4-chloro-α,α,α-trifluorotoluene

Endpoint summary

Description of key information

The elimination of the test item from the blood after intravenous injection and oral administration followed a triexponential equation with very rapid distribution in the tissues and a biological elimination half-life of about 20 hours. After oral administration of the test item via microencapsulated suspension or corn oil solution, the maximum blood levels were reached after 50 - 100 minutes or 8-11 hours respectively. The absorption hal-life was 17 minutes or 98 minutes respectively.
After oral administration of the test item via corn oil solution, a total exctretion of 79% (females) and 87% (males) was found after 4 days, but the main part (50-60%) was excreted already after 24 hours. The test item was excreted unchanged in exhalations and in faeces, while low levels of metabolites were found in urine. Only low levels of activity were found in the tissues after 4 days, mostly in adipose tissues.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

In PCBTF-exposed rats, most of the treatment dose was exhaled as unchanged PCBTF. The remainder was excreted as metabolites in the urine (dihydroxybenzotrifluoride and 4-chloro-3-hydroxybenzotrifluoride glucuronides, as well as minor amounts of a mercapturic acid conjugate) and feces. The vehicle used for oral dosing of test animals was shown to affect both the absorption rate and maximum blood concentration, but not bioavailability, distribution or elimination.

No absorption rate is available, however the maximum blood concentration was 40 microl/ml and was reached in 100 minutes or 11 hours according to the vehicle used.

From all the available studies, it is clear that the elimination of PCBTF is rapid and almost complete (up to 87% in 4 days; DT50 = less than one day). Very low levels have been found in adipose tissues. It is concluded therefore that PCBTF has no potential of bioaccumulating.