(Z)-α-[[2-(tert-butoxy)-1,1-dimethyl-2-oxoethoxy]imino]-2-(tritylamino)thiazol-4-acetic acid

PBT assessment

PBT assessment: overall result

Reference

Name:

1132 Side chain

Type of composition:

legal entity composition of the substance

State / form:

solid: bulk

Reference substance:

1132 Side chain

PBT status:

the substance is handled as if it were a PBT/vPvB

Justification:

1132 only attained 1% biodegradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301B. Formal aqueous solubility was estimated as < 0.3mg/L. This solubility was found to be below the detection limit of the analytical determination method developed to quantify the amount of sample in the aqueous phase. Therefore it is not possible to conduct EC A.8 Partition Coefficient analysis  by the shake flask method. In accordance with the test guidance the partition coefficient was estimated using prediction software (KOWWIN v1.68). The prediction software uses SMILES input to calculate the Partition Coefficient. The logKow for the substance was calculated to be 7.92.

No acute aquatic toxicity data is available as the substance is considered to be very insoluble with water solubility was below method's limit of detection (below 3.44E-6 g/L). Due to the limited solubility of the sidechain, some time was spent on developing a sample preparation that would completely dissolve all of the test material. The fact that it was necessary to dissolve the product in a strong solvent, like tetrahydrofuran or dimethyl sulfoxide (sometimes known as the universal solvent), could be considered an indication that the product has a low solubility. Based on the above results the substance would not be considered to be available to aquatic species based on the low level of solubility.

Likely routes of exposure:

As any real potential exposure to the substance is in dust form, the potential routes of exposure to humans would be by inhalation and dermal contact. However operational conditions and risk management measures are in place which minimise those routes of exposure.For the environment the substance is released to a marine estuary and therefore freshwater and microorganisms will not be exposed to the substance. The soil is also not a route of exposure as substance is only handled at one site and all wastes are collected and properly disposed of. Exposure to the air is possible but before any release it is filtered and sent through control equipment that prevent any “air” releases to the environment.