Thiosemicarbazide

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 301 C

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

no

GLP compliance:

not specified

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:Cold, dark place
- Stability under test conditions:Yes-Confirmation:Test solution Infrared absorption spectrum of test substance before start of culture and after completion of culture. As a result of measurement -Stable.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge:
Collected from 10 sea breams:
Fucho River Treatment Plant (Sapporo City, Hokkaido)
Nakahama treatment plant (Osaka prefecture Osaka city
Kitakami River (Ishinomaki-shi, Miyagi)
Yoshino River (Tokushima City, Tokushima Prefecture)
Hiroshima Bay (Hiroshima-shi, Hiroshima)
Shiba processing plant (Kashima gun, Ibaraki prefecture>
Ochiai processing plant (Shinjuku-ku, Tokyo)
Shinano river (Niigata prefecture Nishikanbara gun)
Lake Biwa (Otsu City, Shiga Prefecture)
Dokai Bay (Kitakyushu City, Fukuoka Prefecture)


- Concentration of sludge: 30 mg/L

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium:21 Of JIS K OIO2 1985.
Three ml of each liquid: Liquid A, liquid B, liquid C and liquid D were mixed with purified water (Japan Pharmacopoeia, Takasugi Pharmaceutical Co., Ltd.) to make up 1 litre.
- Test temperature: 25+-2ºC
- pH: 7+-1
- pH adjusted: yes

TEST SYSTEM
- Number of culture flasks/concentration: 6 bottles (1 bottle - test substance in water, 3 bottles- test material in medium, 1 bottle- reference substance in medium and 1 bottle - medium)
- Method used to create aerobic conditions: Stirring, magnetic stirrer.
- Test solution volume: 300 ml
- Test performed in closed vessels due to significant volatility of test substance: Yes, (Coulometer made by Okura Electric Co., Ltd)
- Test performed in open system: No


CONTROL AND BLANK SYSTEM
- Inoculum blank: bottle with medium
- Abiotic sterile control: bottle - test substance with water
- Activity control: bottle with reference substance in medium

Reference substance:

aniline

Remarks:

special grade reagent manufactured by Showa Chemical Industry Co., Ltd.)

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 0

Sampling time:

28 d

Key result

Parameter:

% degradation (TOC removal)

Value:

ca. 0

Sampling time:

28 d

Key result

Parameter:

% degradation (test mat. analysis)

Value:

ca. 0

Sampling time:

28 d

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Under the test condition, test item is not biodegradable.

Executive summary:

In accordance with GLP principles and OECD TG 301C (MITI - Ministry of International Trade and Industry, Japan) the test of aerobic biodegradability was determined. Mineral solution containing 100 mg/L of test item was inoculated with microorganisms and incubated under aerobic conditions (oxygen presence) for 28 days. The degradation was followed by the determination of oxygen uptake, TOC removal and Test material analysis. According to OECD criteria, the pass level for ready biodegradability is 60 %, test item attained 0 % of biodegradation and can be assumed as no readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

Internationally accepted calculation method EPI-SUITE EPA(USA)
1. SOFTWARE
EPI-SUITE EPA (USA)

2. MODEL (incl. version number)
BIOWIN v 4.10

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES : NC(=S)NN

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
The QMRF is available in "Attached justification".

5. APPLICABILITY DOMAIN
The QPRF is available in “Attached justification”.

6. ADEQUACY OF THE RESULT
The QPRF is available in “Attached justification”.

Guideline:

other: REACH Guidance on QSARs R.6

Principles of method if other than guideline:

Howard, P.H., Boethling, R.S., Stiteler, W.M., Meylan, W.M., Hueber, A.E., Beauman, J.A., Larosche, M.E. 1992. Predictive model for aerobic biodegradability developed from a file of evaluated biodegradation data. Environ. Toxicol. Chem. 11:593-603.

GLP compliance:

no

Specific details on test material used for the study:

SMILE:NC(=S)NN

Key result

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

other: Not ready biodegradable-QSAR prediction

Biowin1 (Linear Model):   0.9143

Biowin2 (Non-Linear Model) : 0.9879

Biowin3 (Ultimate Survey Model):  2.9436  (weeks)

Biowin4 (Primary Survey Model) :  3.9217  (days )

Biowin5 (MITI Linear Model) : 0.1947

Biowin6 (MITI Non-Linear Model): 0.0000

Biowin7 (Anaerobic Linear Model): 0.2682

Ready Biodegradability Prediction:   NO

Interpretation of results:

not readily biodegradable

Conclusions:

The substance is predicted to be not readily biodegradable (EPISUITE, BIOWINN v4.10).

Executive summary:

The substance is predicted to be not readily biodegradable (EPISUITE, BIOWINN v4.10).

Description of key information

Key study: According the National Institute of Technology and Evaluation (NITE) test item is not biodegradable under the test condition.

Supporting study: Internationally accepted calculation method EPI-SUITE EPA(USA). The substance is predicted to be not readily biodegradable (EPISUITE, BIOWIN v4.10).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Key study: According the National Institute of Technology and Evaluation (NITE) test item is not biodegradable.

Supporting study: Internationally accepted calculation method EPI-SUITE EPA(USA). The substance is predicted to be not readily biodegradable (EPISUITE, BIOWIN v4.10).