
- Adjustment of pH: none.
- Light intensity: not specified.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Dissolved oxygen concentration. Measuring equipment: WTW Inolab Oxi Level 2 supplied with a WTW CellOx 325 oxygen electrode, electrolyte type ELY/G.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 2

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test substance was not completely soluble in test medium at the loading rates initially prepared.

Results with reference substance (positive control):

- Results with reference substance valid?: Yes (see Tables 1, 2)
- Relevant EC50 values:
3 hour test, 12.1 mg/L
30 min test, 13.1 mg/L

Any other information on results incl. tables

Table 1, Results from the 3-hour test

Sample	Conc. or loading rate (mg/L)	Initial oxygen conc (mg O2/L)	Respiration rate mg O2/(L∙h)	% Inhibition relative to control mean
Blank controls
C1	0	7.3	39.7	─
C2	0	7.9	35.3	─
C3	0	6.8	41.0	─
Mean (CV)			38.7 (7.72%)
Reference sub.
R1	1.0	7.5	35.3	6
R2	3.2	7.8	30.0	20
R3	10	8.2	21.6	42
R4	32	8.7	10.1	73
Test sub.
T1	100	7.8	34.5	10
T2	180	8.1	34.2	10
T3	320	7.8	35.6	7
T4	560	7.8	36.1	5
T5	1000	7.4	37.6	1

Table 2, Results from the 30-min test

Sample	Conc. or loading rate (mg/L)	Initial oxygen conc (mg O2/L)	Respiration rate mg O2/(L∙h)	% Inhibition relative to control mean
Blank controls
C1	0	7.7	41.8	─
C2	0	8.0	42.2	─
C3	0	7.8	43.3	─
Reference sub.
R1	3.2	7.7	36.0	14
R2	10	8.1	23.5	44
R3	32	8.4	11.8	72
Test sub.
T1	1000	7.5	42.9	0
T2	1000	6.8	44.8	(-5)¹

1, stimulation of respiration v. controls. Result not considered significant.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

respiration > 20 mg O2/(L∙h) [38.7 mg O2/(L∙h)], CV <30% [7.72%]. EC50 for 3,5-DCP 2-25 mg/L (13.1 mg/L)

Conclusions:

HFE s-601 is not inhibitory to activated sludge respiration (3-h EC50 >1000 mg/L) (OECD TG209)

Executive summary:

The toxicity of HFE s-601 to activated sludge organisms was assessed in an assay performed according to OECD TG209.  The test solution was made by direct addition to test solutions.  No inhibition was observed at the highest concentration tested after 30 minute and three hour exposures.  The 30-min and 3-hour EC50s to sludge are >1000 mg/L.

The study was conducted in accord with GLP criteria and test method OECD209. It is classified as reliable without restrictions and is suitable for Risk Assessment, Classification & Labelling, and PBT Analysis.