Fatty acids, palm-oil, hydrogenated

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

From Mar. 10, 2010 to Apr. 28, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to standard guidelines in compliance with GLP.

Justification for data waiving:

other:

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.6800 (Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Oils, vegetable, deodorizer distillates

EC Number:

270-700-0

EC Name:

Oils, vegetable, deodorizer distillates

Cas Number:

68476-80-2

IUPAC Name:

68476-80-2

Constituent 2

Reference substance name:

Glycerides, C16-18 and C18-unsatd., deodorizer distillates

EC Number:

272-911-3

EC Name:

Glycerides, C16-18 and C18-unsatd., deodorizer distillates

Cas Number:

68920-03-6

IUPAC Name:

Glycerides, C16-18 and C18-unsatd., deodorizer distillates

Details on test material:

- Name of test material (as cited in study report): Oil, vegetable, deodorizer distillates
- Substance type: Glycerides, fatty acids and unsaponifiable matter of vegetable origin
- Physical state: Liquid/dark brown
- Purity test date: Jan. 14, 2010
- Expiration date of the lot/batch: July 14, 2010
- Storage condition of test material: In original container, at room temperature (15 - 25°C), in the dark
- Other:
- Solubility: Insoluble in water

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

Not applicable

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances):
The test material was directly dosed into test flask and tap water was added. For complete emulsification of test material, this mixture was stirred for about 24 h at 21°C in the dark/diffuse light before adding the inoculum.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source: Municipal sewage treatment plant, Dermstadt, Germany. This STP predominantly receives domestic waste.

- Preparation of inoculum for exposure: The sludge was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was resuspended in tap water and again centrifuged. The latter procedure was repeated three times. The washed sludge was resuspended in tap water and 50 mL synthetic sewage feed/L was added. The sludge was kept at room temperature under continuous aeration until use overnight. The suspension was fed on the first day before starting the experiment. The dry wt of the activated sludge was determined, and diluted to 3.8 g/L with tap water immediately before use. The pH of the activated sludge was 7.6.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

None

Test conditions

Hardness:

Not reported

Test temperature:

22°C during dissolution phase (24 h)
19 °C during pre-incubation (3 h)
17-19 °C during evaluation period

pH:

At start of exposure (0 h): 7.5-8
At end of exposure (3 h): 8.4-8.6

Dissolved oxygen:

At start of exposure (0 h): 7.9-8.2 mg O2/L
At end of exposure (3 h): 8.2-8.7

Salinity:

Not reported

Nominal and measured concentrations:

Nominal concentration: 0, 10, 32, 100, 320, and 1000 mg/L

Details on test conditions:

- Test vessel: Glass flasks and karlsruher flasks
- Type (delete if not applicable): Closed
- Material, size, headspace, fill volume: Glass flasks of 1 L volume and Karlsruher flasks of 250 mL volume
- Aeration: Compressed air (0.8L/min)
- No. of vessels per concentration (replicates): One
- No. of vessels per control (replicates): Two (Control received tap water, synthetic sewage and inoculum without addition of the test material)


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water
- Synthetic sewage composition:
16 g Peptone
11 g Meat extract
3 g Urea
0.7 g NaCI
0.4 g CaCl2.2H2O
0.2 g MgSO4.7H2O
2.8 g K2HPO4
filled up to 1 L with deionised water


OTHER TEST CONDITIONS: The pH and the oxygen concentrations were determined at the start and at the end of the incubation period in all treatments. The water temperature was measured in one control medium at the start and the end of the incubation period.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Well-mixed sample of each test medium was poured into Karlsruher flask after 3 h of incubation time for the measurement of the respiratory rate. The oxygen concentration was measured with an oxygen electrode and was recorded for about 10 min. During the measurement, the samples were continuously stirred. The oxygen consumption was determined from the most linear part of the respiration curve.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Range finding study: Range finding study was not conducted.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (lot# 93297LJ and 98.9% purity) was used at a concentration of 3.2, 10, and 32 mg/L

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Less than 10% inhibition was observed at the highest tested conc.

Effect concentrations 2

Duration:

3 d

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: Less than 10% inhibition was observed at the highest tested conc., no dose related response was observed

Details on results:

- The respiration rates of the activated sludge treated with the test material at conc. between 10 to 1000 mg/L differed by less than 10% from control.

- Based on the measured inhibition rates, the 3 h EC10, EC20 and EC50 could not be quantified because up to the highest nominal test concentration of 1000 mg/L less than 10% inhibition was noted (after 3 h incubation time). No dose related response was found. No inhibition of respiration rates at a concentration of 1000 mg test material/L was found.

- If a deviation of ≤15% between test material treated activated sludge and control is considered not be an effect, the NOEC of test material will be established above 1000 mg/L (nominal).

Results with reference substance (positive control):

- Results with reference substance valid: Yes. The 3 h EC50 was 8.8 mg/L and is thus in the range of 5-30 mg/L for the used activated sludge batch.

- Other: The respiration rate of the activated sludge was moderately inhibited by 18.4% at the lowest nominal conc. of 3.2 mg/L. At the nominal conc. of 10 and 32 mg test material/L, the respiration rate was inhibited by 57.9 and 84.2% respectively.

Reported statistics and error estimates:

The 3 h EC50 including the 95% confidence limits of the reference substance was calculated by probit analysis.

Any other information on results incl. tables

Table 1: Influence of test material on oxygen consumption of activated sludge

Test concentration (mg/L)	Oxygen consumption (mg O2/L min)	Inhibition %	pH		Oxygen concentration (mg O2/L)
			Start*	End*	Start*	End*
1000	0.39	-2.6	8	8.4	8	8.2
320	0.4	-5.3	7.8	8.4	7.9	8.2
100	0.38	0	7.7	8.5	8.1	8.5
32	0.38	0	7.5	8.6	8.2	8.6
10	0.38	0	7.5	8.6	8	8.7
Positive control
32	0.06	84.2	7.5	8.6	8.3	9.2
10	0.16	57.9	7.5	8.6	8.1	9
3.2	0.31	18.4	7.5	8.6	8.1	8.5
*start and end of 3 h aeration time

Control results: The respiration rates of the two controls did not differ by more than 15%. The coefficient of variation was 1.9%. Hence, the validity criterion was fulfilled.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Less than 10% inhibition was noted up to the highest test conc. (1,000 mg/L). Hence, under the test conditions, 3h EC50 of the test substance was found to be >1,000 mg/L (nominal) in the activated sludge respiration inhibition test.

Executive summary:

A study was conducted to assess the effect of 'oils, vegetable, deodorizer distillates' on the respiration of activated sewage sludge according to OECD Guideline No. 209, EU method C.11 and US EPA Guideline OPPTS 850.6800.

Activated sewage sludge was exposed to the test substance at concentrations of 0, 10, 32, 100, 320, and 1,000 mg/L for a period of 3 h at a temperature of 19°C with the addition of a synthetic sewage as a respiratory substrate. The rate of respiration was determined after 3 h contact time and compared to data for the control and a reference substance, 3,5-dichlorophenol.  

 

Less than 10% inhibition was noted up to the highest nominal test conc. (1,000 mg/L). No dose related response was found. Thus the 3h EC10, EC20 and EC50 were higher than 1,000 mg/L. The 3 h EC50 of the reference substance was 8.8 mg/L and was thus in the range of 5-30 mg/L. The respiration rates of the two controls did not differ by more than 15% and met the validity criteria of the test.

Hence, under the test conditions, 3h EC50 of the test substance was found to be >1000 mg/L (nominal) in the activated sludge respiration inhibition test.