Bis[2-[2-(1-methylethyl)-3-oxazolidinyl]ethyl] hexan-1,2-diylbiscarbamate

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:

1998-06-30 to 1988-07-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

(ISO 8192-1986)

Deviations:

no

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

No analytical monitoring

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance has been solved in water.
- Eluate: Water
- Controls: Water

Test organisms (species):

activated sludge

Details on inoculum:

- Laboratory culture: Yes
- Source: 3L LABORANLAGE (OECD)
- Initial biomass concentration: 6.0g dry substance/L
- Synthetic sewage feed solution:
The medium should be prepared to contain the following constituents at the stated amounts:
- Peptone: 16 g
- Meat extract (or a comparable vegetable extract): 11 g
- Urea: 3 g
- Sodium chloride (NaCl): 0.7 g
- Calcium chloride dihydrate (CaC12, 2H2O): 0.4 g
- Magnesium sulphate heptahydrate (MgSO4, 7H2O): 0.2 g
- Anhydrous potassium monohdydrogen phosphate (K2HPO4): 2. 8g distilled or deionized water to 1 litre

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

21.4 - 23.6 °C

pH:

7.7 - 7.8

Dissolved oxygen:

4.0 - 8.9 mg/L O2 (1-10 min)

Details on test conditions:

TEST SYSTEM
- Material, size, headspace, fill volume: Total volume 250 mL
- No. of vessels per concentration (replicates): 1
- No. of vessels per control: 1
- No. of vessels per vehicle control: 2 (different concentrations)

OTHER TEST CONDITIONS
- Adjustment of pH: Not needed

TEST CONCENTRATIONS
- Range finding study concentration: 100, 1000, 10000 mg/L
- Main study concentration: 1000, 1800, 3200, 5600, 10000 mg/L
- Reference substance concentration: 1 mg/L, 20 mg/L
- Autoxidation (without activated sludge) concentration: 10000 mg/L

Other:
Becasue of the insolubility of the test item in water the test item sedimented at the pH electrode. The concentration in the test vessels may not correspond with the nominal concentration.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

894 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

3 534 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Key result

Duration:

3 h

Dose descriptor:

other: EC95

Effect conc.:

20 630 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

Pre-test:
Inhibition [%] / respiration rate [mg/L*h] test substance
100 mg/L: 0 % / 19 mg/L*h
1000 mg/L: 8.3 % / 17 mg/L*h
10000 mg/L: 66.7 % / 6 mg/L*h

Inhibition [%] / respiration rate [mg/L*h] reference substance
1 mg/L: 9.5 % / 16 mg/L*h
20 mg/L: 66.7 % / 67 mg/L*h

Main test:
Inhibition [%] / respiration rate [mg/L*h] test substance
1000 mg/L: 0 % / 16 mg/L*h
1800 mg/L: 33.3 % / 10 mg/L*h
3200 mg/L: 60 % / 6 mg/L*h
5600 mg/L: 60 % / 6 mg/L*h
10000 mg/L: 80 % / 3 mg/L*h

Control (without test substance)
Respiration rate [mg/L*h]: 15
Inhibition [%]: 0

Autoxidation (without activated sludge but with test substance)
Respiration rate [mg/L*h]: 0
Inhibition [%]: 0

Results with reference substance (positive control):

Inhibition [%] / respiration rate [mg/L*h] reference substance
1 mg/L: 8.6 % / 14 mg/L*h
20 mg/L: 60 % / 6 mg/L*h

Reported statistics and error estimates:

The EC50 was calculated with a graphic evaluation (Probit Analysis).

Validity criteria fulfilled:

yes

Remarks:

Validity of the test was examined due to the graphic evaluation of the reference substance

Conclusions:

The activated sludge respiration inhibition test has been conducted with Incozol 4. The study resulted in an EC50 of 3534 mg/L and an EC10 of 894 mg/L.

Executive summary:

The test was conducted according the the test guideline OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test) (ISO 8192-1986). The activated sludge taken from a laboratory culture was fed with a synthetic sewage solution. The test item was exposed to the activated sludge for 3 hours.

First a range test with the test item concentrations of 100, 1000, 10000 mg/L was conducted. The range test resulted in a 8.3 % inhibition and a respiration rate of 17 mg/L*h at the concentration of 1000 mg/L. Therefore, the main test concentrations were set as follows: 1000, 1800, 3200, 5600, 10000 mg/L. The maximum test concentration was chosen based on the solubility of the test substance. Additionally, a control (water) was measured at the start and at the end of the exposure time and a reference substance (3,5-Dichlorophenol) with two different concentrations was also included. During the exposure time the oxygen concentration, growth inhibition, pH and temperature was measured.

The EC values were calculated with a graphic evaluation (Probit Analysis). The test resulted in an EC50 of 3534 mg/L and an EC10 of 894 mg/L for the test item Incozol 4.

Description of key information

An activated sludge respiration inhibition test has been conducted with Incozol 4. The study resulted in an EC50 of 3534 mg/L and an EC10 of 894 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

3 534 mg/L

EC10 or NOEC for microorganisms:

894 mg/L

Additional information

The test was conducted according the the test guideline OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test) (ISO 8192-1986). The activated sludge taken from a laboratory culture was fed with a synthetic sewage solution. The test item was exposed to the activated sludge for 3 hours. First a range test with the test item concentrations of 100, 1000, 10000 mg/L was conducted. The range test resulted in a 8.3 % inhibition and a respiration rate of 17 mg/L*h at the concentration of 1000 mg/L. Therefore, the main test concentrations were set as follows: 1000, 1800, 3200, 5600, 10000 mg/L. The maximum test concentration was chosen based on the solubility of the test substance. Additionally, a control (water) was measured at the start and at the end of the exposure time and a reference substance (3,5-Dichlorophenol) with two different concentrations was also included. During the exposure time the oxygen concentration, growth inhibition, pH and temperature was measured. The EC values were calculated with a graphic evaluation (Probit Analysis). The test resulted in an EC50 of 3534 mg/L and an EC10 of 894 mg/L for the test item Incozol 4.