Poly(oxy-1,2-ethanediyl), α-(carboxymethyl)-ω-hydroxy-, C16-18 (even numbered) and C18-unsatd. alkyl ethers

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998-01-28 to 1998-02-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

(adopted April 4th 1984)

Deviations:

yes

Remarks:

In the guideline a dry sludge concentration of the activated sludge of 4 g/L ± 10% is given. For the activated sludge of Hildesheim a lower dry sludge concentration of 3 g/L ± 20% is sufficient.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture:
- Name and location of sewage treatment plant where inoculum was collected: Municipal sewage treatment plant of D-31137 Hildesheim
- Pretreatment: The sludge was washed twiee with autoclaved tap water and diluted 1:3
- Nutrient solution Synthetic waste water according to OECD 209
- Initial biomass concentration: 2.8 g/L dry sludge concentration

Test type:

static

Water media type:

other: Synthetic waste water according to OECD 209

Limit test:

no

Total exposure duration:

3 h

Test temperature:

18 - 22 °C

pH:

7.38

Nominal and measured concentrations:

Nominal concentrations of test substance: 32 - 100 - 320 - 1000 - 3200 - 10000 mg/L
Nominal concentrations of the reference substance: 58 - 100 - 180 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 1000 mL Erlenmeyer flasks, DIN 12440
- Material, size, headspace, fill volume: 1 liter volume glass flasks. Fill volume of 500 mL
- Aeration: permanent ventilation
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2
- No. of vessels per abiotic control (replicates):
- Sludge concentration (weight of dry solids per volume): 2.8 g/L
- Nutrients provided for bacteria: Synthetic waste water according to OECD 209


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 200 mL inoculum + 16 mL synthetic waste water + 284 mL aqua demin. + directly weighing of the test substance concentrations

OTHER TEST CONDITIONS
- Adjustment of pH: no


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : oxygen depletion of the centrot. reference and test substance were measured after 3 h incubation by means of oximeter and recorded for at least 3 minutes on a flat bed recorder.

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 10 - 100 - 1000 mg/L.
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

Copper (II) sulphate pentahydrate

Duration:

3 h

Dose descriptor:

other: EC 20

Effect conc.:

128 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

429 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95% CL = 351 - 523 mg/L

Duration:

3 h

Dose descriptor:

other: EC 80

Effect conc.:

1 437 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

All tested concentration levels were dissolved homogeneously.
The test substance concentration levels of 320, 1000 and 3200 mg/L were foaming.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: The EC50 of the reference substance copper(II)-sulphate-pentahydrate is in the confidence range of 60 - 138 mg/L (result: 125 mg/L).

Reported statistics and error estimates:

Probit analysis

Inhibition (%) of the respiration rate by the test item

Test Concentration
10000 mg/L	3200 mg/L	1000 mg/L	320 mg/L	100 mg/L	32 mg/L
97%	92%	71%	44%	15%	7%

 

Validity criteria fulfilled:

yes

Conclusions:

In this Activated sludge respiration inhibition test the 3 h EC50 of Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid was 429 mg/L (95% c.i. 351 - 523 mg/L).

Executive summary:

In a 3 h respiration inhibition study, activated sludge a predominantly municipal sewage treatment plant was exposed to Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid at nominal concentrations of 0 (control), 32, 100, 320, 1000, 3200 and 10000 mg/L in accordance with OECD Guideline 209 (1984). Copper (II) sulphate pentahydrate at concentrations of 58, 100 and 180 mg/L was used as reference substance. The respiration rates of the control, reference and test item were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the control respiration rates. The inhibition of respiration for the test item ranged from 7% to 97%.

The 3 h EC50 of Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid was 429 mg/L (95% c.i. 351 - 523 mg/L).

Description of key information

3 h EC50 = 429 mg/L (95% c.i. 351 - 523 mg/L) (RL1, GLP, OECD TG 209)

Key value for chemical safety assessment

EC50 for microorganisms:

429 mg/L

Additional information

In a 3 h respiration inhibition study, activated sludge a predominantly municipal sewage treatment plant was exposed to Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid at nominal concentrations of 0 (control), 32, 100, 320, 1000, 3200 and 10000 mg/L in accordance with OECD Guideline 209 (1984). Copper (II) sulphate pentahydrate at concentrations of 58, 100 and 180 mg/L was used as reference substance. The respiration rates of the control, reference and test item were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the control respiration rates. The inhibition of respiration for the test item ranged from 7% to 97%.

The 3 h EC50 of Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid was 429 mg/L (95% c.i. 351 - 523 mg/L).