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Toxicological information

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:
from 2006-06-14 to 2006-07-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline-conform study performed under GLP without deviations

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
1994

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): beta carotene, technical grade
- Physical state: dark red crystals
- Analytical purity: 97.77%
- Purity test date: 4 May 2005
- Lot/batch No.: WC00504271
- Expiration date of the lot/batch: July 2007
- Stability under test conditions: stable under storage conditions
- Storage condition of test material: at room temperature (20 °C ± 5 °C), protected from humidity and light. Storage under inert gas (nitrogen)

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Netherlands BV, Horst, The Netherlands
- Age at study initiation: male: 13-14 weeks, female 8-9 weeks
- Weight at study initiation: 1460 - 2418 g
- Housing: Individually in stainless steel cages, equipped with feed hoppers and drinking water bowls. Wood blocks and haysticks were provided for gnawing.
- Diet (e.g. ad libitum): Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum (batch no. 8/06) provided by Provimi Kliba AG, Kaiseraugst.
- Water (e.g. ad libitum): Community tap water from Füllinsdorf, ad libitum.
- Acclimation period: yes, under laboratory conditions after health examinations. Only animals without any visible signs of illness were used for the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23 °C
- Humidity (%): 30-70 %
- Air changes (per hr): 10-15 changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours light, 12 hours dark (automatically controlled light cycle, with music played during the daytime)

Test system

Type of coverage:
semiocclusive
Preparation of test site:
other: clipped
Vehicle:
water
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g per animal moistened with purified water

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 mL of water was used to moisten the substance
Duration of treatment / exposure:
4 hours
Observation period:
VIABILITY/MORTALITY
Daily from acclimatisation of the animals to the termination of the test

CLINICAL SIGNS
Daily from acclimatisation of the animals to the termination of the test

BODYWEIGHTS
At start of acclimatisation, on the day of application and at termination of observation

SKIN OBSREVATION
The skin reaction was assessed at approximately 1, 24, 48 and 72 hours, as well as 7, 10 and 14 days after exposure (removal of the dressing, gauze patch and test item)
Number of animals:
3 animals (1 male, 2 female)
Details on study design:
TEST SITE
- Area of exposure: left flank
- % coverage: not reported, 4 cm x 4 cm
- Type of wrap if used: surgical gauze

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the 4 hour treatment, the dressing was removed and the skin was flushed with lukewarm tap water to clean the application site
- Time after start of exposure: 4 hours

SCORING SYSTEM:
The skin reaction was assessed according to the numerical scoring system listed in the Commission Directive 2004/73/EC, April 29, 2004. If evident, corrosive or straining properties of the test item were described and recorded.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Reversibility:
other: not applicable
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Reversibility:
other: not applicable
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.33
Reversibility:
fully reversible
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
0
Reversibility:
other: not applicable
Irritation parameter:
edema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0
Reversibility:
other: not applicable
Irritation parameter:
edema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0
Reversibility:
other: not applicable
Irritant / corrosive response data:
The mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for oedema grades, separately. The mean erythema/eschar score of the three animals was 0.00, 0.00 and 0.33 respectively and the mean oedema score was 0.00 for all the animals. Very slight erythema forming was observed in all animals, one hour after removal of the dressing and persisted in one female animal until the 24 hour reading.
Neither alterations of the treated skin were observed, nor were corrosive effects evident on the skin.
Other effects:
No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred. Slight red staining of the treated skin area produced by the test item was present in all animals from the 1 hour to the 7 day reading and persisted in one female animal until the 10-day reading. No abnormal findings were observed on the treated skin of animals 14 days after treatment, the end of the observation time. The body weights of all rabbits were considered to be within the normal range of variability.

Any other information on results incl. tables

Table 1: Bodyweights

Animal No.

Sex

First day of acclimatisation

Day of treatment

Last day of observation

31

Male

2130

2418

2841

32

Female

1304

1407

1936

33

Female

1249

1460

1864

Table 2: Skin irritation scores (individual values)

Animal number

Sex

Evaluation interval*

Erythema

Oedema

31

32

33

M

F

F

1 hour

1

1

1

0

0

0

31

32

33

M

F

F

24 hours

0

0

1

0

0

0

31

32

33

M

F

F

48 hours

0

0

0

0

0

0

31

32

33

M

F

F

72 hours

0

0

0

0

0

0

31

32

33

M

F

F

7 days

0

0

0

0

0

0

31

32

33

M

F

F

10 days

0

0

0

0

0

0

31

32

33

M

F

F

14 days

0

0

0

0

0

0

* examinations were performed at the specified times after removal of the dressing.

Note: observations continued for 14 days due to staining present on the skin

Table 3: Skin irritation scores (Individual mean values after 24, 48 and 72 hours)

Animal number

Sex

Erythema

N

Oedema

N

31

32

33

M

F

F

0.00

0.00

0.33

3

3

3

0.00

0.00

0.00

3

3

3

N = number of available data points

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based on the referred classification criteria (Commission Directive 2001/59/EC of August 2001), the test item is considered to be "not irritating" to rabbit skin.
Executive summary:

The primary skin irritation potential of the test item was investigated under GLP according to OECD TG 404. The test item was applied by topical semi-occlusive application of 0.5 g substance moistened with 0.5 mL of water to the intact left flank of each of three young adult New Zealand White rabbits. The duration of treatment under occlusion was four hours. The scoring of skin reactions was performed 1, 24, 48 and 72 hours, as well as 7, 10 and 14 days after removal of the dressing.

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for oedema grades separately. The mean erythema/eschar score of the three animals was 0.00, 0.00 and 0.33 respectively and the mean oedema score was 0.00 for all the animals.

The application of the test item to the skin resulted in very slight erythema in all animals 1 hour after removal of the dressing, persisting in one female animal until the 24 -hour reading. Red staining of the treated skin area produced by the test item was noted in all animals from the 1-hour reading to the 7-day reading and persisted in one female animal until the 10-day reading. No corrosive effects were noted on the treated skin of any animal at any of the measuring intervals and no clinical signs were observed. Thus, the test item did not induce significant or irreversible damage to the skin.

Based on the referred classification criteria (Commission Directive 2001/59/EC of August 2001), the test item is considered to be "not irritating" to rabbit skin.