Benzimidazole-2-thiol

Endpoint summary

Description of key information

Skin Irritation

The test compound was tested for its dermal irritation potential in New Zealand White Rabbits according to guideline OECD-404.

The dermal irritation index of New Zealand white rabbits is calculated as 0.00 and test compound can be classified under non irritant categories. Thus based on result obtained from present experimentation, it can be concluded that the test compound was non irritant to skin of the New Zealand white under test conditions.

Eye Irritation

The acute eye irritation study of the test chemical was conducted in New Zealand White Rabbits as per the Guideline OECD- 405.

The test chemical when applied to the eye of New Zealand white rabbit at the dose level of 0.1 gm did not produce any eye irritation. Furthermore, any lesions such as pannus, staining were not recorded throughout the observation period of 72 hours.

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Data is from experimental reports

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Principles of method if other than guideline:

The test compound was tested for its dermal irritation potential in New Zealand White Rabbits according to guideline OECD-404.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation:10 to 12 weeks
- Weight at study initiation: 2.0kg±200g
- Housing: Animals were housed individually in stainless steel cages provided with stainless steel mesh bottom and facilities for food and water bottle.
- Diet (e.g. ad libitum): Pelleted feed,ad libitum
- Water (e.g. ad libitum): Community tap water passed through ‘Aqua Guard on line water filter’, was kept in glass bottles, ad libitum
- Acclimation period: The healthy rabbits selected for study was acclimatized to standard laboratory condition for one week in experimental room under Veterinary examination.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22-25 deg.C
- Humidity (%):40-60%
- Air changes (per hr):10-15 air changes per hour
- Photoperiod (hrs dark / hrs light):12 hours artificial fluorescent light and 12 hours dark.

Type of coverage:

open

Preparation of test site:

shaved

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):0.5 gm

Duration of treatment / exposure:

4 hour

Observation period:

14 days

Number of animals:

Three female rabbits

Details on study design:

TEST SITE
Initial test
Area of exposure: The test compound in the amount of 0.5 gm was applied at the different sites on the shaven back skin of animal.
- % coverage: Approximately 6 cm2.
- Type of wrap if used: Adhesive tape

REMOVAL OF TEST SUBSTANCE
- Washing (if done): No data available
- Time after start of exposure:No data available

OBSERVATION TIME POINTS
(indicate if minutes, hours or days) 3 min ,1 hour ,4 hour,24,48 and 72 hours

SCORING SYSTEM:
- Method of calculation

Confirmatory test;
- Area of exposure:The test compound in the amount of 0.5 gm was applied at the different sites on the shaven back skin of animal.
- % coverage:Approximately 6 cm2.
- Type of wrap if used: Adhesive tape

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Cleaned with lukewarm water.
- Time after start of exposure: 4 hour

OBSERVATION TIME POINTS
(indicate if minutes, hours or days) ; 60 min ,24,48 and 72 hours

SCORING SYSTEM: Draize’s method.TEST SITE
:

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

14 d

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The test chemical applied at the dose level of 0.5 gm on shaven back skin of rabbit did not produced any irritation to skin during the period of observation.

Other effects:

Clinical Signs: The test chemical when applied on the shaven back skin of rabbit in the amount of 0.5 gm did not produce any clinical signs of toxicity throughout the examination period of 14 days.

INDIVIDUAL ANIMAL DERMAL IRRITATION SCORES

 

Rabbit No.	Sex	INTACT SKIN
		3 Min.		4 Hours		24 Hours		48 Hours		72 Hours		14 days
		Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema	Erythema	Oedema
01	F	0	0	0	0	0	0	0	0	0	0	0	0
02	F	-	-	0	0	0	0	0	0	0	0	0	0
03	F	-	-	0	0	0	0	0	0	0	0	0	0
Total		0	0	0	0	0	0	0	0	0	0	0	0
Mean		0	0	0	0	0	0	0	0	0	0	0	0
Grand Total		0.00

 

Dermal Irritation Index: 0.0/4 = 0.0

Table 2:

CLINICAL SIGNS

 

SEX	ANIMAL NO.	Time (Min.)	Time (Hours)					Time (Day)
		3	1	4	24	48	72	14
FEMALE	01	N	N	N	N	N	N	N
	02	N	N	N	N	N	N	N
	03	N	N	N	N	N	N	N

 

N: No Clinical Signs

C: Clinical Signs Observed

Interpretation of results:

other: not irritating

Conclusions:

The dermal irritation index of New Zealand white rabbits is calculated as 0.00 and test compound can be classified under non irritant categorie s. Thus based on result obtained from present experimentation, it can be concluded that the test compound was non irritant to skin of the New Zealand white under test conditions.

Executive summary:

The test compound was tested for its dermal irritation potential in New Zealand White Rabbits according to guideline OECD-404.

In the initial test one healthy rabbit of body weight 2.24 kg selected for study after acclimatization. The test compound in the amount of 0.5 gm was applied at the different sites on the shaven back skin of animal. The hairs of back sides were removed (approximately 6 cm²) with the help of electric clipper one day earlier before the treatment. Animal was also observed for any dermal irritation or skin related infection at the site of application one day earlier.

The site of application was covered with impervious dressing secured in position with adhesive tape. The first patch was applied on the shaven back skin of rabbit and removed after three minutes. No serious reaction was observed at the site of application. The second patch was applied on the different shaven back side and removed after one hour. There were no signs of skin reaction observed at this site of application. Finally, a third patch was applied at a different site and was removed after four hour. No skin reaction was observed at the site of application of test compound. Finally, the animal was observed for 14 days, for any irritation and corrosion. Because no corrosive effect was observed in the initial test, a confirmatory test was done using two additional animals. In the confirmatory test the test compound in the amount of 0.5 gm was applied on the shaven back skin of two animals (body weight ranges 2.14 and 2.09 kg), each with one patch, for an exposure period of four hours.

After four hours the patch was removed and the skin reactions were graded according to Draize’s method. The test chemical in the amount of 0.5 gm did not produce any dermal irritation in terms of erythema or edema in any of the animals after the four hours application. Both the animals were also free from any clinical signs of toxicity throughout the observation period of 14 days. The dermal irritation index of New Zealand white rabbits is calculated as 0.00 and test compound can be classified under non irritant categorie s. Thus based on result obtained from present experimentation, it can be concluded that the test compound was non irritant to skin of the New Zealand white under test conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Data is from study report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Principles of method if other than guideline:

The study was conducted to evaluate the acute eye irritation index of the test chemical in New Zealand White rabbits.

GLP compliance:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Details on test animals
- Age at study initiation: 10 to 12 weeks
- Weight at study initiation: 2.0kg ±200g
- Housing: Rabbit was housed in stainless steel cages provided with stainless steel mesh bottom and facilities for food and water bottle.
- Diet (e.g. ad libitum):Pelleted feed supplied ad libitum
- Water (e.g. ad libitum): Community tap water passed through ‘Aqua Guard on line water filter’ was kept in bottles, ad libitum.
- Acclimation period: The rabbit was acclimatized to standard laboratory condition for 24 hours in experimental room before study.

ENVIRONMENTAL CONDITIONS
- Temperature (°C):22-25 degC
- Humidity (%):40-60%
- Air changes (per hr):10-15 air changes per hour
- Photoperiod (hrs dark / hrs light): illumination cycle set to 12 hours artificial fluorescent light and 12 hours dark.

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 gm

Duration of treatment / exposure:

21 days

Observation period (in vivo):

1, 24, 48 and 72 hours.
To determine the reversibility of the effect the animal was observed normally for 21 days.

Number of animals or in vitro replicates:

Three female rabbits

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done):after 24 hrs.

SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: Biomicroscope and hand slit lamp further examined with the aid of fluorescein.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

21 d

Score:

0

Reversibility:

not specified

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

The test chemical when applied to the eye of New Zealand white rabbit at the dose level of 0.1 gm did not produce any eye irritation. Furthermore, any lesions such as pannus, staining were not recorded throughout the observation period of 72 hours.

Other effects:

Clinical Signs: The test chemical applied in conjunctival sac of rabbits at the dose level of 0.1 gm did not show any observable clinical signs such as cage side activity and pain or stress etc. throughout the observation period of 21 days.

GRADING OF OCULAR LESIONS

 

S.NO/ SEX		OBSERVATION	Score				Total	Total Score
1/F			1 hour	24hours	48 hours	72 hours
	Cornea	A.       Opacity-Degree of Density	0	0	0	0	0	0×0×5=0
		B.       Area of Cornea Involved	0	0	0	0	0
	Iris	A.       Values	0	0	0	0	0	0
	Conjunctivae	A.       Redness	0	0	0	0	0	0+0+0×5=0
		B.       Chemosis	0	0	0	0	0
		C.       Discharge	0	0	0	0	0
2/F	Cornea	A.       Opacity-Degree of Density	0	0	0	0	0	0×0×5=0
		B.       Area of Cornea Involved	0	0	0	0	0
	Iris	A.       Values	0	0	0	0	0	0
	Conjunctivae	A.       Redness	0	0	0	0	0	0+0+0×5=0
		B.       Chemosis	0	0	0	0	0
		C.       Discharge	0	0	0	0	0
3/F	Cornea	A.       Opacity-Degree of Density	0	0	0	0	0	0×0×5=0
		B.       Area of Cornea Involved	0	0	0	0	0
	Iris	A.       Values	0	0	0	0	0	0
	Conjunctivae	A.       Redness	0	0	0	0	0	0+0+0×5=0
		B.       Chemosis	0	0	0	0	0
		C.       Discharge	0	0	0	0	0
Grand total								0.00
Mean								0.00
Eye Irritation Scoring index								0.00

 

Interpretation of results:

other: not irritating

Conclusions:

The test chemical when applied to the eye of New Zealand white rabbit at the dose level of 0.1 gm did not produce any eye irritation. Furthermore, any lesions such as pannus, staining were not recorded throughout the observation period of 72 hours.

Executive summary:

The acute eye irritation study of the test chemical was conducted in New Zealand White Rabbits as per the Guideline OECD- 405.

One healthy rabbits of body weight 2.0kg was selected for study after acclimatization. Both eyes of rabbits were examined for any abnormal disch arge such as eye irritation, ocular defects or pre-existing corneal injury from eye 24 hours prior to application of test compound. Test chemical was applied in the conjunctival sac of rabbit after gently pulling the lower lid away from the eyeball at the dose rate of 0.1gm.The lids were then gently held for about one second in order to prevent loss of the material. The other eye which remain untreated, served as a control. The acute irritation to eye conjunctiva, cornea and iris was evaluated at 1, 24, 48 and 72 hours after the treatment. The grades of ocular reaction (conjunctiva, cornea and iris) were recorded at each observation. To determine the reversibility of the effect the animal was observed normally for 21 days. Any other lesions in the eye viz pannus, staining were observed and scored accordingly. Examination of reactions was facilitated by use of biomicroscope and hand slit lamp. Individual animal weight before and during the study was observed.

The test chemical failed to produce any eye irritation during the observation period in the initial test . Furthermore, no other clinical signs were recorded after application of test compound such as cage side activity, pain etc. The result obtained from the initial test was confirmed in additional two animals of same sex and same dose level (OECD-405).

Test compound was applied in the amount of 0.1 gm in the conjunctival sac of each rabbit after gently pulling the lower lid away from the eyeball.The other eye which remain untreated, served as a control. The acute irritation to eye conjunctiva, cornea and iris was evaluated at 1, 24, 48 and 72 hoursafter the treatment. The grades of ocular reaction (conjunctiva, cornea and iris) were recorded at each observation. To determine the reversibility of the effect the animals were observed normally for 21 days. Any other lesions in the eye viz pannus, staining were observed and scored accordingly. Examination of reactions was facilitated by use of biomicroscope and hand slit lamp. The test chemical when applied to the eye of New Zealand white rabbit at the dose level of 0.1 gm did not produce any eye irritation. Furthermore, any lesions such as pannus, staining were not recorded throughout the observation period of 72 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin Irritation

Various studies have been performed to evaluate dermal irritation potential of the test chemical in living organisms. These include in vivo experimental studies performed on rabbits, mice, rats for the test chemical.

The test compound was tested for its dermal irritation potential in New Zealand White Rabbits according to guideline OECD-404.

In the initial test one healthy rabbit of body weight 2.24 kg selected for study after acclimatization. The test compound in the amount of 0.5 gm was applied at the different sites on the shaven back skin of animal. The hairs of back sides were removed (approximately 6 cm2) with the help of electric clipper one day earlier before the treatment. Animal was also observed for any dermal irritation or skin related infection at the site of application one day earlier.

The site of application was covered with impervious dressing secured in position with adhesive tape. The first patch was applied on the shaven back skin of rabbit and removed after three minutes. No serious reaction was observed at the site of application. The second patch was applied on the different shaven back side and removed after one hour. There were no signs of skin reaction observed at this site of application. Finally, a third patch was applied at a different site and was removed after four hour. No skin reaction was observed at the site of application of test compound. Finally, the animal was observed for 14 days, for any irritation and corrosion. Because no corrosive effect was observed in the initial test, a confirmatory test was done using two additional animals. In the confirmatory test the test compound in the amount of 0.5 gm was applied on the shaven back skin of two animals (body weight ranges 2.14 and 2.09 kg), each with one patch, for an exposure period of four hours.

After four hours the patch was removed and the skin reactions were graded according to Draize’s method. The test chemical in the amount of 0.5 gm did not produce any dermal irritation in terms of erythema or edema in any of the animals after the four hours application. Both the animals were also free from any clinical signs of toxicity throughout the observation period of 14 days. The dermal irritation index of New Zealand white rabbits is calculated as 0.00 and test compound can be classified under non irritant categories. Thus based on result obtained from present experimentation, it can be concluded that the test compound was non irritant to skin of the New Zealand white under test conditions.

This is supported by the results of a study designed and conducted to determine the dermal reaction profile of the test chemical in Sprague Dawley rats. The study was performed as per OECD Guidelines 402 and complying to the GLP procedures. Ten rats (5 male and 5 female) were used for conducting dermal irritation /corrosion study.

The animals were kept in their cages for at least 5 days prior to administration for acclimatization to the laboratory condition and after acclimatization period, animals were randomly selected. Approximately 24 hours before application, the hair of each rat was closely clipped from the trunk (dorsal surface and sides from scapular to pelvic area) with an electric clipper, so as to expose at least 10% of the body surface area. The test item was applied directly onto the exposed skin of the animal, taking care to spread the test item evenly over the entire area of approximately 10% of the total body surface area or as much of the area as can reasonably be covered. The test item was held in contact with the skin using a porous gauze dressing and non irritating tape around the animal to cover the exposure site for first 24 hours exposure period. Elizabethan collar was placed on each animal for first 24 hours after application of the test item. These collars prevent ingestion of test item. Following 24 hours of exposure, the wrapping was removed and the test site wiped free of excess test item. Distilled water was used to remove residual test item.

 

The test chemical was applied to shorn skin of 5 male and 5 female animals at 2000 mg/kg body weight. Administration of the test item at 2000 mg/kg did not result in any skin reaction at the site of application during the study period of 14 days. Also, the erythema and edema score of rats was calculated as 0. Administration of the test item did not result in any signs of toxicity and mortality during the study period of 14 days. Animals exhibited normal body weight gain through the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment. Hence, it was concluded that the test chemical was Non-Irritating to the skin of Sprague Dawley rats under the experimental conditions tested and classified as “Category- Not Classified” as per CLP Classification.

This result is supported by the results of the studies performed on rats, mice and rabbits. In the investigation of local skin irritancy the test chemical gave no indications of irritant effects on rats, rabbit and mice. Hence, the test chemical can be considered to be not irritating to skin.

Since the test chemical failed to cause any signs of ocular irritation to the skin of the living organisms tested, it can be concluded that the test chemical certainly lacks the potential to cause any irritation to skin. It can be considered to be not irritating to skin. Comparing the above annotations with the criteria of CLP Regulation, the test chemical can be classified to be “Not Classified”.

Eye Irritation

Various studies have been reviewed to determine the level of ocular damage caused by the test chemical in living organisms. These include in vivo experimental studies performed on rabbits, mice, rats for the test chemical.

The acute eye irritation study of the test chemical was conducted in New Zealand White Rabbits as per the Guideline OECD- 405.

One healthy rabbits of body weight 2.0kg was selected for study after acclimatization. Both eyes of rabbits were examined for any abnormal discharge such as eye irritation, ocular defects or pre-existing corneal injury from eye 24 hours prior to application of test compound. Test chemical was applied in the conjunctival sac of rabbit after gently pulling the lower lid away from the eyeball at the dose rate of 0.1gm.The lids were then gently held for about one second in order to prevent loss of the material. The other eye which remain untreated, served as a control. The acute irritation to eye conjunctiva, cornea and iris was evaluated at 1, 24, 48 and 72 hours after the treatment. The grades of ocular reaction (conjunctiva, cornea and iris) were recorded at each observation. To determine the reversibility of the effect the animal was observed normally for 21 days. Any other lesions in the eye viz pannus, staining were observed and scored accordingly. Examination of reactions was facilitated by use of biomicroscope and hand slit lamp. Individual animal weight before and during the study was observed.

The test chemical failed to produce any eye irritation during the observation period in the initial test. Furthermore, no other clinical signs were recorded after application of test compound such as cage side activity, pain etc. The result obtained from the initial test was confirmed in additional two animals of same sex and same dose level (OECD-405).

Test compound was applied in the amount of 0.1 gm in the conjunctival sac of each rabbit after gently pulling the lower lid away from the eyeball. The other eye which remain untreated, served as a control. The acute irritation to eye conjunctiva, cornea and iris was evaluated at 1, 24, 48 and 72 hours after the treatment. The grades of ocular reaction (conjunctiva, cornea and iris) were recorded at each observation. To determine the reversibility of the effect the animals were observed normally for 21 days. Any other lesions in the eye viz pannus, staining were observed and scored accordingly. Examination of reactions was facilitated by use of biomicroscope and hand slit lamp. The test chemical when applied to the eye of New Zealand white rabbit at the dose level of 0.1 gm did not produce any eye irritation. Furthermore, any lesions such as pannus, staining were not recorded throughout the observation period of 72 hours.

This result is supported by the results of the studies performed on rats, mice and rabbits. In the investigation of local eye irritancy the test chemical gave no indications of irritant effects on rats, rabbit and mice. Hence, the test chemical can be considered to be not irritating to eyes.

Since the test chemical failed to cause any signs of ocular irritation to the eyes of the living organisms tested, it can be concluded that the test chemical certainly lacks the potential to cause any irritation to eyes. It can be considered to be not irritating to eyes. Comparing the above annotations with the criteria of CLP Regulation, the test chemical can be classified to be “Not Classified”.

Justification for classification or non-classification

Available studies for the test chemical indicate that it certainly lacks the potential to cause irritation to eyes and skin. The test chemical can be considered to be not irritating to eyes and skin. Hence, it can be classified under the category "Not Classified" as per CLP Regulation.