Reaction mass of 2-(1,1-dimethylethyl)-4-{[5-(1,1-dimethylethyl)-4-hydroxy-2-methylphenyl]thio}-5-methylphenyl 3-(dodecylthio)propionate and thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene] bis[3-(dodecylthio)propionate]

PBT assessment

PBT assessment: overall result

Reference

Name:

Reaction mass of 2-(1,1-dimethylethyl)-4-{[5-(1,1- dimethylethyl)-4-hydroxy-2-methylphenyl]thio}-5- methylphenyl 3-(dodecylthio)propionate and thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene] bis[3-(dodecylthio)propionate]

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

Reaction mass of 2-(1,1-dimethylethyl)-4-{[5-(1,1- dimethylethyl)-4-hydroxy-2-methylphenyl]thio}-5- methylphenyl 3-(dodecylthio)propionate and thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene] bis[3-(dodecylthio)propionate]

Reference substance:

Reaction mass of 2-(1,1-dimethylethyl)-4-{[5-(1,1- dimethylethyl)-4-hydroxy-2-methylphenyl]thio}-5- methylphenyl 3-(dodecylthio)propionate and thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene] bis[3-(dodecylthio)propionate]

PBT status:

the substance is not PBT / vPvB

Justification:

Persistence

The test item attained 0% biodegradation after 28 days and therefore cannot be considered to be readily biodegradable. The substance was found not to be readily biodegradable and 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

Screening data such as log Pow suggests that the substance can be considered potentially bioaccumulative (B/vB) on the basis of a high partition coefficient (Log Pow 6.2) however available QSAR data confirms BCF values at <2000 l/kg. Please see attached QPRF document for justification available in section 13 (Assessment reports) of this dossier.

In addition to QSAR data a BCF study is also included within this dossier for a read across substance T-1226A. The substance AO-26 is regarded as comparable with the source substance T-1226A for the purpose of read across to its bioaccumulation properties. The highest value obtained by the source substance is a BCF<31 and it is proposed to use this value also for the target substance AO-26.

Please see full read across assessment justification document attached under section 5.3.1 titled "Adeka AO-26 Bioacc-RA assessment_2019-06-28_final.

Based on this data it can be concluded that the substance is not (B/vB).

Toxicity

In the 28 day repeated dose oral toxicity study adverse effects were observed in the liver and heart of males and females receiving 100, 300 or 1000 mg/kg/day and minimal treatment-related changes in the kidneys of females receiving 1000 mg/kg/day. The microscopic changes observed in the livers and hearts were considered to be adverse, therefore we must assume the substance causes toxicity.

Based on all the information above the substance is not considered a PBT substance or a vPvB substance.