3-(amidinothio)propionic acid

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with restrictions: The total exposure duration was 30 minutes only.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

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

Principles of method if other than guideline:

according to Annex of EG Directive 88/302/EWG

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3-(amidinothio)propionic acid

EC Number:

226-430-0

EC Name:

3-(amidinothio)propionic acid

Cas Number:

5398-29-8

Molecular formula:

C4H8N2O2S

IUPAC Name:

3-(carbamimidoylsulfanyl)propanoic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Carboxyethylisothiuroniumbetain
- Physical state: powder
- Analytical purity: > 98%
- Lot/batch No.: 88-3054

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was directly added to the test vessels.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Laboratory culture: laboratory wastewater plant with municipal sewage
- Initial biomass concentration: 1g/L

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test conditions

Test temperature:

20 ± 2 °C

Nominal and measured concentrations:

Nominal: 250, 500 and 1000 mg/L

Details on test conditions:

TEST SYSTEM
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: OECD medium

EFFECT PARAMETERS MEASURED: Oxygen consumption after 30 minutes exposure time.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

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

Effect concentrations 2

Duration:

30 min

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

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC20 = 4 mg/L, EC50 approx. 29 mg/L, EC80 > 100 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test substance did not show to inhibit aquatic microorganisms. Thus, the inhibition of the degradation activity of activated sludge in STPs is not anticipated.