3-(Hydroxymethyl)-1-pentene

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:

12.12.2006-26.02.2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1988

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

1984

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

A stock solution with the concentration of 100 mg/L was prepared.

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: sewage plant Darmstadt, Germany

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

18 - 20°C

pH:

7.2 - 8.5

Dissolved oxygen:

8.3 - 8.7 mg/L

Nominal and measured concentrations:

Nominal concentrations: 10, 32, 100, 320, 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol, 3.2, 10, 32 mg/L

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

ca. 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Key result

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

ca. 108 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95%CI: 7.0 - 254.5 mg/L

Details on results:

Based on inhibition rates, no EC50 could be calculated due to mathematical reasons. Since the maximum respiration inhibition was mesured to be about 50% at 1000 mg/L, the EC50 is proposed to be 1000 mg/L.

Results with reference substance (positive control):

3h-EC20 3.2 mg/L
3h-EC50 9.7 mg/L

Percentages of Inhibition:

Nominal concentration [mg/L]	Inhibition [%]
1000	51.4
320	24.3
100	18.9
32	13.5
10	8.1

 

Validity criteria fulfilled:

yes

Conclusions:

The NOEC was determined to be 100 mg/L and the EC50 to be ca. 1000 mg/L.

Executive summary:

Study design

A test on respiration inhibition of domestic sewage sludge was conducted according to OECD 209 and commission directive 88/302/EEC. The influence of the test item Art. 278718 (Ethyl-Butenol) on the activity of activated sludge was evaluated by measuring the respiration rate under defined conditions. The respiration rate (oxygen consumption) of an aerobic activated sludge fed with a standard amount of synthetic sewage was measured in the presence of various of 10, 32, 100, 320 and 1000 mg/L of the test item after an incubation period of 3 hours.

Results

In comparison to the inoculum controls the respiration rate of the activated sludge was slightly inhibited by about 8% at the lowest nominal test concentrations of 10 mg/L. At the next higher concentrations of nominal 32, 100, 320 and 1000 mg/L, a dose related inhibition of the respiration rate was found. At 1000 mg/L, an inhibition of about 51 % was measured. Concentrations exceeding 1000 mg/L nominal were not tested. Based on measured inhibition rates, no EC50 could be determined due to mathematical reasons. The EC20 was calculated to be 108 mg/L. The confidence limits were 7.0 mg/L and 254.5 mg/L for the lower and upper range respectively. Since the maximum respiration inhibition was measured to be about 50% at a test concentration of 1000 mg/L, the EC50 is proposed
to be 1000 mg/L. A NOEC can be established at 100 mg/L since the respiration inhibition was less than 20% at this concentration.

Conclusion

After 3 hours of exposure, the NOEC was determined to be 100 mg/L and the EC50 to ca. 1000 mg/L.

Description of key information

The NOEC was determined to be 100 mg/L and the EC50 to be ca. 1000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

A test on respiration inhibition of domestic sewage sludge was conducted according to OECD 209. After 3 hours of exposure, the NOEC was determined to be 100 mg/L and the EC50 to be ca. 1000 mg/L.