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Description of key information

EU risk assessment (2009), p. 46-47:
Summary of toxicokinetics, metabolism and distribution: There are no data available on the toxicokinetics, metabolism and distribution of 4-tertbutylbenzoic acid after inhalation, oral and dermal exposure in animals or humans. Taking into account the physico-chemical properties of PTBBA (molecular weight 178 g/mol, water solubility of 47.1 mg/l, log Pow of 3.4, and vapour pressure of 0.057 Pa), the state of ionisation and available toxicological information an extent of absorption of 100% via inhalation, dermal and oral exposure will be assumed.
EU risk assessment (2009), p.34:
PBT-assessment
PTBBA is according to standard ready biodegradability tests not readily degradable (Shell
Research Limited, 1984a). Other data available indicate that PTBBA might be inherently
biodegradable (see chapter 3.1.3). As the present data cannot be used to judge whether the
substance is inherently biodegradable or not, the screening P-criterion can be considered to be
fulfilled.
For PTBBA, no experimental results on bioaccumulation are available. The octanol-water
partitioning coefficient for the undissociated substance (logKow = 3.4) is below the screening
criterion logKow of 4.5. As PTBBA is present in the environmentally relevant pH-range
mainly in ionized form, bioaccumulation potential can be expected to be low. It can thus be
concluded that PTBBA does not fulfil the screening B-criterion.
Only acute data on the aquatic ecotoxicity of PTBBA are available (see chapter 3.2.1).
Information on the toxicity of organisms in other compartments has not been presented. The
lowest acute effect value (for goldfish; 96h-LC50 = 4 mg l-1) is higher than the T-screening
criterion of 0.1 mg l-1.
PTBBA fulfils the screening P-criterion, but not the screening criteria for bioaccumulation
and ecotoxicity. Therefore, PTBBA can be considered as no PBT.

Key value for chemical safety assessment

Bioaccumulation potential:
low bioaccumulation potential
Absorption rate - oral (%):
100
Absorption rate - dermal (%):
100
Absorption rate - inhalation (%):
100

Additional information

In respect of toxicokinetics, the EU risk assessment report states that the substance is likely to be fully absorbed by the body. At the same time it is not considered a PBT substance. However, the P-criterion is met as the substance is not readily biodegradable.