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Toxicological information

Sensitisation data (human)

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Administrative data

Endpoint:
sensitisation data (humans)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
1972-02-11 to 1972-04-26
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non GLP, and no guideline available. However, material/methods and results were well documented, and a sufficient number of subjects were included in the test.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1972
Report Date:
1972

Materials and methods

Type of sensitisation studied:
skin
Study type:
study with volunteers
Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Under controlled conditions the material was applied under occluded conditions and subsequently evaluated to determine if it was capable of eliciting visible skin changes consistent with criteria deemed characteristic of a primary skin irritant, fatiguing agent, or a sensitizer in 50 subjects.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
- Name of test material (as cited in study report): propylene carbonate
- Physical state: clear liquid

Method

Type of population:
general
Ethical approval:
not specified
Subjects:
- Number of subjects exposed: 50
Controls:
untreated skin on each exposed subject
Route of administration:
dermal
Details on study design:
TYPE OF TEST(S) USED: repeated insult patch test


ADMINISTRATION
- Type of application: occlusive
- Description of patch: The treated area was covered with lintine gauze (3cm x 3cm). The lintine, in turn, was covered with polypropylene, the edges of which were then affixed to the skin with tape to seal the contents completely.
- Vehicle / solvent: water
- Concentrations: 10 weight %
- Volume applied: 1.0 ml/9.0 sq. cm (approx)
- Testing/scoring schedule: At the end of 24 hours, the patches were removed. The contact sites were examined and the observations were assigned scores according to criteria described under Grading (see below). Following removal, the contact sites were left untreated and uncovered and allowed to rest. At the end of the rest period, they were re-examined to ascertain whether there were any changes. Observations were recorded. The choice of contact site for the 2nd and subsequent applications depended on the condition of the previous site after the rest period. Thus, if no irritation was observed at this time, the test substance was reapplied to the same site. If, however, irritation was observed at this time, the test substance was applied to a new site.
The above procedure was adapted to a weekly routine consisting of:
1. Application of patches on Mondays, Wednesdays and Fridays.
2. Removal of patches after 24 hour contact periods on Tuesdays, Thursdays and Saturdays, respectively.
3. Rest period of 24 hours following the Tuesday and Thursday removals, and 48 hours following the Saturday removals.
After removal of the last application (No. 15) preceding the challenge, the sites were examined immediately and once daily for at least two days.
The challenge was applied to the original contact site after 14 days of no contact with the test substance. The challenge application was terminated after 24 hours. The sites were examined for immediate reaction which, if present, were graded and recorded. The sites were re-examined 24 and 48 hours later for delayed reactions.


EXAMINATIONS
- Grading/Scoring system: See below

Results and discussion

Results of examinations:
Skin changes accompanying application No. 1- No visible skin changes signifying reaction to injury were observed in any of the 50 subjects.
Skin changes accompanying application Nos. 2 through 15- No visible skin changes signifying reaction to injury were observed in any of the 50 subjects.
Skin changes accompanying challenge application-No visible skin changes signifying reaction to injury were observed in any of the 50 subjects.

Applicant's summary and conclusion

Conclusions:
Under completely occluded conditions, 10 Wt. % of propylene carbonate in water, was not capable of eliciting visible skin changes consistent with the criteria deemed characteristic of a primary irritant, fatiguing agent, or sensitizer in any of the 50 subjects.
In the opinion of the investigator, the test substance at a concentration of 10 Wt. % may be considered safe to use in contact with the skin insofar as primary irritation, fatiguing reactions, or sensitization are concerned if the conditions of contact do not exceed those of the test procedure.
Insofar as sensitization is concerned, the extrapolation of these results to a general population is limited statistically by the number of test subjects. In this case since 50 subjects were used, it may be predicted with 95 % certainty that at least 92.89 % of a general population will not be sensitized by this substance.