Di(benzothiazol-2-yl) disulphide

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

according to guideline

Guideline:

OECD Guideline 305 C (Bioaccumulation: Test for the Degree of Bioconcentration in Fish)

Deviations:

not specified

GLP compliance:

not specified

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: every two weeks, n=2, control fish analysis: before the initiation and the termination of exposure, n=2
- Sampling intervals/frequency for test medium samples: twice a week, n=1

Vehicle:

not specified

Details on preparation of test solutions, spiked fish food or sediment:

It is necessary to prepare a solution of the test substance 100 times highly concentrated than that in the aquarium. If the test substance is not soluble enough in water, suitable solubilisers were used. More detailled information is not available for the substance tested .

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Supplier: Sugishima fish farm, Japan
Weight: about 30g, Length: about 10 cm, Lipid content: 2-6 % (at the initiation of exposure)

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Test temperature:

25+-2°C

Dissolved oxygen:

6-8 mg/L

Details on test conditions:

Test tank: 100L glass tank
Number of fish: 15-20 fish/Level
Renewal rate of test solutions: flow rate 200-800 mL/min

Nominal and measured concentrations:

Considering of the result of preliminary test for 48-hr LC50 and analytically detecting limit of the test substance, test concentrations were decided.
0.2 and 0.02 mg/l

Lipid content:

> 2 - < 6 %

Time point:

start of exposure

Type:

BCF

Value:

>= 1 - <= 7.2

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.2 mg/l

Type:

BCF

Value:

1.4 - 51

Basis:

whole body w.w.

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:0.02 mg/l

Calculation of bioconcentration factor

BCF = concentration of test substance in fish/concentration of test substance in water

Conclusions:

The highest obtained BCF value was 51 at a concentration of 0.02 mg/l.

Executive summary:

The highest obtained BCF value was 51 at a concentration of 0.02 mg/l (MITI 1992).

Description of key information

The highest obtained BCF value was 51 at a concentration of 0.02 mg/l and the

method used corresponds to the OECD Guideline 305C ((MITI 1992). Because the measured BCF value is much lower than 100, MBTS is considered as not bioaccumulative. As the potential metabolites of MBTS, such as MBT, BT, BTon and MeSBT are also not bioaccumulative.

Additional information

QSRA results of BCF for MBTS are also mentioned in the appendix B of EU-Risk Assessment for CBS (CAS: 95 -33 -0): - BCF of 1330 estimated using log Pow of 4.5 (Veith et al., 1979) - BCF of 528 (BCFWIN 2.15) These results are considerably different from the experimental result. Although only a general description of the test procedure is given without mentioning experimental details in the reference from MITI, experimental result based on OECD guideline is still preferred to QSRA estimation.