Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

basic toxicokinetics
Adequacy of study:
other information

Data source

Materials and methods

Objective of study:
other: Assessment of toxicokinetic behaviour

Results and discussion

Any other information on results incl. tables

Toxicity studies have shown no evidence for absorption
following oral administration.

Although there was no evidence of any dermal penetration in
the rat and rabbit, following occluded application, the
positive dermal sensitisation result in the guinea pig
demonstrated that some test substance was absorbed through
the skin in this species.

The results of the air elutriation study showed that the
test substance was of low respirability, with only 0.22% of
an inhaled dose capable of penetrating lower than the
nasopharyngeal region.

An assessment of potential absorption is also based upon its
physico-chemical properties, which suggest that the intact
molecule would be subject to some absorption across the
gastrointestinal mucosa following oral administration.

The poor aqueous solubility would promote biotransformation
of any absorbed molecule, because the intact molecule would
be unlikely to be excreted directly in urine.  One of the
three equivalent methyl groups on the tertiary butyl moiety
is subject to progressive oxidation to the alcohol and
carboxylic acid, both of which may be excreted either
conjugated or non-conjugated.  However, the whole butyl
group is more likely to be cleaved to leave a carboxylic
acid which would increase the polarity of the molecule,
thereby promoting urinary excretion.  Other methyl groups
may also be oxidised and conjugated similarly. Hydroxylation
of the fluorophenyl ring would also increase the polarity of
the molecule.  Any metabolites eliminated via bile would be
excreted in faeces with the unabsorbed dose.

Applicant's summary and conclusion