1,3-bis(2,4,4-trimethylpentan-2-yl)trisulfane

PBT assessment

PBT assessment: overall result

Reference

Name:

DAILUBE IS-30

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

DAILUBE IS-30

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence

A screening test for ready biodegradability determined that DAILUBE IS-30 was not readily biodegradable under test conditions (please refer to section 5.2.1). Hydroylsis testing was not feasible on the basis of poor water solubility.
In the absence of any data to the contrary it must be assumed the substance possesses P or vP properties.

Bioaccumulation

The screening criteria indicates the substance may be bioaccumulative or very bioaccumulative based on the Log Kow value which is >6.2 however a prediction for bioaccumulation was concluded based on a weight of evidence approach including QSAR data and a bioaccumulation study on a similar substance.

In the bioaccumulation study on test substance di-tert-nonyl polysulfide the degree of bioconcentration of the test substance in common carp shown in terms of BCF was ≤0.3 - 1.2 at Level 1 and ≤3.3 at Level 2.

The prediction of the potential for bioaccumulation of DAILUBE IS-30 was performed with VEGA NIC 1.1.5 (CAESAR, Meylan), ToxRead 0.23 beta, BCFBAF 3.01 (EpiSuite) and US EPA T.E.S.T. 4.2.1.
Please see table below for Bioaccumulation results:

 

Software	Model	Predicted log10BCF	Predicted BCF (L/Kg)	Reliability
T.E.S.T. 4.2.1	Consensus	2.67	465.04	1
	CAESAR 2.1.14	2.16	144	1
VEGA 1.1.5	Meylan 1.03	2.14	139	1
	KNN/Read Across 1.1.0	No Prediction	No Prediction	0
EPI Suite 4.11	BCF/BAF v3.01	2.144	139.5	2
TOXREAD 0.23beta	IRFMN rule set for BCF	Not possible	Not possible	0
	Average of nearest compounds **	2.815	653.1	1

 

It has been shown that there are significant deficiencies in most of the prediction models used in this assessment when considered individually. The various deficiencies within each are discussed above and in the QPRFs and model printouts below. There is a strong argument to consider the VEGA models as unreliable. However when considered alongside the other models reported upon above and in table 2, it can be seen that these results are within the range of results identified with the other models. Overall there is a range of results established from 139.5 L/Kg, to 653.1 L/Kg, with the most reliable result from BCF/BAF being 465.04 L/Kg.

The bioaccumulation study on test substance di-tert-nonyl polysulfide the degree of bioconcentration of the test substance in common carp shown in terms of BCF was ≤0.3 - 1.2 at Level 1 and ≤3.3 at Level 2.

Together these values show that there is a weight of evidence to suggest that the BCF for DAILUBE IS-30 should be below the threshold value for assessment of 2000 L/Kg, and therefore not bioaccumulative.

For Bioaccumulation it can be concluded the substance is not Bioaccumulating based on the available data.

Toxicity

No long term aquatic toxicity data are available however no toxicity was seen at any trophic level during acute aquatic toxicity testing. There are no data available to assess carcinogenicity. For mutagenic effects all in-vitro studies were concluded negative. In the reproductive toxicity
screening study no reproductive effects were seen and no development effects were seen. There was no evidence of any significant organ damage during the 28day repeat dose oral study .

Based on the data above the substance does not meet criteria for T properties.

Overall it is concluded that the substance is not a PBT substance or a vPvB substance.