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Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP lab following OECD guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Glycerol formal
IUPAC Name:
Glycerol formal
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): glycerol formal
- Analytical purity: 99.9840%
- Isomers composition: CAS 4740-78-7 + 5464-28-8 (ratio ~ 50/50)
- Lot/batch No.: 1206191600R
- Expiration date of the lot/batch: 19 June 2015

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: CEGAV, Argenvilliers, France.
- Age and weight at study initiation: at the beginning of the study, the animals were 4 to 5 months old and had a mean body weight of 3807 g (range: 3485 g to 4185 g)
- Housing: The animals were individually housed in inox cages (Pajon, 75 cm x 57 cm x 50 cm). The cages were suspended in batteries over trays with absorbant paper and each cage contained a platform and enrichment (dumbbell).
- Diet and water (e.g. ad libitum): All animals had free access to pelleted breeding diet "type 110C", batch Nos. 12044 and 12102, (SAFE,
Augy, France) and to tap water (filtered using a 0.22 μm filter) contained in bottles.
- Acclimation period: the animals were acclimated to the study conditions for a period of at least 5 days before treatment.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 12 cycles/hour of filtered, non-recycled air.
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Controls:
other: During each exposure time, a dry gauze pad was applied to the opposite flank, in order to check that no alteration of the skin is induced by the semi-occlusive dressing and restraining bandage.
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 ml
Duration of treatment / exposure:
Animal 1: 3-minute, 1-hour and 4-hour exposure
Animals 2 and 3: 4-hour exposure
Observation period:
till 6 days
Number of animals:
3
Details on study design:
TREATMENT
Preparation of the animals
On the day before treatment, two or four areas of skin (3.5 cm x 5 cm) were closely clipped using electric clippers on the right and left anterior and/or posterior flanks of animals.
Care was taken to avoid damaging the skin.

Study design
Rationale for design selection
The sequential study design was as follows.
The test item was applied for 3 minutes on the skin of a single animal (Y30791):
as no full thickness destruction of skin tissue was observed in the first hour after removal of the pad, the test item was applied on another treatment site for 1 hour.

After the 1-hour application on animal Y30791:
. as no full thickness destruction of skin tissue was observed in the first hour after removal of the pad, the test item was applied on another treatment site for 4 hours.

After the 4-hour application on animal Y30791:
. as mean value from grading at 24, 48 and 72 hours after patch removal was < 2.3 for erythema or for edema, the test item was applied on the skin of two other animals for 4 hours (Y30792 and Y30793).

For each animal, the day of dose application was recorded as day 1 of its observation period.

In animal Y30791, the treatment sites are detailed in the following table:
Left flank Anterior 3-minute exposure: 3-minute exposure
Right flank Anterior 3-minute exposure: 1-hour exposure
Left flank Posterior untreated
Right flank Posterior: 4-hour exposure

In other animals (Y30792 and Y30793), the treatment sites are detailed as:
Left flank Posterior: untreated
Right flank Posterior: 4-hour exposure

Application
The test item was placed on a gauze pad, which was then applied to a skin area of approximately 6 cm2. A dosage-volume of 0.5 mL/flank was used.
During each exposure time, a dry gauze pad was applied to the opposite flank, in order to check that no alteration of the skin is induced by the semi-occlusive dressing and restraining bandage. The untreated flank acted as control.
The gauze pad was held in place by a non-irritating semi-occlusive dressing and a restraining bandage. After required period of contact with the skin, the dressing was removed.
After removal of the dressing applied for 3 minutes, any residual test item was wiped off by means of a dry cotton pad.
No residual test item was observed on removal of the dressing applied for 1 hour and 4 hours.

CLINICAL EXAMINATIONS

Morbidity and mortality
Each animal was checked for mortality or morbidity once a day during the treatment and observation periods.

Clinical signs
Each animal was observed once a day, at approximately the same time, for the recording of clinical signs.

Examination of cutaneous reactions
For each exposure period, cutaneous reactions were evaluated approximately 1 hour, 24, 48 and 72 hours after removal of the dressing. After a 3-minute, 1- and 4-hour exposure, since there was no evidence of irritation after 72 hours in male Y30791, the evaluation of cutaneous reactions was stopped. After a 4-hour exposure, since there were persistent irritation reactions at 72-hour reading in males Y30792 and Y30793, the evaluation of cutaneous reactions was extended up to the complete reversibility (at the latest day 6).

Body weight
The body weight of each animal was recorded on the day of treatment and at the end of the evaluation of cutaneous reactions (for males Y30791 and Y30793) or the next day (i.e. on day 7) for male Y30792.

SCORING SYSTEM:
Dermal irritation was graded in each animal according to the following scoring scale:
Erythema and eschar formation:
. no erythema....................................................................................................................... 0
. very slight erythema (barely perceptible)..................................................................... 1
. well-defined erythema..................................................................................................... 2
. moderate to severe erythema......................................................................................... 3
. severe erythema (beet redness) to slight eschar formation (injuries in depth) .... 4
Edema formation
. no edema............................................................................................................................ 0
. very slight edema (barely perceptible)........................................................................... 1
. slight edema (edges of area well-defined by definite raising) ................................... 2
. moderate edema (raised approximately 1 millimeter) ................................................ 3
. severe edema (raised more than 1 millimeter and extending beyond area
of exposure) ........................................................................................................................ 4
Any other cutaneous lesions were noted.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #3
Remarks:
Y30793
Time point:
72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: day 5
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: 1 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 5 days
Irritation parameter:
erythema score
Basis:
animal #2
Remarks:
Y30792
Time point:
other: 1h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: day 6
Remarks on result:
other: performed on the posterior right flank of the animal
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: day 6
Remarks on result:
other: performed on the posterior right flank of the animal
Irritation parameter:
erythema score
Basis:
animal #3
Remarks:
Y30793
Time point:
24 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: day 5
Remarks on result:
other: performed on the posterior right flank of the animal
Irritation parameter:
erythema score
Basis:
animal #3
Remarks:
Y30793
Time point:
48 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: day 5
Remarks on result:
other: performed on the posterior right flank of the animal
Irritation parameter:
edema score
Basis:
animal: #1, 2 and 3
Time point:
24/48/72 h
Score:
0
Max. score:
4
Reversibility:
other: notrelevant and no edema was recorded
Remarks on result:
other: performed on the posterior right flank of the animal
Irritation parameter:
erythema score
Basis:
animal #1
Remarks:
Y30791
Time point:
other: 3 minutes
Score:
1
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: performed on the anterior left flank of the animal in order to assess the absence of destruction of the skin
Irritation parameter:
erythema score
Basis:
animal #1
Remarks:
Y30791
Time point:
other: 1 hour
Score:
1
Max. score:
4
Reversibility:
fully reversible
Remarks on result:
other: performed on the anterior right flank of the animal in order to assess the absence of destruction of the skin
Irritant / corrosive response data:
please refer to table in "irritation/corrosion" results
Other effects:
None other effects were recorded

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the experimental conditions of this study, the test item, Glycerol formal, was slightly irritant when applied topically to rabbits.
However, the test item is not classified as irritating to skin according to the criteria of CLP Regulation.
Executive summary:

The objective of this study was to evaluate the potential corrosive and irritant properties of the test item, Glycerol formal, following dermal application on rabbits.

 

Methods

The test item, Glycerol formal (batch No. 1206191600R), was first applied for periods of 3 minutes, 1 hour and 4 hours to a single male New Zealand White rabbit.

After the 4-hour application, since the mean value from grading at 24, 48 and 72 hours after patch removal is < 2.3 for erythema or for edema, the test item was applied on the skin of two other animals for 4 hours. A dosage-volume of 0.5 mL/flank was used.

The test item was placed on a gauze pad which was then applied to a skin area of approximately 6 cm2. The gauze pad was held in place by a non-irritation semi-occlusive dressing and a restraining bandage. After required period of contact with the skin, the dressing was removed.

Each animal was observed at least once a day for mortality and clinical signs. For each exposure period, cutaneous reactions were evaluated approximately 1 hour, 24, 48 and 72 hours after removal of the dressing and then daily until the reversibility of cutaneous reactions. The mean values of the scores for erythema and edema were calculated for each animal. Body weight was recorded at the beginning and the end of the observation period or the next day for one male.

On completion of the observation period, the animals were used subsequently for the evaluation of the ocular irritation potential of the same test item.

 

Results

No unscheduled deaths occurred during the study and no clinical signs were noted in any animals. The body weight of the animals was unaffected by the test item treatment.

After a 4-hour exposure, a very slight or well defined erythema (grade 1 or 2) was noted in all animals from day 1 to day 3, 4 or 5.

Mean scores calculated for each animal over 24, 48 and 72 hours were as follows:

.erythema: 0.7, 1.0, 1.3; showing no significant inflammation,

.edema: 0.0, 0.0, 0.0; showing no significant inflammation.

 

Conclusion

Under the experimental conditions of this study, the test item, Glycerol formal, was slightly irritant when applied topically to rabbits.

However, the test item is not classified as irritating to skin