3,4-dihydro-2H-1,4-benzoxazin-6-ol

Endpoint summary

Description of key information

Based on the results of the three available in vivo key studies (Clouzeau, OECD TG 404, GLP, 1994, Klimisch 1; SIRE, OECD TG 405, GLP, 2005, Klimisch 1 and Clouzeau, OECD TG 405, GLP, 1994, Klimisch 1), the registered substance hydroxybenzomorpholine is not classified for skin and eye irritation according to the CLP criteria.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 05 May 1994 to 25 August 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Elevage Cunicole de Val de Selle, 80160 Prouzel, France
- Age at study initiation: not specified
- Weight at study initiation: mean body weight of 2.4 ± 0.1 kg
- Housing: the animals were housed individually in polystyrene cages (35 x 55 x 32 em or 48.2 x 58 x 36.5 em). Each cage was equipped with a food container and a water bottle.
- Diet (e.g. ad libitum): All the animals had free access to 112 C pelleted diet (U.A.R., 91360 Villemoisson-sur-Orge, France).
- Water (e.g. ad libitum): drinking water filtered by a F.G. Millipore membrane (0.22 micron) and contained in bottles was provided ad libitum.
- Acclimation period: at least 5 days before the beginning of the study

There were no contaminants in the diet or water at levels likely to have influenced the outcome of the study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES: From 25 May 1994 To 28 May 1994

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
A dose of 500 mg of the test substance in its original form was applied to a 6 cm² hydrophilic gauze patch moistened with 0.5 ml of water for injections and this was then applied to the right flank.

NEGATIVE CONTROL
The left flank did not receive any test substance and served as control.

Duration of treatment / exposure:

The test substance was applied to the right flank of rabbits for 4 hours.

Observation period:

The skin was examined approximately 1, 24, 48 and 72 hours after removal of the dressing. When there is no evidence of dermal irritation after 72 hours, the study is ended. Any change in the animals' behaviour was noted.

Number of animals:

3

Details on study design:

TEST SITE
The day before treatment, the flanks of each animal were clipped using electric clippers. Only animals showing no obvious signs of irritancy were used for the study.
The test substance and the gauze patch were held in contact with the skin by means of an adhesive hypoallergenic aerated semi-occlusive dressing and a restraining bandage.

REMOVAL OF TEST SUBSTANCE
Four hours after application, the dressings were removed and any residual test substance was removed with a dry gauze patch.

OBSERVATION TIME POINTS
1, 24, 48 and 72 hours after removal of the dressing

SCORING SYSTEM:
Dermal irritation was evaluated for each animal according to the following scoring scale:

Erythema and eschar formation:
no erythema .......................................................................................................... 0
very slight erythema (barely perceptible) ............................................................. 1
well-defined erythema .......................................................................................... 2
moderate to severe erythema ............................................................................. 3
severe erythema (beet redness) to slight eschar formation (injuries in depth) 4

Oedema formation
no oedema............................................................................................................. 0
very slight oedema (barely perceptible) .............................................................. 1
slight oedema (edges of area well-defined by definite raising) ......................... 2
moderate oedema (raised approximately 1 millimetre)...................................... 3
severe oedema (raised more than 1 millimetre and extending beyond area
of exposure) .......................................................................................................... 4

Any other lesions were noted.

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No cutaneous reactions were observed during the study.

Other effects:

None.

Table 1: Individual cutaneous examinations and mean score of the values recorded after 24, 48 and 72 hours for each animal

Rabbit number	Dermal irritation	Scores				Mean irritation scores (24, 48, 72h)	Interpretation
		1h	24h	48h	72h
01	Erythema	0	0	0	0	0.0	Non-irritant
	Oedema	0	0	0	0	0.0	Non-irritant
	Other	none	none	none	none
02	Erythema	0	0	0	0	0.0	Non-irritant
	Oedema	0	0	0	0	0.0	Non-irritant
	Other	none	none	none	none
03	Erythema	0	0	0	0	0.0	Non-irritant
	Oedema	0	0	0	0	0.0	Non-irritant
	Other	none	none	none	none

 

 

Interpretation of results:

GHS criteria not met

Conclusions:

Under the experimental conditions of this test, the test substance hydroxybenzomorpholine was considered as non-irritant when administered by cutaneous route in rabbits.

Executive summary:

Approximately 24 hours prior to the application of hydroxybenzomorpholine, the flanks of 3 male rabbits were clipped free of fur. A 500 mg sample of neat hydroxybenzomorpholine moistened with 0.5 ml water was applied to a 6 cm² area of the right flank of each animal (the untreated left flank served as control). It was held in contact with the skin for 4 hours by means of a semiocclusive dressing.

Subsequently, the dressings were removed, any residual test substance was removed and the treated area was observed 1, 24, 48 and 72 hours afterwards.

Results
There were no skin reactions at any observation time-point.

Conclusion
Under the conditions of this study, hydroxybenzomorpholine was non-irritating to rabbit skin when tested undiluted.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 5 May 1994 to 30th August 1994

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

24th February 1987

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Elevage Cunicole de Val de Selle, 80160 Pouzel, France
- Age at study initiation: not specified
- Weight at study initiation: 2.5 +/- 0.1 kg
- Housing: the animals were housed individually in polystyrene cages (35 x 55 x 32 cm) or (48.2 x 58 x 36.5 cm). Each cage was equipped with a food container and a water bottle.
- Diet (e.g. ad libitum): free access to 112 pelleted diet. Each batch of food was analysed by the supplier
- Water (e.g. ad libitum): drinking water filtered by a F.G. Millipore membrane (0.22 micron) and contained in bottles was provided ad libitum.
- Acclimation period: at least 5 days before

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18+/- 3°C
- Humidity (%): 30 to 70 %
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12h/12h

IN-LIFE DATES: From: 1 June 1994 To: 5 June 1994

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
- Concentration (if solution):

VEHICLE
- Amount(s) applied (volume or weight with unit):
- Concentration (if solution):
- Lot/batch no. (if required):
- Purity:

Duration of treatment / exposure:

A single introduction of 100 mg of the test substance in its original form was placed into the conjunctival sac of the left eye of 3 animals after gently pulling the lower lid away from the eyeball. The lower and upper eyelids were held together for about one second to avoid any loss of test substance. The right eye, which remained untreated, served as a control.
The eyes were not rinsed after administration of the test substance.

Observation period (in vivo):

Date of treatment: 1.6.94 (day 1)
End of the observation period: 4.6.94 or 5.6.94.
The eye were examined approximately 1, 24, 48, 72 hours after administration of the test substance.
When there is persistent ocular irritation after 72h, the observation period is extended to a maximum of 21 days (unti day 22) in order to determine the progress of the lesions and their reversibility of irreversibility. Any change in the behaviour was noted.

Number of animals or in vitro replicates:

3 animals

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): no


SCORING SYSTEM:

TOOL USED TO ASSESS SCORE: hand-slit lamp / biomicroscope / fluorescein

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.3

Max. score:

3

Reversibility:

fully reversible within: 4 days

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 3 days

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 4 days

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 3 days

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

2

Reversibility:

fully reversible within: 4 days

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 3 days

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.7

Max. score:

1

Reversibility:

fully reversible within: 4 days

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 3 days

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 5 days

Table 1: Individual ocular examinations and mean score of the values recorded after 24, 48 and 72 hours for each animal

Rabbit number	Ocular region	Description of ocular reactions	Scores					Mean irritation scores (24, 48, 72h)	Interpretation
			1h (D1)	24h (D2)	48h (D3)	72h (D4)	96h (D5)
01	Conjunctivae	Chemosis	3	3	1	0		1.3	Non-irritant
		Redness	1	2	1	0		1.0	Non-irritant
		Discharge	0	2	0	0		0.7
	Iris		0	0	0	0		0.0	Non-irritant
	Corneal opacity	Intensity	0	1	1	0		0.7	Non-irritant
		Area	0	2	1	0		1.0
	Other		none	none	none	none
02	Conjunctivae	Chemosis	2	0	0	0		0.0	Non-irritant
		Redness	2	1	0	0		0.3	Non-irritant
		Discharge	2	0	0	0		0.0
	Iris		0	0	0	0		0.0	Non-irritant
	Corneal opacity	Intensity	0	1	0	0		0.3	Non-irritant
		Area	0	1	0	0		0.3
	Other		none	none	none	none
03	Conjunctivae	Chemosis	3	1	0	0	0	0.3	Non-irritant
		Redness	1	2	1	0	0	1.0	Non-irritant
		Discharge	2	2	0	0	0	0.7
	Iris		0	1	0	0	0	0.3	Non-irritant
	Corneal opacity	Intensity	0	1	1	1	0	1.0	Non-irritant
		Area	0	4	2	2	0	2.7
	Other		none	none	none	none	none

D = day

 

 

 

Interpretation of results:

GHS criteria not met

Conclusions:

As the mean scores for chemosis, redness, iris, degree of corneal opacity for 2 out of the 3 animals did not reach the criteria values for irritation, under the experimental conditions of the test, Hydroxybenzomorpholine was considered as non-irritant when administered by ocular route in rabbits.

Executive summary:

A 100 mg sample of neat hydroxybenzomorpholine was instilled into the conjunctival sac of the left eye of 3 male rabbits after gently pulling the lower lid away from the eye ball. The lids were then held together for about one second to avoid any loss of test substance, and the eyes were not rinsed after instillation. The untreated right eye served as control, and ocular reactions were assessed 1, 24, 48, 72 and 96 hours after instillation.

Results
Marked conjunctival reactions (marked chemosis, slight to moderate redness) were observed in all animals one hour after instillation. These conjunctival reactions fully disappeared within 72 hours of instillation. Moderate to marked corneal opacity was observed in all animals on the day after instillation and fully disappeared within 96 hours. Isolated ocular discharge and minimal iris lesions were also observed.

Conclusion
Under the conditions of this study, hydroxybenzomorpholine was considered to be moderately irritating to rabbit eyes when tested undiluted.

Reference 2

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 december 2003 to 4 May 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

24th April 2002

GLP compliance:

yes

Specific details on test material used for the study:

• name:
- Study plan: Hydroxybenzomorpholine (A025)
- labeling: 2484
• INCI name: Hydroxybenzomorpholine
• COLIPA code: A025
• chemical name: 6-Hydroxybenzomorpholine
• trade name: IMEXINE OV
• CAS registry number: 26021-57-8
• other code: 2484
The INCI name (COLIPA code in brackets) is the denomination selected for the study report.
• batch number: 0508918
• description: brown powder
• storage conditions: at +4°C, protected from light and under nitrogen gas
• containers: four glass flasks
• date of receipt: 9 December 2003
• titre: 98.3%
• expiry date: September 2005.

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
Sex, species, strain: male New Zealand White rabbits.
Reason for this choice: species generally accepted by regulatory authorities for this type of study.
Breeder: CEGAV, Saint Mars d'Egrenne, France.
Number: three animals were used, as recommended by the international guidelines.
Age/weight: on the day of treatment, the animals were 2 to 4 months old and had a mean body weight ± standard deviation of 2.8 ± 0.2 kg.
Acclimation: at least 5 days before the beginning of the study. Identification: individual metal ear tag.


ENVIRONMENTAL CONDITIONS
The conditions in the animal room were set as follows:
• temperature: 18 ± 3°C
• relative humidity: 30 to 70%
• light/dark cycle: 12 h/12 h
• ventilation: approximately 12 cycles/hour of filtered, non-recycled air.
The temperature and relative humidity were under continuous control and recording. The records were checked daily and filed. In addition to these daily checks, the housing conditions and corresponding instrumentation and equipment were verified and calibrated at regular intervals.
The animals were housed individually in polystyrene cages (48.2 cm x 58 cm x 36.5 cm). Each cage was equipped with a food container and a water bottle.

Food and water
During the study, the animals had free access to 110 pelleted diet (SAFE, Villemoisson, Epinay-sur-Orge, France).
Food is analysed regularly by the supplier for composition and contaminant levels.
Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum. Bacteriological and chemical analyses of water are performed regularly by external laboratories. These analyses include the detection of possible contaminants (pesticides, heavy metals and nitrosamines).

No contaminants were known to have been present in the diet or drinking water at levels which may be expected to have interfered with or prejudiced the outcome of the study.


IN-LIFE DATES: From: 27 April 2004 To: 2 May 2004

Vehicle:

other: 0.5% suspension of carboxymethylcellulose

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
The test item was prepared at the concentration of 2% (w/w) in the vehicle.
Before preparation, the vehicle was degassed by sonication for at least 15 minutes and then saturated with nitrogen gas, and kept under nitrogen atmosphere for 15 minutes.
The test item was prepared as a solution in the vehicle by mixing the test item with the required quantity of vehicle.
The test item dosage forms were prepared extemporaneously under nitrogen atmosphere and were stored protected from light (using a glass beaker covered with aluminium foil) and under nitrogen atmosphere before use. They were used within the 6 hours following the preparation according to the known stability results (CIT/Study No. 26976 AHS).

The pH of the dosage form, measured at CIT, was approximately 7.52

VEHICLE
The vehicle used was a 0.5% suspension of carboxymethylcellulose: carboxymethylcellulose, batch No. 101K0185 (Sigma, Saint-Quentin-Fallavier, France) in purified water (prepared at CIT by reverse osmosis).

Duration of treatment / exposure:

A single dose of 0.1 mL of the test item at the concentration of 2% was instilled into the conjunctival sac of the left eye after gently pulling the lower lid away from the eyeball.
The eyes were not rinsed after administration of the test item.

Observation period (in vivo):

The eyes were examined approximately 1 hour, 24, 48 and 72 hours after administration of the test item.
The study was ended on day 4 in the absence of persistent ocular reactions.

A single dose of 0.1 mL of the test item at the concentration of 2% was instilled into the conjunctival sac of the left eye after gently pulling the lower lid away from the eyeball.

Number of animals or in vitro replicates:

The dosage form was first administered to a single animal (No. 347). Since the test item was not irritant on this first animal, it was then evaluated on two other animals (Nos. 349 and 350)

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The eyes were not rinsed after administration of the test item.


SCORING SYSTEM:
Conjunctival reactions, iritis and corneal opacification were evaluated daily for each animal.
For the evaluation of corneal opacification (presence or absence, affected area), the eyes were examined under a UV lamp after instillation of one or two drops of 0.5% sodium fluorescein solution (a clear fluorescence is visible in the areas of opacification). This evaluation was performed on day 2 and repeated thereafter whenever necessary.

Ocular reactions were scored according to the following numerical scale:

Conjunctival lesions and discharge
Chemosis (lids and/or nictitating membranes)
. no swelling 0
. any swelling above normal (includes nictitating membranes) 1
. obvious swelling with partial eversion of lids 2
. swelling with lids about half-closed 3
. swelling with lids more than half-closed 4
Redness (refers to palpebral and bulbar conjunctivae, cornea and iris)
. blood vessels normal 0
. a number of blood vessels definitely hyperemic (injected) 1
. diffuse, crimson colour, individual vessels not easily discernible 2
. diffuse, beefy red 3
Discharge
. absence of discharge 0
. slight discharge (does not include small amounts normally found in
inner canthus) 1
. discharge with moistening of lids and hairs adjacent to lids 2
. discharge with moistening of lids and hairs on wide area around the eye 3
Iris lesions
. normal 0
. markedly deepened rugae, congestion, swelling, moderate circum-corneal hyperemia, or injection, any of these or combination of any thereof, iris still
reacting to light (sluggish reaction is positive) 1
. no reaction to light, haemorrhage, gross destruction (any or all of these) 2
Corneal lesions
Degree of opacity (area most dense taken for reading)
. no ulceration or opacity 0
. scattered or diffuse areas of opacity (other than slight dulling or normal lustre),
details of iris clearly visible 1
. easily discernible translucent area, details of iris slightly obscured 2
. nacreous areas, no details of iris visible, size of pupil barely discernible 3
. opaque cornea, iris not discernible through the opacity 4
Area of opacity
. one quarter (or less) but not zero 1
. greater than one quarter but less than a half 2
. greater than one half but less than three quarters 3
. greater than three quarters up to whole area 4

Any other lesions observed were noted.


TOOL USED TO ASSESS SCORE: UV lamp

Irritation parameter:

cornea opacity score

Basis:

animal: 1,2,3

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

animal: 1,2,3

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Basis:

animal: 1,2,3

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

0

Remarks on result:

no indication of irritation

Irritation parameter:

chemosis score

Basis:

animal: 1,2,3

Time point:

24/48/72 h

Score:

ca. 0

Max. score:

0

Remarks on result:

no indication of irritation

Table 1: Individual ocular examinations and mean values of the scores recorded for each animal (24, 48 and 72 hours)

 

 

Rabbit number	Region of eye	Description ofocular reactions	Scores                                                                               1h              24h                  48h            72h	Mean irritation score(1)
			D1              D2              D3              D4
347	Conjunctivae	Chemosis	1                 0                 0                 0	0.0
		Redness	2                 0                 0                 0	0.0
		Discharge	0                 0                 0                 0	0.0
	Iris		0                 0                 0                 0	0.0
	Corneal opacity	Intensity	0                 0                 0                 0	0.0
		Area	0                 0                 0                 0	0.0
	Other Fluorescein		*                 *                 *                   * /                 U                 /                  /
349	Conjunctivae	Chemosis	0                 0                 0                 0	0.0
		Redness	0                 0                 0                 0	0.0
		Discharge	0                 0                 0                 0	0.0
	Iris		0                 0                 0                 0	0.0
	Corneal opacity	Intensity	0                 0                 0                 0	0.0
		Area	0                 0                 0                 0	0.0
	Other Fluorescein		*                 *                 *                   * /                 U                 /                  /
350	Conjunctivae	Chemosis	0                 0                 0                 0	0.0
		Redness	0                 0                 0                 0	0.0
		Discharge	0                 0                 0                 0	0.0
	Iris		0                 0                 0                 0	0.0
	Corneal opacity	Intensity	0                 0                 0                 0	0.0
		Area	0                 0                 0                 0	0.0
	Other Fluorescein		*                 *                 *                   * /                 U                 /                  /

 

(1)  mean of scores on days 2, 3 and4 h =hour

D = day

* = none

U = fluorescein batch No. H586

/ = fluorescein not used

 

Interpretation of results:

study cannot be used for classification

Conclusions:

Under our experimental conditions, the test item Hydroxybenzomorpholine (A025) (batch No. 0508918) at the concentration of 2% in a 0.5% suspension of carboxymethylcellulose is non-irritant when administered by ocular route to rabbits.

Executive summary:

A 0.1 ml aliquot of a 2% solution of hydroxybenzomorpholine in 0.5% aqueous carboxymethylcellulose was instilled into the left conjunctival sac of test animals. The eyes were not rinsed following instillation of the test item. The non-treated right eye served as control, and ocular reactions were assessed 1, 24, 48 and 72 hours after instillation.

Results

Ocular reactions were seen in 1 animal with slight chemosis (grade 1) and slight redness of conjunctivae (grade 2) at 1 hour after instillation only.

Conclusion

Under the conditions of this study, hydroxybenzomorpholine at 2% in 0.5% aqueous carboxymethylcellulose was transiently irritating to rabbit eyes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Two key studies were available for skin irritation evaluation and one key study for eye irritation evaluation:

An in vivo GLP compliant skin irritation test of hydroxybenzomorpholine was performed in three New Zealand White rabbits (OECD TG 404, GLP, 1994, Klimisch 1).

The neat test item was applied as a single dose of 500 mg under semi-occlusive dressing. After 4h, the remaining test item was removed. The irritancy of the test item was evaluated according to the Draize method. Animals were examined at 1, 24, 48, and 72 hours after the patch removal.

There were no skin reactions at any observation time-point. The animals’ individual mean scores (24, 48 and 72 hours after patch removal) for erythema and edema were all 0.00. In conclusion, under the experimental conditions of the study, the results indicate that the test item is non-irritant to skin.

An in vivo GLP compliant eye irritation test of hydroxybenzomorpholine test item was performed in New Zealand White rabbits (OECD TG 405, GLP, 1994, Klimisch 1). The test item was applied as a single dose of 100 mg into the conjunctival sac of one eye of each of the three New Zealand White rabbits. The degree of eye irritation/corrosion was evaluated by scoring lesions of conjunctivae, cornea and iris on both right and left eyes 1h, 24, 48, 72 and 96 hours following treatment. Marked conjunctival reactions (marked chemosis, slight to moderate redness) were observed in all animals one hour after instillation. These conjunctival reactions fully disappeared within 72 hours of instillation. Moderate to marked corneal opacity was observed in all animals on the day after instillation and fully disappeared within 96 hours. Isolated ocular discharge and minimal iris lesions were also observed.

The animals’ individual mean scores (24, 48 and 72 h) for corneal opacity were 0.7, 0.3 and 1.0 respectively. The animals’ individual mean scores (24, 48 and 72 h) for iris were 0.0, 0.0 and 0.3 respectively. The animals’ individual mean scores (24, 48 and 72 h) for conjunctivae were 1.0, 0.3 and 1.0 respectively. The animals’ individual mean scores (24, 48 and 72 h) for chemosis were 1.3, 0.0 and 0.3 respectively.

In conclusion, under the experimental conditions of the study, the test substance hydroxybenzomorpholine, was only moderately irritating to rabbit eyes when tested undiluted. The mean scores for chemosis, redness, iris, degree of corneal opacity for 2 out of the 3 animals have not reached the CLP regulation criteria values for classification as eye irritant.

In a second GLP compliant in vivo eye irritation study (OECD TG 405, GLP, 2005, Klimisch 1), a 0.1 ml aliquot of hydroxybenzomorpholine diluted at 2% in 0.5% aqueous carboxymethylcellulose was instilled into the left conjunctival sac of rabbit animals. The eyes were not rinsed following instillation of the test item. The non-treated right eye served as control, and ocular reactions were assessed 1, 24, 48 and 72 hours after instillation. Ocular reactions were seen in 1 animal with slight chemosis (grade 1) and slight redness of conjunctivae (grade 2) at 1 hour after instillation only.

The animals’ individual mean scores (24, 48 and 72 h) for corneal opacity, iris, conjunctivae and chemosis were all 0.

In conclusion, under the experimental conditions of the study, the test substance hydroxybenzomorpholine diluted at 2%, was only transiently irritating to rabbit eyes.

Justification for classification or non-classification

Based on the three available key studies (Clouzeau, OECD TG 404, GLP, 1994, Klimisch 1; SIRE, OECD TG 405, GLP, 2005, Klimisch 1 and Clouzeau, OECD TG 405, GLP, 1994, Klimisch 1)

, the registered substance hydroxybenzomorpholine did not induce skin irritation and did not induce eye irritation when diluted at 2% and was only moderately irritating to eyes when tested undiluted. As the mean scores for chemosis, redness, iris, degree of corneal opacity for 2 out of the 3 animals have not reached the criteria values for eye irritation, the neat test substance is not classified as eye irritant under Regulation (EC) n°1272/2008 (CLP). Hence, based on the overall data, hydroxybenzomorpholine does not require classification for skin and eye irritation according to the CLP criteria.