(1,2-dioxoethylene)bis(iminoethylene) bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]

PBT assessment

PBT assessment: overall result

Reference

Name:

(1,2-dioxoethylene)bis(iminoethylene) bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]

Type of composition:

legal entity composition of the substance

State / form:

solid: particulate/powder

Reference substance:

(1,2-dioxoethylene)bis(iminoethylene) bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]

PBT status:

the substance is not PBT / vPvB

Justification:

The following information is available for review:

Persistence

The substance is not readily biodegradable achieving 0-2% in 28 days. Due to high water insolubility (1.5 μg/l), it is not possible to assess the potential for hydrolysis by testing. The substance is, however, a stable organic molecule and is, therefore, considered to not potentially hydrolyse in the environment. 

The substance potentially screens as persistent.

 

Bioaccumulation

The log Pow has been determined to be 8.1. The substance is highly insoluble in water (1.5 μg/l). The high log Pow is likely to be due in part to the hydrophobic nature of the molecule but is well outside the criteria by which that substance is considered to present a potential hazard.

The substance has a water solubility of 1.5 μg/l which clearly limits the bioavailability towards aquatic organisms. Furthermore, due to the high adsorption potential (log Koc > 5.63) it is expected that the substance will bind to sewage sludge and be removed from the water phase. In total, the concentrations in the environmental water phase are expected to be very low and not relevant for bioaccumulation.

The calculated BCF value is 713.4 L/kg wet-wt estimated by QSAR modelling. These values support the above-mentioned assessment that the substance is not expected to significantly accumulate in aquatic organisms.

No evidence of accumulation was noted in the repeated dose study conducted on the substance.

The substance does not screen as "B" based on the high log Kow value and calculated BCF.

 

Toxicity

The substance is highly insoluble in water. In consequence exposure to three aquatic species (algae, daphnia and fish) have been investigated at nominal concentrations. The toxicological examination of freshwater fish, daphnia and algae provided the following results:

·        LC50 > 100 mg/l in fish

·        EC50 > 100 mg/l in daphnia

·        EC50 > 100 mg/l in algae

The substance is not classified on the basis of these results and no further toxicological examination is considered appropriate to determine that hazard of the substance.

 

The substance has been assessed for genetic toxicity utilising in vitro assays with and without metabolic activation. All endpoints demonstrated a lack of mutagenic response.

 

The reproduction/developmental screening test provided a result NOAEL 1000 mg/kg bw/day and showed no substance related effects on parents or offspring.

 

On the basis of the genetic and reproduction/developmental toxicity data available, in addition to the repeated dose toxicity data the substance is not classified for this endpoint.

 

The data from the 90-day mammalian toxicity oral repeated dose study achieved a NOAEL >2000 mg/kg/day. The substance is not classified on the basis of this data and no further toxicological examination is considered necessary for hazard assessment.

 

The substance demonstrates no toxicity in any of the test endpoints noted.

 

Conclusion.

The substance does not screen as PBT of vPvB on the basis of the available data.