4-amino-2-methylquinoline

Endpoint summary

Description of key information

Skin irritation/corrosion: Key study: Test method according to OECD Guideline 430. GLP study. The test item does not lead to skin corrosion/severe irritation. 
Eye irritation: Key study: Test method according to OECD Guideline 438. GLP study. On the grounds of the study results it may be stated that the test item may lead to corneal damage. According to the GHS the test item can be classified into Category 1.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 11 to June 22, 2015.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test method according to OECD Guideline 430, EU Method B.40 and GLP study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 430 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test Method (TER))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Centre for Experimental Medicine (Medical University in Katowice).
- Age at study initiation: 20 days old.
- Housing: Plastic cage covered with a wire bar lid, of 58 x 37 x 21 cm. UV-sterilised wood shavings were used as bedding.
- Diet (e.g. ad libitum): Murigran (batch number 3/15) standard granulated laboratory fodder ad libitum.
- Water (e.g. ad libitum): Tap water ad libitum.
- Acclimation period: 3 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 ºC.
- Humidity (%): 44-89 %.
- Air changes (per hr): about 16 times/hour.
- Photoperiod (hrs dark / hrs light): 12 hours/12h light.

Type of coverage:

other:

Preparation of test site:

shaved

Vehicle:

water

Remarks:

distilled water

Controls:

yes

Amount / concentration applied:

VEHICLE
- Amount(s) applied (volume or weight with unit): Distilled water (150 μL).

Duration of treatment / exposure:

24 h

Number of animals:

2

Details on study design:

TEST SITE
- Area of exposure: The skin disc were removed from the dorsal and flank areas.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The test item and the control items were removed by washing with a jet of tap water at up to 30ºC.
- Time after start of exposure: 24h

SCORING SYSTEM:
The test item is considered to be non-corrosive to skin if:
- the mean TER value obtained for the test item is greater than 5 kΩ, or
- the mean TER value is less than or equal to 5 kΩ, and the skin disc shows no obvious damage.
The test item is considered to be corrosive to skin if:
- the mean TER value obtained for the test item is less than or equal to 5 kΩ and
- the skin disc is obviously damaged.

Irritant / corrosive response data:

The gross examination showed that the positive control skin discs exhibited skin perforation, whereas the negative control skin discs and the ones treated with the test item did not reveal any changes.

Table 1. Results of the transcutaneous electrical resistance test (TER).

Animal number	Tested substance	Skin disc number	TER value(kΩ)	Mean TER value± SD (kΩ)
1	Positive control – 36 % HCl	1	0.89	0.89 ± 0.01
		2	0.90
		3	0.89
	Negative control – distilled water	1	19.68	19.56 ± 0.27
		2	19.25
		3	19.75
	Test item	1	5.68	5.91 ± 0.29
		2	5.81
		3	6.23
2	Positive control – 36% HCl	1	0.90	0.90 ± 0.01
		2	0.91
		3	0.90
	Negative control – distilled water	1	16.58	16.91 ± 0.31
		2	17.20
		3	16.95
	Test item	1	6.68	6.81 ± 0.18
		2	6.73
		3	7.01

Table 2. Gross changes on the surface of the treated skin discs.

Animal number	Tested substance	Skin disc number	Gross changes
1	Positive control – 36% HCl	1	Perforation
		2	Perforation
		3	Perforation
	Negative control – distilled water	1	No changes
		2	No changes
		3	No changes
	Test item	1	No changes
		2	No changes
		3	No changes
2	Positive control – 36% HCl	1	Perforation
		2	Perforation
		3	Perforation
	Negative control – distilled water	1	No changes
		2	No changes
		3	No changes
	Test item	1	No changes
		2	No changes
		3	No changes

The gross examination showed that the positive control skin discs exhibited skin perforation, whereas the negative control skin discs and the ones treated with the test item did not reveal any changes.

 

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item did not induce skin corrosion/severe irritation effects in this in vitro TER skin corrosion test.

Executive summary:

The in vitro skin corrosion test (transcutaneous electrical resistance), was performed according to OECD Guideline 430, EU method B.40 and followed GLP principles. The skin discs used in the experiment were obtained from 2 young female Wistar rats (28 -day-old animals). The electrical resistance of the skin discs measured before the start of the experiment was greater 10 kΩ. Three skin discs obtained from each animal were used for the test item and three for each control item. The test item was applied to the epidermal surface of the skin placed in a tube for 24h. Positive (36% hydrochloric acid) and negative (distilled water) controls were conducted concurrently. After removing the test item (or control item), the surface tension of the skin was reduced with a solution of ethanol, and after that a solution of MgSO₄ was applied to hydrate the skin. Then the electrical resistance of the skin was measured placing the databridge electrodes on either side of the skin disc. The mean TER results were 5.91 and 6.81 kΩ (both higher than 5 kΩ). After that, the MgSO₄ solution was removed and gross examination of the skin did not detect visible changes. In conclusion, the test item was not considered to lead to skin corrosion/severe irritation under the test conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From May 11 to June 22, 2015.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test method according to OECD guideline 438, EU Method B.48 and GLP study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying Ocular Corrosives and Severe Irritants)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU method B.48 (Isolated chicken eye test method for identifying occular corrosives and severe irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

other: chicken

Strain:

not specified

Details on test animals or tissues and environmental conditions:

TEST ANIMALS:
- Source: Zakład Przemysłu Drobiarskiego JAS-DROP in Krzyżowice.
- Age at study initiation: 7 weeks old.
- Weight at study initiation: from 1.5 to 2.5 kg

BIOLOGICAL MATERIAL
After sedation of the chickens by electric shock and incision of the neck for bleeding, their heads were transported to the laboratory in a plastic container at ambient temperature. During the transport, the heads were humidified with a physiological salt solution by placing moistered properties paper towels inside the container. The time interval between the collection of the chickens heads and the use of their eyeballs in the ICE test was 30 minutes.

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.03 g. Control: 0.03mL.

Duration of treatment / exposure:

10 seconds.
Positive control: Imidazole.
Negative control: Physiological Salt

Observation period (in vivo):

30, 75, 120, 180, and 240 minutes (± 5 minutes).

Number of animals or in vitro replicates:

3 eyeballs for group. 3 groups (1 treated and 2 controls)

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes, with 20 mL of physiological salt.
- Time after start of exposure: after the 10 seconds-exposure period.

MEASURED PARAMETERS
The corneas treated with the test item and the control items were evaluated pretreatment and starting at 30, 75, 120, 180, and 240 minutes (± 5 minutes) after the post-treatment rinse. At all observation times points, corneal opacity and swelling were evaluated, whereas morphological changes of the corneal surface were recorded. The quantitative determination of fluorescein retention was performed only once, i.e. 30 minutes after the end of the exposure.

SCORING SYSTEM:
Fluorescein retention
0 No fluorescein retention
0.5 Very minor single cell staining
1 Single cell staining scattered throughout the treated area of the cornea
2 Focal or confluent dense single cell staining
3 Confluent large areas of the cornea retaining fluorescein

Corneal opacity
0 No opacity
0.5 Very faint opacity
1 Scattered or diffuse areas; details of the iris are clearly visible
2 Easily discernible translucent areas; details of the iris are slightly obscured
3 Severe corneal opacity; no specific details of the iris are visible; size of the pupil is barely discernible
4 Complete corneal opacity; iris invisible

Corneal swelling
The degree of corneal swelling was determined by measuring corneal thickness using an SP-100 pachymeter.

Gross evaluation
The aim of this evaluation was to determine whether any morphological effects, e.g. pitting of corneal epithelial cells, roughening of the corneal surface, and sticking of the test item to the cornea were visible.

Histopathological evaluation of the treated corneas
Following the final evaluation of the treated eyeballs (240 minutes after the application of the test item and the control items), the eyeballs were fixed in a 4% solution of formaldehyde. Next, specimens were collected (one specimen in the plane including the cornea, lens, and optic nerve). The tissue material was dehydrated and prepared using a paraffin technique. Paraffin blocks were cut into smaller parts, whose thickness was 5 μm, with a microtome and stained using Hematoxylin and Eosin. The following layers of the cornea were evaluated: anterior epithelium, anterior elastic lamina (Bowman’s membrane), corneal stroma, posterior elastic lamina (Descemet’s membrane), and posterior epithelium. All treated eyeballs were subject to this evaluation.

Irritant / corrosive response data:

On the grounds of the study results described in this Report and the overall in vitro irritancy classification, it may be stated that the test item may lead to corneal damage. According to the GHS the test item can be classified into Category 1 (3x ICE class IV) so a second run of nine eyeballs was not conducted.

Table 1a. Fluorescein retention.

observation after time t (minutes)	test item			positive control imidazole			negative control physiological saline
	eyeball no.			eyeball no.			eyeball no.
	1	2	3	4	5	6	7	8	9
0	0	0	0	0	0	0	0	0	0
30	3	3	3	3	3	3	0	0	0

Table 2a. Corneal opacity.

observation after time t (minutes)	test item			positive control: imidazole			negative control: physiological saline
	eyeball no.			eyeball no.			eyeball no.
	1	2	3	4	5	6	7	8	9
0	0	0	0	0	0	0	0	0	0
30	3	3	3	4	4	4	0	0	0
75	3	3	3	4	4	4	0	0	0
120	3	3	3	4	4	4	0	0	0
180	3	3	3	4	4	4	0	0	0
240	3	3	3	4	4	4	0	0	0

Table 3. Corneal swelling (%)

observation after time t (minutes)	test item			positive control imidazole			negative control physiological saline
	eyeball no.			eyeball no.			eyeball no.
	1	2	3	4	5	6	7	8	9
0	-	-	-	-	-	-	-	-	-
30	24.7	32.2	55.1	43.3	52.9	49.8	2.0	2.7	5.1
75	86.6	52.7	58.6	66.6	61.4	75.4	0.3	2.0	4.1
120	106.2	54.7	75.0	77.5	69.8	81.9	-0.7	0.0	1.0
180	106.5	67.8	77.4	78.5	70.8	84.4	-1.7	-0.7	2.0
240	107.9	74.5	81.8	81.6	72.9	84.3	-3.0	-1.7	0.0

Table 4. Gross evaluation of the treated corneas.

observation after time t (minutes)	test item			positive control imidazole			negative control physiological saline
	eyeball no.			eyeball no.			eyeball no.
	1	2	3	4	5	6	7	8	9
30	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
75	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
120	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
180	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC
240	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	SIGNS	NC	NC	NC

NC = no changes

SIGNS = roughening of the corneal surface

Interpretation of results:

Category I

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

The overall in vitro irritancy classification indicate that 4-Aminoquinaldine may lead to corneal damage.

Executive summary:

The study was performed according to OECD Guideline 438 and EU Method B.48. GLP study. Chicken heads were collected from a slaughter house near the laboratory facility. The eyeballs were extracted and were assessed for potential damage by corneal opacity profusion and fluorescein retention at the beginning of the study. The test item and the positive control (imidazole) were applied in the amount of 0.03 g, whereas the item used in the negative control (physiologic salt) was applied in a volume of 0.03 mL, all for a 10 seconds time. Three eyeballs were used for the test item and three for each control item. The quantitative determination of fluorescein retention was performed only once, i.e. 30 minutes after the end of the exposure. The corneas treated with the test and control items were evaluated pretreatment and starting at 30, 75, 120, 180 and 240 minutes (± 5 minutes) after the post-treatment rinse. At all observation time points, corneal opacity and swelling were evaluated, whereas morphological changes of the corneal surface were recorded. At the end, the eyeballs were fixed in a 4% solution of formaldehyde to conduct histopathological examinations. The mean fluorescein retention score for the eyeballs treated with the test item was equal to 3.0 (ICE class IV). The mean corneal opacity score for the eyeballs treated with the test item was equal to 3.0 (ICE class IV). The mean corneal swelling values for the test item were from 37.3 to 88.1 (ICE class IV). The positive and negative control values fell within the acceptable ranges for the method. Gross examinations of the eyeballs treated with the test item revealed roughening of the corneal surface. Histopathology revealed cell alteration in the cornea and detachment of the anterior corneal epithelium. According to these results it may be stated that the test item may lead to corneal damage. According to the GHS the test item can be classified into Category 1, so a second run of nine eyeballs was not conducted.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion: Key study: The in vitro skin corrosion: transcutaneous electrical resistance test (TER) was performed according to the OECD Guideline 430 and EU Method B.40, following the Principles of GLP. The mean TER results for the skin discs treated with the test item were equal to 5.91 kΩ (animal no.1) and 6.81 kΩ (animal no.2). Gross examinations of the skin discs treated with the test item did not reveal any pathological changes. On the grounds of the study, it may be stated that the test item belongs to a group of substances which do not lead to skin corrosion/severe irritation. The mean TER values for the test item were higher than 5 kΩ and there were not any visible changes on the skin discs.

Eye irritation: Key study: The isolated chicken eye test (in vitro) was performed according to the OECD Guideline 428 and EU Method B.48, following the Principles of GLP.

For the treated eyeballs, the mean fluorescein retention score was equal to 3.0 (ICE class IV). On the grounds of the study results it may be stated that the test item may lead to corneal damage. The test item is classified into Category 1 according to UN GHS classification criteria.

Justification for selection of skin irritation / corrosion endpoint:
Only one study available.

Justification for selection of eye irritation endpoint:
Only one study available.

Effects on eye irritation: corrosive

Justification for classification or non-classification

Based on the available information, the substance is classified as Eye Damage Category 1, H318 according to CLP Regulation (EC) no. 1272/2008.