Registration Dossier

Diss Factsheets

Toxicological information

Sensitisation data (human)

Currently viewing:

Administrative data

sensitisation data (humans)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1961 - 1962
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study meets generally accepted scientific principles, acceptable for assessment, limited documentation.

Data source

Reference Type:
study report
Report date:

Materials and methods

Type of sensitisation studied:
Study type:
study with volunteers
Principles of method if other than guideline:
The test substance was evaluated for skin irritating properties in humans following a simulated use patch technique. Each test subject was patch tested before and after a 3-week simulated use period.
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Hydrocarbons, C7-C9, isoalkanes
EC Number:
Cas Number:
Molecular formula:
None available - not a single isomer - see remarks
Hydrocarbons, C7-C9, isoalkanes
Details on test material:
- Name of test material (as cited in study report): MRD-61-48 (ISOPAR C)
- Analytical purity: 100% pure commercial product


Type of population:
not specified
Ethical approval:
not specified
- Number of subjects exposed: 101
- Sex: males: 69; females: 32
- Age: males: 19 - 65; females: 21 - 69
Clinical history:
no data
no data
Route of administration:
Details on study design:
TYPE OF TEST(S) USED: patch test

- Type of application: occlusive / semiocclusive
- Volume applied: 60 µL

- Grading/Scoring system: skin response
0: no visible reaction
±: slight erythema
+: definite erythema
++: erythema and edema
+++: erythema, edema, with vesicles

- Statistical analysis: The difference between the initial response and the challenge response scores were compared by the Chi-square test of significance at the 5% probability level.

Results and discussion

Results of examinations:
- slight erythema; burning or pain sensation; dehydrating effects on the skin at the application site

- Number of subjects with positive reactions:
at initial patch: 3 (2 males; 1 female)
at open patch period: 0
at challenge patch: 3 (2 males; 1 female)
at rechallenge patch: 0
- Number of subjects with negative reactions:
at initial patch: 98
at open patch period: 101
at challenge patch: 98
at rechallenge patch: 101

Any other information on results incl. tables

The initial patch produced 3 positive responses (2 males, 1 female) indicating slight erythema. Some subjects complained of a burning or pain sensation while the patches were in contact with the skin from 4 to 6 hours. Subjects got the patches removed within one hour. Unfortunately it was not specified in the study which subjects complained about burning pains and which one the patches were prematurely taken off.

Following the initial patch there were 2895 uncovered applications to the skin of 101 subjects during the 3 week open patch period without any evidence of skin reaction. Usually observed from each daily application was the appearance of a dehydrating effect on the skin at the application site similar to that produce by solvents such as alcohol or ether following skin exposure and evaporation. No subject complained of itching or burning from the repeated daily applications to the test material.

The challenge patches were applied to approximately the same skin sites as those in the initial patch. 3 subjects (2 males; 1 female) showed positive responses indicating slight erythema according to those found in the initial patches, but not the same subjects. The subjects also complained of burning or pain sensations with the challenge patches, as with the initial patches.

34 subjects were given a second challenge (rechallenge) patch at a skin site very near the reactive skin site with precaution taken to eliminate the tightness of the patch in order to prevent pressure as much as possible. The rechallenge patches caused no flare-up of the acute reactive skin sites produced by the first challenge patches.

There was no evidence that skin sensitisation was produced by the test material.

Applicant's summary and conclusion

Under the test conditions, there was no evidence that the test material, hydrocarbons, C7-C9, isoalkanes, possesses a skin sensitizing potential.
Executive summary:

Under the test conditions, there was no evidence that the test material, hydrocarbons, C7 -C9, isoalkanes possesses a skin sensitizing potential.