2-Oxetanone, 3-C14-16-alkyl 4-C15-17-alkylidene derivs.

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:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Two documents, one reprint of the report with validation and one containing raw data. OECD Guideine for Testing of Chemicals 209 - Activated sludge, respiration inhibition test, 150 8192 Water quality - Test for inhibition of oxygen consumption by activated sludge. Insufficient details on identity and composition. Test duration is 30 minutes. Raw data document is of poor quality (hard to read).

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

Basoplast 20 konz.
Stearyldiketen
C36O2H69
Mol weight: 533 g/mole
low water solubility

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

Local laboratory source
Sample taken 16 May 1989
Concentration: 5 g/L in original sludge, diluted to 1 g/L in the test

Test type:

static

Water media type:

freshwater

Total exposure duration:

30 min

Test temperature:

20-25 C

Nominal and measured concentrations:

Nominal conc: 1000 mg/L and possibly another concentration for which no O2 consumption data were given in the report

Details on test conditions:

8 ml synthetic medium, 50 ml inoculum, 1 g/L dryweight of sludge, 250 ml test volume

250 mg test substance/250 ml test volume = 1000 mg/L

Reference substance (positive control):

no

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

Control (without test substance): 20 mg/Lxh
Test sample: 21 mg/Lxh (= +5%)

Respiration rate 30 mins:

Blank: 20 mg/Lxh

1000 mg/L: 21 mg/Lxh, compared to blank 5% difference.

Validity criteria fulfilled:

not specified

Conclusions:

Author of reprint considers a validity score of 2, but essential information is lacking.

Executive summary:

A study was performed according to OECD 209 and ISO 8192 to study the inhibition of the respiration of Basoplast 20 konz. in the activated sludge respiration test by measurement of the oxygen consumption rate of aerobic micro-organisms (activated sludge) after short term exposure. Activated sludge from a laboratory waste water treatment plant using municipal sewage (1 g/L dry matter) was exposed for 30 min, after which the respiration rate was determined. Results showed a difference in respiration rate of 5%.

Description of key information

A study was performed according to OECD 209 and ISO 8192 to study the inhibition of the respiration of Basoplast 20 konz. In the activated sludge respiration test by measurement of the oxygen consumption rate of aerobic micro-organisms (activated sludge) after short term exposure. Activated sludge from a laboratory waste water treatment plant using municipal sewage (1 g/L dry matter) was exposed for 30 min, after which the respiration rate was determined. Results showed a difference in respiration rate of 5%.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

In the reported study exposure time was 30 minutes, this is not in agreement with the current guidelines. In addition to this test, also data from the available readily biodegradation test (BASF 2003) indicate that the substance has no inhibitory effect on bacterial growth (toxicity control degradation > 25%).