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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 26 March 2013 to 15 May 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the OECD Guideline and EU Method in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

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
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): C12-14 alkylmorpholine
- Analytical purity: 98.3%:
- Lot/batch No.: S-001312
- Expiration date of the lot/batch: 05 December 2017
- Storage condition of test material: Room temperature in the dark

Test animals

Species:
rabbit
Strain:
other: New Zealand White (Hsdlf:NZW)
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Leicestershire, UK
- Age at study initiation: 12-20 weeks old
- Weight at study initiation: 2.63 to 2.85 kg
- Housing: The animals were individually housed in suspended cages.
- Diet: 2930C Teklad global rabbit diet supplied by Harlan Laboratories UK Ltd., Oxon UK (ad libitum)
- Water: Free access to mains drinking water
- Acclimation period: 5 d

ENVIRONMENTAL CONDITIONS
- Temperature: 17 to 23 °C
- Humidity: 30 to 70%
- Air changes: 15 changes/h
- Photoperiod: The lighting was controlled by a time switch to give 12 h continuous light (06:00 to 18:00) and 12 h darkness

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 mL
Duration of treatment / exposure:
3-minute, 1 and 4 h
Observation period:
14 d
Number of animals:
3
Details on study design:
TEST SITE
On the day before the test each of a group of three rabbits was clipped free of fur from the dorsal/flank area using veterinary clippers. Only animals with a healthy intact epidermis by gross observation were selected for the study. One rabbit was initially treated. Three suitable sites were selected on the back of the rabbit. A quantity of 0.5 mL of the test substance was applied directly to the skin under a 2.5 cm x 2.5 cm cotton gauze patch. Each patch was secured in position with a strip of surgical adhesive tape. To prevent the animal interfering with the patches, the trunk of the rabbit was wrapped in an elasticated corset for the duration of the exposure period.

REMOVAL OF TEST SUBSTANCE
One patch was removed at each of three time points: 3 minutes, 1 h and 4 h after application. Any residual test substance was removed by gentle swabbing with cotton wool soaked in distilled water.

SCORING SYSTEM: Draize

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
other: 24, 48 and 72 h
Score:
0.66
Max. score:
4
Reversibility:
fully reversible within: 14 d
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
other: 24, 48 and 72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 14 d
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
other: 24, 48 and 72 h
Score:
2
Max. score:
4
Reversibility:
not fully reversible within: 14 d
Irritation parameter:
edema score
Basis:
animal #1
Time point:
other: 24, 48 and 72 h
Score:
0.33
Max. score:
4
Reversibility:
fully reversible within: 7 d
Irritation parameter:
edema score
Basis:
animal #2
Time point:
other: 24, 48 and 72 h
Score:
1
Max. score:
4
Reversibility:
fully reversible within: 14 d
Irritation parameter:
edema score
Basis:
animal #3
Time point:
other: 24, 48 and 72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 14 d
Irritation parameter:
primary dermal irritation index (PDII)
Basis:
mean
Time point:
other: 24, 48 and 72 h
Score:
2.8
Max. score:
8
Reversibility:
fully reversible within: 14 d
Irritant / corrosive response data:
3-minute exposure period: Moderate desquamation was noted at the treated skin site at the Day 7 observation. No other evidence of skin irritation was noted during the study. The treated skin site appeared normal at the 14 d observation.
1-h exposure period: Well-defined erythema and very slight edema were noted at the treated skin site at the 72 h observation. Very slight erythema and moderate desquamation were noted at the treated skin site at the 7 d observation. The treated skin site appeared normal at the 14-d observation.
4-h exposure period: Very slight erythema and very slight or slight edema was noted at two treated skin sites immediately after patch removal. Very slight or well-defined erythema and very slight or slight edema were noted at these two treated skin sites one hour after patch removal with well-defined erythema and very slight or slight edema noted at the 24 and 48-h observations. Well-defined erythema and very slight or slight edema were noted at all treated skin sites at the 72 h observations. Well-defined erythema and very slight edema were noted at one treated skin site with very slight erythema, with or without very slight edema, noted at the other two treated skin sites at the 7 d observation. The erythema extended approx 2 cm beyond two treated skin sites at the 24, 48 and 72 h observations and at one of these treated skin sites at the 7 d observation. Edema extended ventrally below one treated skin site at the 24, 48 and 72 h observations. Loss of skin elasticity was noted at one treated skin site at the 48 and 72 h observations. Moderate desquamation was noted at all treated skin sites with superficial cracking of the epidermis also noted at one treated skin site at the 7 d observation. Glossy skin was noted at two treated skin sites at the 7 and 14 d observations. Reduced regrowth of fur was also noted at these two treated skin sites at the 14 d observation.
Other effects:
All animals showed expected gain in body weight during the study.

Any other information on results incl. tables

TABLES:

Table 1: Individual skin reactions following 3 -minute and 1-h exposures:

Skin Reaction

Observation time (following patch removal)

Individual Scores -Rabbit number and sex

73069 Male

 

3 -minute exposure

1 -h exposure

 

Immediately

0

0

 

1 h

0

0

 

24 h

0

0

Erythema/Eschar Formation

48 h

0

0

 

72 h

0

2

 

7 d

0D

1D

 

14 d

0

0

 

Immediately

0

0

 

1 h

0

0

 

24 h

0

0

Edema Formation

48 h

0

0

 

72 h

0

1

 

7 d

0

0

 

14 d

0

0

D = Moderate desquamation,

Table 2. Individual skin reactions following 4-h exposure:

Skin reaction

Observation time (following patch removal)

Individual scores – Rabbit number and sex

Total

73069 Male

73110 Male

73160 Male

Erythema/Eschar Formation

Immediately

0

1

1

( 2 )

1 h

0

1

2

( 3 )

24 h

0

2R

2R

4

48 h

0

2R

2RLe

( 4 )

72 h

2

2R

2RLe

6

7 d

1D

1DG

2RDGCr

( 4 )

14 d

0

0GFr

0GFr

( 0 )

Edema Formation

Immediately

0

1

2

( 3 )

1 h

0

1

2

( 3 )

24 h

0

1

2Oe

3

48 h

0

1

2Oe

( 3 )

72 h

1

1

2Oe

4

7 d

0

1

1

( 2 )

14 d

0

0

0

( 0 )

Sum of 24 and 72-h readings (S) : 17

 

Primary Irritation Index (S/6) : 17/6 = 2.8

 

Classification : MODERATE IRRITANT

 

( ) = Total values not used for calculation of primary irritation index

D = Moderate desquamation

Le = Loss of skin elasticity

G = Glossy skin

Cr = Superficial cracking of the epidermis

Fr = Reduced regrowth of fur

R = Reaction extends approximately 2 cm beyond treatment site

Oe = Edema extends ventrally below treatment site

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant)
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the study conditions, the test substance produced moderate skin irritation in rabbits.
Executive summary:

The study was performed to assess the irritancy potential of C12-14 alkylmorpholine following single, 3-minute, 1 and 4-h, semi-occluded applications to the intact rabbit skin according to the OECD Guideline 404 and EU Method B.4 in compliance with GLP.

0.5 mL of the test substance was applied directly to the skin under a 2.5 cm x 2.5 cm cotton gauze patch.

3-minute and 1 h semi-occluded applications of the test substance to the intact skin of one rabbit produced no corrosive effects. A single 4-h, semi occluded application of the test substance to the intact skin of three rabbits produced well-defined erythema and very slight to slight edema. Other skin reactions noted were moderate desquamation, loss of skin elasticity, glossy skin, superficial cracking of the epidermis, reduced regrowth of fur and reactions extending beyond the treatment site. No corrosive effects were noted.

Under the study conditions, the test substance produced moderate skin irritation with a primary irritation index of 2.8.

The average of the reactions at 24, 48 and 72 hrs were below 2.3 for oedema and erythema/eschar formation for all three animals, and the scoring at the end of the 14-day observation was 0 for all animals. However, considering observations as moderate desquamation in all three animals, and the involvement of reactions extending beyond treatment site, loss of skin elasticity, superficial cracking of the epidermis in two animals resulting to glossy skin and reduced regrowth of fur still observed at the end of the 14-day observation period, classification for Cat.2 skin irritation seems justified.