1-amidino-2-thiourea

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1-amidino-2-thiourea

EC Number:

218-308-0

EC Name:

1-amidino-2-thiourea

Cas Number:

2114-02-5

Molecular formula:

C2H6N4S

IUPAC Name:

1-(Diaminomethylidene)thiourea

Test material form:

solid: crystalline

Specific details on test material used for the study:

Manufacturer: Anhui Shindo Chemical CO. LTDSupplier: Changzou Foreign Trade Corp.Batch number: 0102A26 (20151203)Physical state: Solid, crystalline substanceColour: WhiteStorage: in a cool, dry place, protected from light

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Type of inoculum: aerobic mixed bacterial cultureSource: Municipal wastewater treatment plant, Esztergom-Kertváros, Hungary

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

PREPARATION OF INOCULUM TEST CULTUREBefore the test 300 ml stock culture was filtered through a filter with 0.2 mm pore size to remove the bigger insoluble particles and then the dry substance content of the filtrate was determined. The measured value was 3.84 g/L. For preparing the inoculum culture 147.92 ml mineral medium was added to 52.1 ml filtered stock culture. The calculated dry mass of inoculum culture was 1 g/L.PREPARATION OF REFERENCE SOLUTIONFor the reference solution 320.02 mg sodium acetate was diluted in 100 ml mineral medium.PREPARATION OF TEST VESSELSFollowing test vessels were prepared and analysed for the study:- Test item (in two replicates)- Blank control (in two replicates)- Reference solution (positive control)- Reference and test item solution (toxicity control)- Sterilized solution of test item (abiotic control)The vessels were kept in thermostat for 28 days.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

2

Remarks on result:

other: mean of two replicates

BOD5 / COD results

Results with reference substance:

Reference solution (positive control): 75%

Applicant's summary and conclusion

Interpretation of results:

not readily biodegradable

Conclusions:

According to OECD guideline the test item should be classified as readily biodegradable if the percentage biodegradation reaches 60% of theoretical oxygen demand within 28 day period in a 10-day window. Based on ready biodegradability testing results the Amidinothiourea is not readily biodegradable.