Butanenitrile, 2-amino-2,3-dimethyl-

Toxicity to microorganisms

Administrative data

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-amino-2,3-dimethylbutanenitrile

Cas Number:

13893-53-3

Molecular formula:

C6H12N2

IUPAC Name:

2-amino-2,3-dimethylbutanenitrile

Details on test material:

- Name of test material (as cited in study report): Butanenitrile-2-amino-2.3-dimethyl
- Purity: 93.7 %

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

200.0 mg of the test substance was added to about 800 mL of demineralized water and stirred for about 2 hours at room temperature until the test substance was completely dissolved. After that the pH-value was measured (measured value = 9.1) and adjusted to 7.3 with 1 M sulphuric acid solution. The stock solution was made up to 1L with demineralized water. The stock solution appeared clear and no undissolved test substance was vissible.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge from the municipal wastewater treatment plant of Mannheim, Germany was collected on 23 Mar 2010 from the aeration tank of the plant. The activated sludge suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed with tap water and the suspension was adjusted to 7.5 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.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

180 min

Test conditions

Test temperature:

20 +/- 2 °C

pH:

The pH-values were measured in all test vessels. An adjustment was not necessary.

Dissolved oxygen:

Oxygen concentration during aeration: > 2.5 mg/L
Oxygen concentration immediately before measurement: > 6.5 mg/L

Nominal and measured concentrations:

Test concentrations (nominal): 62.5, 21.0, 6.9, 2.3, 0.8 mg/L and blank controls.

Details on test conditions:

- Test vessels: Erlenmeyer-vessel (nominal volume 250 mL)
- Test volume: 250 mL
- Synthetic medium: 8 mL/vessel 100-fold concentrated OECD medium
- Duration of the measurement of oxygen consumption: 8-10 min
- Number of test assays per concentration: 1

Reference substance (positive control):

yes

Remarks:

3,5 dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

180 min

Dose descriptor:

EC10

Effect conc.:

1.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

180 min

Dose descriptor:

EC50

Effect conc.:

7.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

EC20 (180min) = 2.1 mg/L
EC80 (180min) = 24 mg/L
In a former respiration inhibition test the test substance had an inhibition rate of 69% at a test concentration of 62.5 mg/L. Thus the mentioned test concentrations were selected.