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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1987
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study according to OECD guideline 406.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
This substance has been demonstrated to be a non-sensitizer in a guideline compliant studies, therefore potency data as generated in an LLNA is not needed.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Identity: Dowanol-PnB (1-butoxy-2-hydroxypropane or
propylene glycol normal-butyl ether). CAS # 29387-86-8 (also
5131-66-8)
Batch No.: XZ 95410.00.
Purity: "More than 98%"*.
Supplied as: Not reported.
Appearance: Transparent fluid.
Administered as: Various dilutions (see below).
Specific Gravity: 0.88 g/ml.*
Solubility: 6% in water.*
Stability: Stable up to 200°C.*
* from acute oral toxicity report for PnB that used same
sample lot

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
not specified
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Wiga GmbH
- Age at study initiation: no data
- Weight at study initiation: 300-400 g
- Housing: under standard laboratory conditions (max. 5 animals per metallic cage: bottom 2544 cm2 and 38 cm height)
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C (+/- 2°C)
- Humidity (%): 40-80%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
propylene glycol
Concentration / amount:
Irritation Screen: 100%, 50%, 10% and 5%
Induction: 80%
Challenge: 40%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
propylene glycol
Concentration / amount:
Irritation Screen: 100%, 50%, 10% and 5%
Induction: 80%
Challenge: 40%
No. of animals per dose:
20 test animals & 10 control animals
Details on study design:
RANGE FINDING TESTS: Irritation screen with 5%, 10%, 50% and100%.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 hours
- Site: dorsal surface
- Frequency of applications: 3
- Concentrations: 80%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 14 days after last induction
- Exposure period: 6 hours
- Site: dorsal surface
- Concentrations: 40%
- Evaluation (hr after challenge): 24 and 48 hours
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
40%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 40%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
40%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 40%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
none
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: none.

Any other information on results incl. tables

Morbidity/Mortality: All subjects survived treatment with the test compound. 
Clinical signs: None reported. No dermal effects reported at site of application. 
Body weights: No effect on body weights reported. Macroscopic Examinations: No gross lesions recorded. Induction reactions and duration: No effects reported.

Challenge reactions and duration: At the 24-hour reading, all scores in treated animals were 0 for erythema or edema.
Scores remained 0 at the 48-hour reading.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Remarks:
Migrated information
Conclusions:
PnB did not cause contact hypersensitivity under the conditions of this test.
Classification: not sensitizing
Executive summary:

Propylene glycol n-butyl ether (DOWANOL*PnB) was tested for skin sensitization in guinea pigs by a modified Buehler test procedure. A volume of 0.3 ml of a freshly prepared solution of DOWANOL PnB in propylene glycol (p.g.) was applied on a patch to the clipped area of the skin. The patch appliance was occluded with a rubber dental dam making snug contact with the animal over the entire dorsal surface, during 6 hours. The readings were carried out after 24 and 48 hours.

The primary irritation screen indicated that an 80% solution of DOWANOL PnB in p.g. could be used for the final study. Ten male and ten female guinea pigs were treated once a week for 3 weeks. After the last induction exposure, the animals were left untreated for approximately two weeks before primary challenge. This challenge was carried out with a 40% solution of DOWANOL PnB in p.g.. Neither the test groups nor the ten animals in the control group produced a significant reaction. Under the experimental conditions used, DOWANOL PnB did not induce contact hypersensitivity in guinea pigs.