Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

aug - dec 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

EC Number:

283-381-8

EC Name:

Bis[bis(3,5,5-trimethylhexyl)dithiocarbamate-S,S']zinc

Cas Number:

84604-96-6

Molecular formula:

C38H76N2S4Zn

IUPAC Name:

bis({[bis(3,5,5-trimethylhexyl)carbamothioyl]sulfanyl})zinc

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity > 99%
BN 1120039.2
Expiry july 2013

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):
- Laboratory culture: mixed population of activated sewage sludge from Aeration stage of Severn Trent water sewaqge plant, Leicestershire
- Method of cultivation:
- Storage conditions:
- Storage length:
- Preparation of inoculum for exposure: activated sewage sample was washed three times to remove any excessive amounts of undissolved organic carbon. The washed sample was then maintained on continuous aeration in lab at constant temp of 21°C
- Pretreatment:
- Concentration of sludge: suspended solids concentration was equal to 3.4g/l
- Initial cell/biomass concentration:
- Water filtered: yes/no
- Type and size of filter used, if any:

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 10 other: mg Carbon/L

Based on:

IC (inorganic carbon)

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

CO2 evolution

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

inorg. C analysis

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

pre-solubility work was carried out. From the pre-study it was concluded that the best method of preparation was by dispersing the test item in the test system, with aid of high shear mixing.

Test performance:

test was valid.
IC content of test item was < 5% of the Total Carbon ( satisfied criteria)
The difference between the values for CO2 production was < 20% for replicate vessels
toxicty control attained 41% degradation after 14 days and 56% degradation after 28 days, thereby confirming test item was non toxic to sewage microbes used in study.

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

ca. 0

Sampling time:

2 d

Remarks on result:

other:

Any other information on results incl. tables

table 2 attached shows the percentage biodegradation values for refeerence control, test item and combined.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item attained 0% degradation after 28 days, therefore cannot be considered to be ready biodegradable under the strict terms of the OECD 301B guideline