(Z)-4-[C11-13 (branched) alkylamino]-4-oxo-2-butenoic acid

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST SUBSTANCE
- The test substance was added in the required amounts according to the test concentrations directly to the test vessels with about 234 mL demineralized water.

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Inoculum: activated sludge from the municipal wastewater treatment plant of Mannheim, Germany, was collected from the aeration tank of the plant.
- Preparation of inoculum: activated sludge suspension was sieved with fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. On the next day the sludge suspension was washed once with tap water and the suspension was adjusted to 3 g/L dry matter. An aliquot of this suspension was added to the test vessels to obtain a sludge concentration of 1.5 g/L dry substance.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

180 min

Test temperature:

20.3 – 20.6 °C

pH:

7.0 - 8.0

Nominal and measured concentrations:

- Concentrations tested (nominal): 1000, 500, 250, 125 and 62.5 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessels: glass beakers (nominal volume 1 L)
- Test volume: 500 ml
- No. of replicates/control: 4
- No. of replicates/concentration: 2
- No. of replicates/reference: 2
- Synthetic medium: 16 ml/test vessel of 100-fold concentrated OECD medium

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Duration:

180 min

Dose descriptor:

EC10

Effect conc.:

110 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

180 min

Dose descriptor:

EC50

Effect conc.:

750 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

180 min

Dose descriptor:

other: EC80

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:

- The mean oxygen uptake of the blank controls was 16 mg/g*h

Results with reference substance (positive control):

EC50 = 8.3 mg/L

Description of key information

The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations.

Additional information

The acute toxicity of the test substance to microorganisms has been examined in a GLP guideline study according to OECD 209 with activated domestic sludge from a municipal wastewater plant [BASF SE 2012]. At test termination after 180 min, an EC10 of 110 mg/L (nominal) was determined.