Fatty acids, vegetable-oil, Me esters, sulfurized

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

FROM 13 OCT 2017 TO 11 JUL 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

yes

Remarks:

The measurement period was partly less than 5 min. and the oxygen conc. still above 2 mg/L. Linearity of all regression curves was given and the correlation of the inhibition values within the test replicates was good, this was stated as uncritical.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Fatty acids, vegetable-oil, Me esters, sulfurized

EC Number:

276-337-4

EC Name:

Fatty acids, vegetable-oil, Me esters, sulfurized

Cas Number:

72102-30-8

IUPAC Name:

Fatty Acids, vegetable-oil, Me-Esters, sulfurized

Test material form:

liquid

Details on test material:

- Density: 0.95 g/mL
- Batch no.: 71012767

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

Nominal concentration 1000 mg/L

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant in D-67435 NW-Lachen-Speyerdorf.
- Preparation of inoculum for exposure: Upon arrival in the test facility, the sludge was filtrated, washed with tap water 3 times and re-suspended in tap water. The activated sludge was aerated until usage in the test and fed daily with 50 mL synthetic sewage feed /L.
- Pretreatment: On the day before the experiment, the inoculum was taken from its source, washed, aerated and the dry matter was determined. Volume was adapted to the desired content of dry matter. The nutrient solution was thawed and the sludge was fed with 50 mL nutrient solution / L sludge. On the day of the experiment, the dry matter was determined once more.
- Initial biomass concentration: not stated

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Test conditions

Hardness:

0.71 mmol/L

Test temperature:

20.0 – 21.3 °C

pH:

8.26

Dissolved oxygen:

not stated

Conductivity:

at 25 °C 174 μS/cm

Nominal and measured concentrations:

Nominal concentration 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers were used as test vessels. They were cleaned before use following SOP 114 003 01 in the current edition.
- Type: open
- Material, size, headspace, fill volume: Glass, 800 – 1000 mL
- Aeration: yes
- No. of vessels per concentration (replicates):
1 replicate/treatment (positive control and test item lower concentrations)
5 replicates for test item treatment 1000 mg/L
- No. of vessels per control (replicates): 2 replicates before and 2 after measuring positive control and test item, respectively
- Sludge concentration (weight of dry solids per volume): 1.39 g suspended solids/L
- Nutrients provided for bacteria:
Feeding: nutrient solution, 16 mL/vessel
Composition of nutrient solution (synthetic sewage):
Peptone 16.0 g
Meat Extract 11.0 g
Urea 3.0 g
NaCl 0.7 g
CaCl2*2H2O 0.4 g
MgSO4*7H2O 0.2 g
K2HPO4 2.8 g
Deionised water ad 1000 mL
The pH of the solution was 7.0 and therefore within the range of 7.5 ± 0.5.

- Biomass loading rate: not stated

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Wasserwerk Maikammer
- Particulate matter: not stated

OTHER TEST CONDITIONS
- Adjustment of pH: no

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (CAS-No. 591-35-5)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 2

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Effect concentrations 3

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

Details on results:

- Any observations that might cause a difference between measured and nominal values: not reported
- Effect concentrations exceeding solubility of substance in test medium: yes
- Adsorption: not reportet
- Blank controls oxygen uptake rate: Mean O2 consumption: 28.57 mg/(L*h)
- Coefficient of variation of oxygen uptake rate in control replicates: 5.73

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: 3h-EC50 8,1 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item was tested using 4 concentrations ranging from 1000 to 1 mg/L nominal concentration. For the treatment 1000 mg/L, 5 replicates were used; for the other treatments, 1 replicate each.
Because no significant inhibition was observed, no additional experiment had to be performed.
All validity criteria were met. For the estimation of the EC50 of the positive control, the fits showed good statistical correspondence of the data with the dose-response-equation. The positive control gave an EC50 of 8.1 mg/L (95 % confidence interval 6.4 – 9.7 mg/L) which lie within the recommended range of 2 – 25 mg/L. The coefficient of variation of oxygen uptake rate in control replicates was below 30% at the end of the test. The oxygen uptake rate of the blank controls was above 20 mg O2 per gram activated sludge in 1 hour.
No observations were made which might cause doubts concerning the validity of the study
outcome.
The result of the test can be considered valid.