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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
November 1980
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study, acceptable for assessment, sufficiently documented.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980

Materials and methods

Test guidelineopen allclose all
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
(more severe exposure conditions: prolonged skin contact of 24 hrs, occlusive dressing, treatment of intact and scarified skin, scoring of skin lesions at 24 and 72 hrs)
Qualifier:
according to
Guideline:
other: Consumer Product Safety Commission of the USA, Code of Federal Regulations, Title 16, Section 1500.41
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Product No. 114.746
- Physical state: clear liquid
- Storage condition of test material: 20 °C in closed container

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: J. Scheele, Büderich/Westfalen, 4760 Werl, Germany
- Age at study initiation: no data
- Weight at study initiation: no data
- Housing: single
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +- 1 °C
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
occlusive
Preparation of test site:
other: shaved, or shaved and scarified
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 mL
Duration of treatment / exposure:
24 hrs
Observation period:
24 and 72 hrs after start of exposure
Number of animals:
6
Details on study design:
TEST SITE
- Application: The test substance was dispensed on 2.5 x 2.5 cm2 patches which were then applied to the prepared skin areas
and fixed by elastoplast; patches were removed after 24 hrs of skin contact.
- Area of exposure: 2.5 x 2.5 cm2
- Type of wrap if used: unpermeable material as e.g. a rubber cloth

SCORING SYSTEM: according to Draize, comparable to OECD Guideline 404 (for details see Table 1)
Calculation of primary dermal irritation index:
sum of the scores of each animal for [(Erythema and eschar formation) + (Oedema formation) from intact skin] + [(Erythema and eschar formation) + (Oedema formation) from scarified skin] divided by 24; maximal achievable value is 8.0.
For criteria for classification see Table 2

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24 hrs
Score:
0.63
Reversibility:
fully reversible within: 48 hrs after termination of application
Remarks on result:
other: includes reactions both for intact and abraded skin
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24 and 72 hrs
Score:
0.5
Reversibility:
fully reversible within: 48 hrs after termination of application
Remarks on result:
other: reaction for intact sklin
Irritant / corrosive response data:
see Table 3

Any other information on results incl. tables

Table 3: Overview on skin reactions after single occlusive application of acetophenone for 24 hrs (scores at the end of the exposure period)

 Rabbit No.  Erythema score     Edema score   
   intact skin  scarified skin  intact skin  scarified skin
 1  1  1  1  1
 2  1  1  1  1
 3  0  0  1  1
 4  0  0  1  1
 5 0  2  0  1
 6  0  0  0  0

All changes were fully reversible within the following 48 hrs: all scores were 0.

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
With a primary irritation index of 0.5 after a 24-hr contact with intact skin, the classification would be "not irritating" according to the ETAD criteria.
No classification according to EU criteria is expected as mean irritation scores for erythema or edema were significantly below the critical value of 2.0 even under the conditions of this test with a prolonged contact time of 24 hrs instead of 4 hrs.
Executive summary:

Skin irritation scores according to Draize were assessed on skin sites of six rabbits (both shaved intact skin or shaved scarified skin) following a 24-hr occlusive application of 0.5 mL acetophenone on a patch. Except for the prolonged skin contact the testing procedure was comparable to OECD Guideline 404. Findings at the end of exposure on intact skin were very slight erythema in 2/6 rabbits and very slight oedema in 4/6 rabbits. Abraded skin sites showed very slight erythema in 2/6 and slight erythema in 1/6, and very slight oedema in 5/6 rabbits. All effects were fully reversible within the following 48 hrs. With a primary irritation index (PII) of 0.63 after a 24-hr skin contact, acetophenone was assessed as slightly irritating to rabbit skin according to ETAD criteria (PII of 0.6 -3.0) when the reactions of both intact and scarified skin were considered. With a PII of 0.5 for intact skin acetophenon is non irritating.

No classification according to EU criteria is expected as mean irritation scores for erythema or edema with maximal scores of 1.0 for intact skin were significantly below the critical value of 2.0 even under the conditions of this test with a prolonged contact time of 24 hrs instead of 4 hrs.