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Toxicity to microorganisms

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Endpoint:
activated sludge respiration inhibition testing
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Please refer to the category approach justification provided in section 13.
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
140 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks on result:
other: Source, key, 9002-92-0, Sasol, 1997, BH-97/04, activated sludge
Duration:
16.9 h
Dose descriptor:
EC50
Effect conc.:
> 10 g/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth inhibition
Remarks on result:
other: Source, supporting, 68439-50-9, Sasol, 1996, PZ-96/06, P. putida
Duration:
5 h
Dose descriptor:
EC50
Effect conc.:
> 2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Remarks on result:
other: Source, supporting, 68439-50-9, Sasol, 1996, SK-93/17, P. putida
Executive summary:

The toxicity to microorganisms is assessed on the basis of data from three studies with similar alcohol ethoxylates (C12, 4 EO, CAS 9002-92-0, C12 -14, 2 EO, CAS 68439 -50 -9 and C12-14, 6 EO, CAS 68439-50-9).

In a respiration test with domestic activated sludge according to EG-guideline 88/302/EG and GLP (Diefenbach, 1997), an EC50 (3h) of 140 mg/L was determined. This finding is supported by the results of a two tests with Pseudomonas putida that revealed an EC50 (16.9 hours) > 10 g/L and an EC50 (5 h) > 2 mg/l.

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
14 March 1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to guideline
Guideline:
other: EG Guideline 88/302/EG
Version / remarks:
30.05.1988
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
Trade name: Marlowet BL
Analytical monitoring:
no
Vehicle:
yes
Details on test solutions:
All test vessels were supplemented with 200 µl Baysilone as defoaming agent and vigorously stirred prior to the amendment of sludge.
Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
Approximately 5 L activated sludge were taken from the municipal sewage treatment plant Marl-West, Germany, on the day before test start. The sludge was sedimented and washed with 1.5 L tap water and aerated for 10 min after additional sendimentation. The sludge was then suspended in 4 L of tap water and 200 mL synthetic sewage and was aerated and stirred. On the day of the test, the sludge material was washed twice and resuspended in 3 L tap water and had a dry weight of 3.82 g/L.
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Hardness:
No details given
Test temperature:
20 ± 2 °C
pH:
test end: 8.1 - 8.2 in test substance and controls, 8.4 - 8.5 in reference controls
Dissolved oxygen:
test end at start of O2 measurement: 6.14 - 8.56 mg/L
Nominal and measured concentrations:
Nominal: 25, 50, 100, 150, 200 mg/L
Details on test conditions:
The test solutions in the vessels were continously stirred and aerated with clean, oil-free air (flow rate 0.5 - 1 L/min) to maintain a minimal concentration of 2.5 mg/L dissolved oxygen. All vessels contained 16 mL synthetic sewage and 200 mL inoculum and were filled to 500 mL with tap water after amendment of the emulsified test substance.
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Respiration rate after 3 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2x

Reference substance (positive control):
yes
Remarks:
3,5-Dichlorophenol
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
140 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
- Controls: The difference between the two controls without test substance was 1.1%
- At the time of measurement the O2 consumption curve exhibited linearity
Results with reference substance (positive control):
- Results with reference substance valid: yes
- Relevant effect levels: EC50 = 6.7 mg/L
Conclusions:
An EC50 of 140 mg/l was found out for the inhibition of respiration of activated sludge.
Executive summary:

In a respiration test with domestic activated sludge according to EG-guideline 88/302/EG and GLP, an EC50 (3 h) of 140 mg/L was determined.

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
13 - 14 NOV 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to guideline
Guideline:
DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)
GLP compliance:
yes
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
Pseudomonas putida
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
16.9 h
Test temperature:
21.1 - 21.2 °C
Nominal and measured concentrations:
nominal: 0.1, 1, 10, 100, 1000 and 10000 mg a.s./L
Details on test conditions:
TEST SYSTEM
- Test vessel: sterile 250 mL Erlenmeyer flasks
- Type (delete if not applicable): closed with cellulose stoppers
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6 growth controls, 1 pH-control, 1 blank
Reference substance (positive control):
no
Key result
Duration:
16.9 h
Dose descriptor:
EC10
Effect conc.:
> 10 g/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth inhibition
Key result
Duration:
16.9 h
Dose descriptor:
EC50
Effect conc.:
> 10 g/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
growth inhibition

Concentration
[mg a.s./L]

Inhibition of cell growth (%)

0.1

-0.1

1

-0.3

10

-1.8

100

-0.7

1000

-4.6

10000

-7.4

Validity criteria fulfilled:
yes
Endpoint:
toxicity to microorganisms, other
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
Test 1: 19 - 20 OCT 1993; Test 2: 21 - 22 OCT 1993
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
no guideline followed
Principles of method if other than guideline:
Oxygen consumption test according to a method developed by Hüls AG
GLP compliance:
yes
Specific details on test material used for the study:
Trade name: Marlipal 24/20
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
Pseudomonas putida
Details on inoculum:
- Laboratory culture: in-house culture originally obtained from "Institut für Wasser-, Boden- und Lufthygiene des BGA (Berlin)"
- Preparation of inoculum for exposure: 200 mL steril medium was inoculated with 80 mL bacteria suspension (liquid culture of test organism, approximately 19 h incubation time, bacterial count approximately 10 x 10 exp. 5 bacteria/mL - extinction 436 nm: 0.29 - 0.31). Inoculum was aerated and stirred for 5 min.
- Initial biomass concentration: bacterial count approximately 10 x 10 exp. 5 bacteria/mL
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
5.33 h
Remarks on exposure duration:
1st test: 5.33 h; 2nd test: 5.5 h
Test temperature:
pre-culture:
Test 1: 24.8 - 25.0 °C
Test 2: 24.9 - 25.0 °C

incubation period:
test 1: 24.7 - 26.6 °C
test 2: 24.7 - 26.0 °C
Nominal and measured concentrations:
nominal: 100, 500, 1000 and 2000 µg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 100 mL BSB-bottles
- No. of organisms per vessel: 10 x 10 exp. 5 bacterial count
- No. of vessels per concentration (replicates): 4 (in two of them 1 mL HgCl3 was added for determination of the degree of autoxidation)
- No. of vessels per control (replicates): 5


Reference substance (positive control):
no
Duration:
5 h
Dose descriptor:
EC50
Effect conc.:
> 2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

No dose-response relationship of the test results, thus no EC10 available

Test

Concentration [µg/L]

100

500

1000

2000

1

11.1%

7.3%

5.5%

2.6%

2

11.0%

9.6%

5.1%

4.5%

Description of key information

EC50 (3h) = 140 mg/L for activated sludge

EC50 (16.9h) > 10 g for Pseudomonas putida

Key value for chemical safety assessment

EC50 for microorganisms:
140 mg/L

Additional information

Since no data for decan-1-ol, ethoxylated, 1-2.5EO (CAS 26183-52-8) are available, toxicity to microorganisms is assessed on the basis of data from three studies with similar alcohol ethoxylates (C12, 4 EO; CAS 9002-92-0, C12 -14, 2 EO; CAS 68439-50-9 and C12-14, 6 EO; CAS 68439-50-9).

In a respiration test with domestic activated sludge according to EG-guideline 88/302/EG and GLP (Sasol, 1997), an EC50 (3h) of 140 mg/L was determined. This finding is supported by the results of a two tests with Pseudomonas putida that revealed an EC50 (16.9 hours) > 10 g/L and an EC50 (5 h) > 2 mg/L (Sasol, 1996 & Sasol, 1993).