4-[(4-HYDROXYPYRIMIDIN-2-YL)AMINO]BENZONITRILE

Endpoint summary

Description of key information

Skin irritation

In a K2 in vivo skin irritation study in New Zealand White Rabbits according to OECD Guideline 404 and EU Method B.4, T002487 was found to be a mild irritant with a primary irritation index of 0.2. Based on CLP Regulation (EC) No 1272/2008, the test item is considered not to be classified (score < 2.3).

Eye Irritation:

In a K2 Rabbit Enucleated Eye Test (REET) test assessing the ocular irritancy potential by applying the test material onto the cornea of the enucleated eye, T002487 is considered to have the potential to cause severe ocular irritancy in vivo and should be classified as Category 1 according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations and the criteria of the CLP regulation (EC) No 1272/2008.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-11-10 to 2004-11-19

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

Study is conducted according to OECD Guideline 404 (Acute Dermal Irritation / Corrosion) and EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion); however, the test substance is not adequately characterized and insufficient information is provided on the test animals.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

: Insufficient information on the test substance and test animals.

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

: Insufficient information on the test substance and test animals.

GLP compliance:

no

Remarks:

The study was conducted in a facility operating to Good Laboratory Practice within the UK national GLP monitoring programme, but the study report has not been audited by the QA unit. No formal claim of GLP compliance is made for this study.

Specific details on test material used for the study:

no data

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
- source: 3 male NewZealand White Rabbits, no further data on test animals

ENVIRONMENTAL CONDITIONS: no data

Type of coverage:

semiocclusive

Preparation of test site:

other: intact

Vehicle:

not specified

Controls:

other: Untreated skin areas of the test animals served as control.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g
- Concentration (if solution): no data

VEHICLE: no data

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

Three

Details on study design:

TEST SITE
- Area of exposure: no data
- % coverage: no data
- Type of wrap if used: semi-occlusive, no further data

REMOVAL OF TEST SUBSTANCE: no data

OBSERVATION TIME POINTS
- Skin reactions were recorded 1, 24, 48 and 72 hours after administration.

SCORING SYSTEM:
- according to Draize
- Primary Irritation Index
0 = Non-irritant
>0 - 2 = Mild irritant
>2 - 5 = Moderate irritant
>5 - 8 = Severe irritant

Irritation parameter:

erythema score

Basis:

animal: 61

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

erythema score

Basis:

animal: 67

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

erythema score

Basis:

animal: 68

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48h

Irritation parameter:

edema score

Basis:

animal: 61

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

animal: 67

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

edema score

Basis:

animal: 68

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritant / corrosive response data:

An isolated incidence of very slight erythema was noted at one treated skin site at the 24-hour observation.

Skin Reaction	Observation Time	Individual Scores – Rabbit Number and Sex			Total
		61 Male	67 Male	68 Male
Erythema/Eschar Formation	1 Hour	0	0	0	(0)
	24 Hour	0	0	1	1
	48 Hour	0	0	0	(0)
	72 Hour	0	0	0	0
Oedema Formation	1 Hour	0	0	0	(0)
	24 Hour	0	0	0	0
	48 Hour	0	0	0	(0)
	72 Hour	0	0	0	0
Sum of 24 and 72 Hour Readings					1
Primary Irritation Index (S/6) and Classification					1/6=0.2
					Mild Irritant

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

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance was found to be a mild irritant with a primary irritation index of 0.2. Based on the criteria of the CLP regulation (EC) No 1272/2008, the test item is considered not to be classified (score < 2.3).

Reference 2

Endpoint:

skin irritation: in vitro / ex vivo

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

an in vitro skin irritation study does not need to be conducted because adequate data from an in vivo skin irritation study are available

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 2004-11-01 to 2004-11-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

While only a study summary was available for review which provided limited details on the test substance and methodology, sufficient information was provided to deem the study reliable with restrictions.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The ocular irritancy potential of the test material was assessed using the rabbit enucleated eye test (REET) SPL Standard Test Method 569.04. This method involved the application of the test material onto the cornea of the enucleated eye.

GLP compliance:

no

Remarks:

The study was conducted in a facility operating to Good Laboratory Practice within the UK national GLP monitoring programme, but the study report had not been audited by the QA Unit. No formal claim of GLP compliance was made for the study.

Specific details on test material used for the study:

no data

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: New Zealand White rabbits, no further data on test animals
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions): the enucleated eyes were maintained at a temperature of 32°C +/- 1.5°C within the superfusion apparatus.

Vehicle:

not specified

Controls:

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL of the test item, which had been found to weigh approximately 60 mg
- Concentration (if solution): no data

NEGATIVE CONTROL
- Amount(s) applied (volume or weight with unit): No data
- Concentration (if solution): 0.9%

Duration of treatment / exposure:

single application

Number of animals or in vitro replicates:

3 enucleated eyes were treated with the test item and 2 enucleated eyes were treated with the control.

Details on study design:

REMOVAL OF TEST SUBSTANCE: no data

OBSERVATION TIME POINTS
- corneal opacity and corneal epithelium condition: 60, 120, 180 and 240 min post dosing
- fluorescein uptake: 240 min post dosing
- corneal swelling: 60, 120 and 240 min post dosing

SCORING SYSTEM:
The direct effect of the test substance on the cornea was assessed by evaluation of corneal thickness, corneal opacity, alteration of corneal epithelium and fluorescein uptake, throughout the duration of the study.


TOOL USED TO ASSESS SCORE:
no data

Irritation parameter:

cornea opacity score

Remarks:

cloudiness/ mean of 3 eyes after 60, 120, 180 and 240 min post dosing

Run / experiment:

1

Value:

1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Irritation parameter:

cornea opacity score

Remarks:

area/mean of three eyes after 60, 120, 180 and 240 min post dosing

Run / experiment:

1

Value:

2.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Irritation parameter:

other: Fluorescein uptake

Remarks:

intensity/mean of three eyes

Run / experiment:

1

Value:

1

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Irritation parameter:

other: Fluorescein uptake

Remarks:

area/mean of three eyes

Run / experiment:

1

Value:

2

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Irritation parameter:

percent corneal swelling

Remarks:

mean of three eyes 60 min post dosing

Run / experiment:

1

Value:

13.7

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Irritation parameter:

percent corneal swelling

Remarks:

mean of three eyes 120 min post dosing

Run / experiment:

1

Value:

15.3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Irritation parameter:

percent corneal swelling

Remarks:

mean of three eyes 240 min post dosing

Run / experiment:

1

Value:

19.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

positive indication of irritation

Other effects / acceptance of results:

negative control eyes:
- corneal opacity: 0 (mean of 2 eyes)
- corneal epithelium condition: normal (2 eyes)
- fluorescein uptake: 0 (mean of 2 eyes)
- corneal swelling: 1.0 at 60 min post dosing, 1.1 at 120 minutes post dosing and 1.3 at 240 minutes post dosing

Corneal epithelium condition was normal at all timepoints for all test item treated eyes.

Table 1. Results obtained for corneal opacity at 60, 120, 180, and 240 minutes post exposure.

	Corneal Opacity
	Observation Period (minutes post dosing)
	60		120		180		240
	Cldy	Area	Cldy	Area	Cldy	Area	Cldy	Area
Test Eyes	1	3	1	4	1	4	1	4
	1	3	1	2	1	1	1	1
	1	2	1	2	1	1	1	1
Control Eyes	0	0	0	0	0	0	0	0
	0	0	0	0	0	0	0	0

Cldy = Corneal opacity

 

 

Table 2. Results obtained for corneal epithelium condition at 60, 120, 180, and 240 minutes post exposure.

	Corneal Epithelium Condition
	Observation Period (minutes post dosing)
	60	120	180	240
Test Eyes	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal
Control Eyes	Normal	Normal	Normal	Normal
	Normal	Normal	Normal	Normal

 

 

Table 3. Results obtained for fluorescein uptake 240 minutes post exposure.

	Fluorescein Uptake (240 minutes)
	Test Eyes			Control Eyes
Int	1	1	1	0	0
Area	4	1	1	0	0

Int = Intensity of fluorscein uptake

 

Table 4. Results obtained for corneal swelling at 60, 120, and 240 minutes post exposure.

	Corneal Swelling (%)(minutes post dosing)
	60	120	240
Test Eyes	13.7	15.3	19.6
Control Eyes	1.0	1.1	1.3

Test eyes results are the mean of three eyes while control eyes are the mean of two eyes

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

The test material is considered to have the potential to cause severe ocular irritancy in vivo.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation:

Sanders (2004) investigated acute dermal irritation of T002487 in 3 male New Zealand White rabbits after 4 hours of exposure to 0.5 g of test item. Skin reactions were recorded 1, 24, 48 and 72 hours after administration. There was an isolated incidence of very slight erythema (0.33) noted at one treated skin site at the 24-hour observation but was fully reversible within 48 hours. Under the conditions of this study, the test item was found to be a mild irritant. However, based on the criteria of the CLP Regulation (EC) No 1272/2008, the test item is considered not to be classified (score < 2.3).

 

An in vitro skin irritation study was waived based on the justification that adequate data from an in vivo skin irritation study are available.

 

Eye irritation:

The rabbit enucleated eye test (REET) was performed by Sanders (2004) to assess the ocular irritancy potential of T002487. 0.1 mL of test item (which weighed approximately 60 g) was applied onto the cornea of three enucleated eyes, obtained from the New Zealand White strain of rabbit. Corneal opacity (60, 120, 180 and 240 minutes after application), corneal swelling (60, 120 and 240 minutes after application) and fluorescein uptake (240 minutes after application) were observed and scored. The corneal opacity mean score of 3 eyes was 1, fluorescein uptake mean score was 1 and the percent corneal swelling mean of 3 eyes at 60, 120 and 240 minutes was 13.7, 15.3 and 19.6, respectively. The test item is considered to have the potential to cause severe ocular irritancy in vivo.

 

Justification for classification or non-classification

Skin irritation:

According to the in vivo acute dermal irritation study, no skin irritation was noted for T002487. The test item did not meet the criteria for classification as irritant or corrosive according to the criteria of the CLP regulation (EC) No 1272/2008.

Eye irritation:

According to the in vitro eye irritation study (REET), T002487 induced ocular irritation and should be classified for eye damage Category 1 according to the criteria of the CLP regulation (EC) No 1272/2008.