4-Decenal, 9-hydroxy-5,9-dimethyl-

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:

25 September 2014

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 (Carbon and Ammonium Oxidation))

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Test type:

not specified

Water media type:

not specified

Limit test:

yes

Total exposure duration:

3 h

Test temperature:

20 ± 2 °C

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 500-mL scaled cylinders
- Aeration: yes
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per reference (replicates): 3
- Sludge concentration: 5 g/L
- Nutrients provided for bacteria: Synthetic sewage feed
EFFECT PARAMETERS MEASURED (with observation intervals if applicable): oxygen consumption
TEST CONCENTRATIONS
- Test concentrations: 100 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Table 6.1.7/1: Test results

Vessel	pH	Δ O2(mg/L)	Time (min)	Rate	% inhibition	Conc. Finale	Log (Conc)
C1	8.7	1.90	5.0	0.38	-	-	-
C2	8.5	1.90	5.0	0.38	-	-	-
C3	8.6	2.00	5.0	0.40	-	-	-
S1	8.2	2.39	5.0	0.48	-11.2	100.0	2.00
S2	8.3	2.25	5.0	0.45	-4.7	100.0	2.00
S3	8.3	2.10	5.0	0.42	2.3	100.0	2.00
R1	8.4	1.80	5.0	0.36	16.3	2.0	0.30
R2	8.4	1.80	5.0	0.36	16.3	2.0	0.30
R3	8.3	1.70	5.0	0.34	20.9	2.0	0.30
R4	8.6	0.60	5.0	0.12	72.1	25.0	1.40
R5	8.8	0.60	5.0	0.12	72.1	25.0	1.40
R6	8.6	0.50	5.0	0.10	76.7	25.0	1.40
C4	8.5	2.25	5.0	0.45	-	-	-
C5	8.4.	2.45	5.0	0.49	-	-	-
C6	8.5	2.40	5.0	0.48	-	-	-

Conditions for the validity of the test:

- The variation coefficient of the controls was 12.0%. This is within the validity range (30%)

- the EC₅₀ (3 hours) of 3,5-dichlorophenol is between 2 and 25 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The tested concentration (100 mg/L) produced inhibitions below 50%. Therefore, the EC50 (3 hours) of test item is > 100 mg/L.

Executive summary:

The effect of test substance on activated sludge from predominantly domestic sewage, treating domestic sewage only, was determined in a respiration inhibition test according to the OECD 209, EU Method C.11 and ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation).

 

The test substance was added to the test mixtures at the concentration of 100mg/L. The effect on the respiration rate was determined after three hours exposure. A control test with the reference substance 3,5-dichlorophenol yielded an EC₅₀ value within the range 2 to 25 mg/L, which is within the range prescribed by the Guideline. The validity criteria of the Guideline were fulfilled.

 

The test concentration (100 mg/L) produced the inhibitions below 50%. Therefore, the EC₅₀ value of test substance was considered to be > 100 mg/L.

Description of key information

One activated sludge respiration inhibition tests has been conducted on the registered substance. This OECD 209 studies was performed under GLP conditions and fulfills the validity criteria.

Key value for chemical safety assessment

EC50 for microorganisms:

100 mg/L

Additional information

The effect of test substance on activated sludge from predominantly domestic sewage, treating domestic sewage only, was determined in a respiration inhibition test according to the OECD 209,EU Method C.11 andISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation).

 

The test substance was added to the test mixtures at the concentration of 100mg/L. The effect on the respiration rate was determined after three hours exposure. A control test with the reference substance 3,5-dichlorophenol yielded an EC₅₀value within the range 2 to 25 mg/L, which is within the range prescribed by the Guideline. The validity criteria of the Guideline were fulfilled.

 

The test concentration (100 mg/L) produced the inhibitions below 50%. Therefore, the EC₅₀value of test substance was considered to be > 100 mg/L.