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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:
March 2016 - April 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
2015
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Version / remarks:
2008
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 870.2500 (Acute Dermal Irritation)
Version / remarks:
1998
Deviations:
no
Qualifier:
according to
Guideline:
other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000, including the most recent partial revisions.
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Date certificate 3 November 2015

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
- Name of test material (as cited in study report): Diamine methylated
- Substance type:Amber liquid
- Physical state:Liquid
- Storage conditions of test material:At room temperature
- Content (certified): 100% (UVCB–Substance)
- Batch/Lot number:211401A Morris
- Expiration date of the lot/batch:24 March 2018

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
- Source: Charles River France, L’Arbresle, France.
- Age at study initiation: At start of dosing, the animals were 14 and 13 weeks
- Body weight at study initiation: 2362 and 2715 gram.
- Housing: Animals were housed individually in cages with perforated floors and shelters.
- Diet: Free access to pelleted diet for rabbits (Global Diet 2030 from Harlan Teklad, Italy). Hay and wooden sticks were available during the study period.
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
set to maintain:
- Temperature (°C): 18 – 24
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 05 April 2016 to 21 April 2016

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Controls:
other: Adjacent areas of the untreated skin of each animal served as controls.
Amount / concentration applied:
TEST MATERIAL
- Amount applied: 0.5 mL
Duration of treatment / exposure:
Single application.
Observation period:
24 hours
Number of animals:
3 males.
Details on study design:
STUDY DESIGN
The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). After considering the degree of skin reactions observed in the first animal, the study was extended with the treatment of one additional animal in a stepwise exposure regime to derive the appropriate classification.

TEST SUBSTANCE PREPARATION
The test item was applied undiluted as delivered by the Sponsor.

TEST SITE
Approximately 24 hours before treatment, the dorsal fur was clipped with electric clippers, exposing an area of approximately 150 square centimeters (10x15 cm). The test substance was applied to the skin of one flank, using a metalline patch of 2x3 cm.

The second animal of the study was treated similarly to the first animal but with two patches in a stepwise exposure regime. The first patch was removed 3 minutes after application. Since no signs of severe skin reactions (i.e. necrosis or corrosion) were observed after 3 minutes and it was considered that exposure can be continued humanely, one patch was applied to a separate skin-site on the intact, clipped skin of this animal, using an identical procedure. The dressing was removed after 1 hour exposure.

REMOVAL OF TEST SUBSTANCE
Four hours after the application, the dressing was removed and the skin cleaned of residual test substance using tap water.

OBSERVATIONS
- Mortality/Viability: Twice daily.
- Toxicity: At least once daily.
- Body Weight: Day of treatment (prior to application) and on the day of the last observation.
- Irritation:
In the initially treated animal, the skin reactions were assessed at approximately 1 and 24 hours after the removal of the dressing and test item. In the second animal, the treated sites were assessed immediately after removal of a dressing and approximately 3, 4 and 24 hours after the removal of the last dressing and test item. The irritation scores and a description of all other (local) effects were recorded. Adjacent areas of the untreated skin served as controls.
- Histopathology:
Histological examination of the treated skin was performed. The animals were sacrificed for humane reasons immediately after the 24-hour observation and the skin samples of the animals (only 3-minutes sample of second animal) were fixed in 10% buffered formalin (neutral phosphate buffered 4% formaldehyde solution). The 3-minutes skin sample of the second animal was prepared for microscopy. To further investigate the skin lesions, microscopic examination of routinely prepared hematoxylin-eosin stained paraffin section of the skin sample was performed.

SCORING SYSTEM:
The irritation was assessed according to the numerical scoring system according to OECD 404.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24 h
Score:
4
Max. score:
4
Reversibility:
other: Due to severe effects the animal was sacrificed for humane reasons after the 24 hours reading.
Irritation parameter:
edema score
Basis:
animal #1
Time point:
24 h
Remarks on result:
not determinable
Remarks:
Scoring for oedema at 24 hours after exposure was not possible due to the scabs and grey discoloration of the skin
Irritation parameter:
erythema score
Basis:
animal #2
Remarks:
3-minute patch
Time point:
24 h
Score:
4
Max. score:
4
Reversibility:
other: Due to severe effects the animal was sacrificed for humane reasons after the 24 hours reading.
Irritation parameter:
edema score
Basis:
animal #2
Remarks:
3-minute patch
Remarks on result:
not determinable
Remarks:
Scoring for oedema at 24 hours after exposure was not possible due to the scabs and grey discoloration of the skin
Irritation parameter:
erythema score
Basis:
animal #2
Remarks:
1-hour patch
Time point:
24 h
Score:
4
Max. score:
4
Reversibility:
other: Due to severe effects the animal was sacrificed for humane reasons after the 24 hours reading.
Irritation parameter:
edema score
Basis:
animal #2
Remarks:
1-hour patch
Time point:
24 h
Remarks on result:
not determinable
Remarks:
Scoring for oedema at 24 hours after exposure was not possible due to the scabs and grey discoloration of the skin
Irritant / corrosive response data:
Four hours exposure to 0.5 mL of Diamine methylated resulted in very severe skin reactions in the treated skin area of the first animal. Well-defined erythema (grade 2) and moderate oedema (grade 3) were noted at one hour after exposure. At 24 hours after application severe erythema (grade 4) and scab formation were scored. Moreover, grey discolouration of the skin, a sign of necrosis was noted. The affected skin area was approximately 4 x 4 centimetres which is larger than the application area (2 x 3 cm). Scoring for oedema at 24 hours after exposure was not possible due to the scabs and necrosis of the skin. Due to these severe effects the animal was sacrificed for humane reasons after the 24 hours reading.

To derive the appropriate classification the study was extended with the treatment of one additional animal in a stepwise exposure regime. 3-minutes exposure resulted in very slight erythema (grade 1) but no oedema. Since no signs of severe skin reactions were observed immediately after 3 minutes exposure, one patch was applied to a separate skin-site which was removed after 1 hour exposure. 1-hour exposure to Diamine methylated resulted in very slight erythema (grade 1) and moderate oedema (grade 3) immediately after exposure. The skin reactions following both exposure durations worsened during the first day, resulting in moderate to severe erythema (grades 2 and 3, respectively) and severe oedema (grade 4). At 24 hours after application severe erythema (grade 4) and scab formation were scored and grey discolouration of the skin, a sign of necrosis was noted at both locations. The affected skin area was approximately 4 x 4 centimetres (larger than the application area of 2 x 3 cm). Scoring for oedema at 24 hours after exposure was not possible due to the scabs and necrosis of the skin. Due to these severe effects the animal was sacrificed for humane reasons after the 24 hours reading.
Other effects:
Microscopic skin lesions consisted of marked epidermal necrosis with marked mixed inflammatory infiltrate (heterophilic, macrophages) with epidermal and dermal cell debris.

No signs of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Conclusions:
A primary skin irritation/corrosion study with Diamine methylated in rabbits, was performed according to OECD/EC test guidelines. 24-Hours after exposure of 3-minutes, evidence of full thickness destruction of the skin was observed during the observation period and after microscopic examination, indicating that corrosion of the skin had occurred following 3-minute dermal application of Diamine methylated to the intact rabbit skin. Based on the severity of the skin reactions Diamine methylated should be classified as Skin Corrosive (Category 1B).
Executive summary:

A primary skin irritation/corrosion study with Diamine methylated in rabbits, was performed according to OECD/EC test guidelines and in accordance with GLP principles.

Initially, one rabbit was exposed to 0.5 mL of Diamine methylated, by application onto clipped skin for 4 hours using a semi-occlusive dressing. Well-defined erythema (grade 2) and moderate oedema (grade 3) were noted at one hour after exposure. At 24 hours after application severe erythema (grade 4) and scab formation were scored. Moreover, grey discolouration of the skin, a sign of necrosis, was noted. The affected skin area was approximately 4 x 4 centimetres which is larger than the application area (2 x 3 cm). Scoring for oedema at 24 hours after exposure was not possible due to the scabs and necrosis of the skin. Due to these severe effects the animal was sacrificed for humane reasons after the 24 hours reading.

To derive the appropriate classification the study was extended with the treatment of one additional animal in a stepwise exposure regime. 3-minutes exposure resulted in very slight erythema (grade 1) but no oedema. Since no signs of severe skin reactions were observed immediately after 3 minutes exposure, one patch was applied to a separate skin-site which was removed after 1 hour exposure.

1-hour exposure to Diamine methylated resulted in very slight erythema (grade 1) and moderate oedema (grade 3) immediately after exposure. The skin reactions following both exposure durations worsened during the first day, resulting in moderate to severe erythema (grades 2 and 3, respectively) and severe oedema (grade 4). At 24 hours after application severe erythema (grade 4) and scab formation were scored and grey discolouration of the skin, a sign of necrosis was noted on both exposure sites. The affected skin area was approximately 4 x 4 centimetres (larger than the application area of 2 x 3 cm). Scoring for oedema at 24 hours after exposure was not possible due to the scabs and necrosis of the skin. Due to these severe effects the animal was sacrificed for humane reasons after the 24 hours reading.

Microscopic skin lesions consisted of marked epidermal necrosis with marked mixed inflammatory infiltrate (heterophilic, macrophages) with epidermal and dermal cell debris.

Conclusion

24-hours after exposure of 3-minutes, evidence of full thickness destruction of the skin was observed during the observation period and microscopic examination, indicating that corrosion of the skin had occurred following 3-minute dermal application of Diamine methylated to the intact rabbit skin.

Based on the severity of the skin reactions:

- according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments), Diamine methylated should be classified as: Skin Corrosive (Category 1B).

- according to the Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments), Diamine methylated should be classified as: Corrosive (Category 1B) and labeled as H314: Causes severe skin burns and eye damage.