Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1983
Report Date:
1983

Materials and methods

GLP compliance:
yes
Test type:
other: percutaneous absorption
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
CTF is a white crystalline solid with a sweet odour and slightly basic in nature. Specific gravity 1.35g/ml at 72°C, boiling point 152°C. It is stable to light, heat, air and moisture and soluble in 50/50 v/v ethanol/water. The sample was 98.4% pure with the major impurities 3-chloro-5-trifluoromethyl pyridine (5-CTF): 0.47%, 2-chloro-3-trifluoromethyl pyridine (2-CTF): 0.44% and 3-trifluoromethyl pyridine (TF): 0.24%.
Test Substance Control Number: Y00846/013/001.

Results and discussion

Any other information on results incl. tables

Results

After application to the skin membranes of CTF as a 2.5mg/ml solution in acetone (which was allowed to evaporate away) the mean rate of absorption of CTF through human epidermal membranes was:

0.0070 mg/cm2/hr (SEM ± 0.0011 : n=11)

When similarly applied to rat whole skin the mean rate of absorption was:

0.0062 mg/cm2/hr (SEM ± 0.00008 : n = 20)

When applied to separated rat epidermal membranes the mean rate of absorption of CTF was:

0.0053 mg/cm2/hr (SEM ± 0.00096 : n=7)

The mean damage ratio due to contact of CTF with the skin membranes was:

Human epidermal membranes: 4.25 (SEM ± 2.4 : n = 3)

Rat whole skin: 2.19 (SEM ± 0.12 : n = 4)

Separated rat epidermal membranes: 4.01 (SEM ± 0.87 : n = 7)

Contact with ethanol/water (50/50 v/v) alone produces a damage ratio of ~ 2.0

Applicant's summary and conclusion

Conclusions:
2-chloro-5-(trifluoromethyl) pyridine (CTF) only penetrated both human and rat skin epidermal membranes slowly.
Executive summary:

2-chloro-5-(trifluoromethyl) pyridine (CTF) was applied in acetone (2.5mg/ml) to prepared human and rat epidermal membranes in glass diffusion cells. The mean in vitro percutaneous absorption rate of CTF was

0.0070mg/cm2/hr (SEM ± 0.011 : n = 11) through human skin

0.0053mg/cm2/hr (SEM ± 0.0096 : n = 11) through rat skin

These results indicate that CTF penetrated both these skin types slowly.