Registration Dossier

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20/07/1982-23/07/1982
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline studies with acceptable restrictions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report Date:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
yes
Remarks:
: occlusive instead of semi-occlusive dressing, scoring after 4 instead of 1h after application.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material : tert.Butyl-4-methoxy-4' dibenzoylmethane
- Physical state: liquid
- Stability under test conditions: no changes noted during storage
- Storage condition of test material: room temperature

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Animal Farm of Hoffmann-La Roche at Füllinsdorf, Basel-Land, Switzerland
- Weight at study initiation: greater than 2 kg
- Housing: singly in restrainers during first 6 hours of the test, thereafter in stainless cages
- Diet (e.g. ad libitum): ad libitum (except on the day of administration)
- Water (e.g. ad libitum): tap water ad libitum (except on the day of administration)
- Acclimation period: Minimum of seven days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 0.5°C
- Humidity (%): 65± 5%
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:
occlusive
Preparation of test site:
abraded
Vehicle:
unchanged (no vehicle)
Controls:
yes, concurrent vehicle
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): 10% in ethanol/2-phenylethanol (50/50) (CAS 60-12-8)

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 mL
Duration of treatment / exposure:
exposure time: 4 or 24h
Observation period:
up to 72h after treatment
Number of animals:
Butyl methoxydibenzoylmethane (BMDBM): 6 animals
Vehicle control: 6 animals
Details on study design:
TEST SITE
- Area of exposure: back of the rabbits; left side: abraded skin, right side: intact skin
- coverage: 2x2 cm gauze patch
- Type of wrap if used: occlusive dressing by plastic foil, held in place by elastic network

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: 4 and 24h

SCORING SYSTEM: see Table 1).

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 24h
Score:
0.83
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: intact skin
Irritation parameter:
edema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 24h
Score:
0.17
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: intact skin
Irritation parameter:
erythema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 48h
Score:
0.5
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: intact skin
Irritation parameter:
edema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 48h
Score:
0.17
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: intact skin
Irritation parameter:
erythema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 24h
Score:
1.33
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: abraded skin
Irritation parameter:
edema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 24h
Score:
1
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: abraded skin
Irritation parameter:
erythema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 48h
Score:
1.17
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: abraded skin
Irritation parameter:
edema score
Basis:
mean
Remarks:
of 6 animals
Time point:
other: 48h
Score:
0.5
Max. score:
4
Reversibility:
other: see Table 2
Remarks on result:
other: abraded skin
Irritant / corrosive response data:
After 4h application of BMDBM (as 10% solution in ethanol/2-phenylethanole 50/50) to intact or abraded rabbit skin, no to well-defined erythema were observed, resulting in a mean score of 0.67 and 1.17 for intact and abraded skin, respectively. Edemas were less pronounced, showing no to very slight response with mean values of 0.11 and 0.83 for intact and abraded skin, respectively.
When testing the solvent solely, the mean irritation scores for erythema formation were 0.56 and 1.00 for intact and abraded skin, respectively. The edema scores were 0.00 and 0.78 for intact and abraded skin, respectively.
These results indicate that the substance tested possesses a slight irritating potential which is mainly caused by the solvent used.

Any other information on results incl. tables

 Table 2: Primary irritation index after 4h exposure of 10% BMDBM in ethanol/2-phenylethanol (50/50) to intact and abraded skin:

Rabbit No.

Erythema score

Edema score

4h

24h

48h

4h

24h

48h

Intact skin

1

0

0

0

0

0

0

2

1

0

0

0

0

0

3

1

2

1

0

0

0

4

0

2

2

0

1

1

5

1

1

0

0

0

0

6

1

0

0

0

0

0

Mean:

0.67

0.83

0.5

0

0.17

0.17

Abraded skin

1

1

1

1

1

1

1

2

1

1

1

1

1

0

3

1

2

1

1

1

1

4

1

2

2

1

1

1

5

1

1

1

1

1

0

6

1

1

1

1

1

0

Mean:

1

1.33

1.17

1

1

0.5

 

 

Table 3: Primary irritation index after 4h exposure of the vehicle (ethanol/2-phenylethanol (50/50)) to intact and abraded skin:

Rabbit No.

Erythema score

Edema score

4h

24h

48h

4h

24h

48h

Intact skin

1

1

1

1

0

0

0

2

1

0

0

0

0

0

3

1

0

0

0

0

0

4

1

1

0

0

0

0

5

1

1

0

0

0

0

6

1

0

0

0

0

0

Mean:

1

0.5

0.17

0

0

0

Abraded skin

1

1

1

1

1

1

1

2

1

1

1

1

1

0

3

1

1

0

1

1

0

4

1

2

1

1

1

1

5

1

1

1

1

1

0

6

1

1

1

1

1

0

Mean:

1

1.17

0.83

1

1

0.33

 

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: OECD GHS
Conclusions:
Occlusive application of 10% butyl methoxydibenzoylmethane (BMDBM) in ethanol/2-phenylethanol for 4h to intact or abraded rabbit skin caused no to slight erythema and edema. Also the vehicle ethanol/2-phenylethanol (50/50) causes these effects but in a somewhat lower potency.
Executive summary:

After occlusive application of 0.5mL of the test item (10% BMDBM solved in ethanol/2-phenylethanol (50/50)) for 4 hours to intact or abraded rabbit skin, no to moderate formation of erythema and no to very slight edema formation was noted. The mean scores (erythema/edema) were 0.83/0.17 on intact skin and 1.33/1.00 on abraded skin 24h after application. Testing the solvent caused no to very slight erythema and edema resulting in scores (erythema/edema) of 0.50/0.00 on intact skin and 1.17/1.00 on abraded skin 24h after application. It can therefore be concluded that the skin irritations are mainly due to the vehicle used and that BMDBM bears very slight irritating potential.

As the erythema/edema score is <2.3 in all animals no classification as skin irritant according to OECD GHS is needed