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Classification & Labelling & PBT assessment

PBT assessment

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PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

The substance is not considered a PBT or vP/vB substance based on the following rationale:

Persistence

Reliable studies are available to demonstrate that terephthalic acid is readily biodegradable. Terephthalic acid may therefore be expected to degrade rapidly, and to be completely mineralised,i.e. converted to CO2 and H2O without forming any recalcitrant metabolites. Terephthalic acid and its degradation intermediates are non-persistent. Terephthalic acid is expected to degrade rapidly under anaerobic as well as aerobic conditions.

Bioaccumulation

QSAR-predicted and measured log10 Kow values for terephthalic acid are less than 3.0. The potential for terephthalic acid to bioaccumulate in the tissues of organisms that inhabit aquatic or terrestrial matrices contaminated with TPA is therefore negligible. The risk that terephthalic acid may biomagnify through successive trophic levels of aquatic or terrestrial food chains is consequently also negligible. 

Toxcity

Three reliable, GLP-compliant short-term studies are available in which TPA was treated with NaOH solution to convert the free acid to its highly soluble sodium terephthalate salt(s) prior to exposure to fish, daphnia and algae. No adverse effects occurred in these studies, up to and including the highest nominal TPA-equivalent concentrations of 1000 mg/L. The lowest endpoint from these three studies (the 72 -h ErC50 for growth inhibition of D. subspicatus) was >668 mg TPA-equiv/L (mean measured). These studies demonstrate the low intrinsic toxicity of terephthalate to aquatic biota, and - taking into account its susceptibility to rapid biodegradation - provide assurance that terephthalic acid does not present a long-term and/or delayed danger to the structure and/or functioning of aquatic ecosystems. 

Further to this the substance is not classified based on carcinogenicity or toxicity to reproduction.