1,3-Diazaspiro[4.5]decane-2,4-dione, 8-methoxy-, sodium salt (1:1), cis-

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))

Version / remarks:

1988

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1988

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

sodium (5s,8s)-8-methoxy-2,4-dioxo-1,3-diazaspiro[4.5]decan-3-ide

EC Number:

929-513-6

Cas Number:

1400584-86-2

Molecular formula:

C9H13N2O3 · Na

IUPAC Name:

sodium (5s,8s)-8-methoxy-2,4-dioxo-1,3-diazaspiro[4.5]decan-3-ide

Test material form:

solid: bulk

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

Method: physico-chemical oxygen consumption
Controls: 3.5-Dichlorophenol, Purity 97%.
Test substance concentration: 10, 100, 1000 mg/L
Reference compound concentration: 5, 10 and 20 mg/L

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Type: mixed population of aquatic microorganisms (activated sludge)
Origin: aeration tank of a domestic sewage treatment plant (Municipal STP Cologne-Stammheim)
Date of collection: 2007-04-23

Pretreatment: aeration of the activated sludge, daily fed with synthetic medium
pH of the suspension before application: 7.4

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

19.7 - 19.8 °C

pH:

7.8 - 8.0

Dissolved oxygen:

2.5 - 5.5 mg/L

Nominal and measured concentrations:

10, 100, 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3.5-Dichlorophenol

Results and discussion

Effect concentrations

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test substance showed 0.0 % respiration inhibition of activated sludge at a test item concentration of 1000 mg/L.
The EC50 is higher than 1000 mg/L.

Executive summary:

A study was performed to assess the toxicity of bacteria.

The study was conducted in accordance with the Commission Directive 88/302/EEC; Official Journal of the EG L133 Part C. 11 (1988) and OECD Guideline 209 "Activated Sludge, Respiration Inhibition Test" (1984).

The activated sludge was exposed test substance at different concentrations. The respiration rate of each mixture was determined after aeration periods of 3 hours.

The test item showed 0.0 % respiration inhibition of activated sludge at a test item concentration of 1000 mg/L.

The EC50 is higher than 1000 mg/L.

The effect value related to nominal concentration, since no analytical monitoring was performed.