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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP Guideline Study

Data source

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

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 428 (Skin Absorption: In Vitro Method)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2-chloro-5-(trifluoromethyl)pyridine
EC Number:
257-856-5
EC Name:
2-chloro-5-(trifluoromethyl)pyridine
Cas Number:
52334-81-3
Molecular formula:
C6H3ClF3N
IUPAC Name:
2-chloro-5-(trifluoromethyl)pyridine
Constituent 2
Reference substance name:
2-chloro-5-(trifluoromethyl) pyridine
IUPAC Name:
2-chloro-5-(trifluoromethyl) pyridine
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.

Administration / exposure

Type of coverage:
open
Vehicle:
acetone

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.