1-[2-(2-chloroethoxy)phenylsulfonyl]-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)urea;triasulfuron (ISO)

Endpoint summary

Description of key information

- Skin irritation: not irritating, female, New-Zealand White rabbit, OECD TG 404, Petus 2012

- Eye irritation: not irritating, male, New-Zealand White rabbit, OECD TG 405, Török 2012

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:

25 Jun 2012 to 30 Jun 2012

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:

202

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2500 (Acute Dermal Irritation)

Version / remarks:

1998

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Sex: Male
- Age at study initiation: ~10 weeks
- Weight at study initiation: 2817-2941 g
- Housing: Animals were housed individually in AAALAC approved metal wire rabbit cages. Cages are of an open wire structure and cages are placed together to allow some social interaction with rabbit(s) in adjoining cages.
- Diet: UNI diet for rabbits. Ad libitum
- Water: Tap water. Ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20.1-24 °C
- Humidity: 50-83 %
- Air changes: 15-20 air exchanges/hour
- Photoperiod: 12/12 hours light/dark

IN-LIFE DATES: From: 25 June 2012 to 30 June 2012

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Remarks:

The test item was moistened with the smallest of water sufficient to ensure good skin contact

Controls:

no

Amount / concentration applied:

0.5 g (per animal)

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: An area of 10 x 10 cm on the back and flanks of the rabbits was clipped with an electric clipper 24 hours before the treatment.
- Type of wrap if used: A surgical gauze pad (ca. 2.5 x 2.5 cm) was applied to the intact skin of the clipped area and was kept in contact with the skin by a patch with a surrounding adhesive hypoallergenic plaster. The entire trunk of the animals was than wrapped with plastic wrap held in place with an elastic stocking.

REMOVAL OF TEST SUBSTANCE
- Washing: The dressing was then removed and the skin was flushed with lukewarm tap water to clean the application site.
- Time after start of exposure: 4 hours

OBSERVATION TIME POINTS
- 1, 24, 48 72 hours after the end of exposure

SCORING SYSTEM:
- Method of calculation: The skin reaction was assessed according to the numerical scoring system listed in the Commission Directive 2004/73/EC, April 29, 2004 which was based on the Draize scoring system. For criteria, see 'Any other information on materials and methods incl. tables'.

OTHER OBSERVATIONS
- Clinical signs, including viability/mortality, were recorded daily from the day of application of the animals to the termination of the test.
- Body weights were recorded on the day of application and the end of the observation period.

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

8

Irritant / corrosive response data:

The primary irritation index was 0.00 (out of a maximum score of 8.0). No corrosive effects were noted on the treated skin of any animal at any of the observation intervals.

Other effects:

No clinical signs were observed in the animals during the study and no mortality occurred.
The body weights of all rabbits were considered to be within the normal range of variability

Interpretation of results:

GHS criteria not met

Conclusions:

The application of the test item did not result in any signs of skin irritation.
According to the Draize classification criteria the test item is considered to be “Not- Irritant” to rabbit skin.

Executive summary:

In an OECD TG 404 dermal irritation study performed under GLP, young adult New Zealand white rabbits (3 males) were exposed to 0.5 g the test item, applied to the intact shaved flank under a semi-occlusive dressing for 4 hours. Skin reactions were scored at 1, 4, 24, 48 and 72 hours after removal of the dressings for erythema and oedema. In addition, the Primary Irritation Index (PII) was calculated.

There were no signs of dermal irritation and the primary irritation index was calculated to be 0.00.

No local dermal signs were observed in the treated animals throughout the study and the 24/48/72h average scores were 0 for both erythema and oedema. There were no clinical signs of systemic toxicity and no mortalities. The body weights of all rabbits were considered to be within the normal range of variability. The study was terminated after the 72 hour observation period.

According to the Draize classification criteria the test item is considered to be “not-irritant” to rabbit skin.

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

Study period:

18 Jul 2012 to 23 Jul 2012

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:

2002

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Version / remarks:

1998

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Version / remarks:

2008

Qualifier:

according to guideline

Guideline:

other: Directive 2004/73/EC B.5 (L 152 2004)

Version / remarks:

2004

GLP compliance:

yes (incl. QA statement)

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Sex: Male
- Age at study initiation: Approximately 12 weeks
- Weight at study initiation: 3110– 3328 g
- Housing: Rabbits were individually housed in AAALAC approved metal wire rabbit cages. Cages were of an open wire structure and cages were placed together to allow some social interaction with rabbit(s) in adjoining cages.
- Diet: UNI diet for rabbits. Ad libitum
- Water: Tap water. Ad libitum
- Acclimatisation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 3 °C
- Humidity: 48 – 73 %
- Air changes: 15-20 air exchanges/hour
- Photoperiod: 12 hours of light/12 hours of dark

IN-LIFE DATES: From: 18 July 2012 To: 23 July 2012

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

0.1 g

Duration of treatment / exposure:

The test item was administered as an instillation of a single dose

Observation period (in vivo):

72 hours

Number of animals or in vitro replicates:

3

Details on study design:

PRE-STUDY EXAMINATION
- The pH of the test material was measured as pH 5.0, permitting the test material to be used in the animal studies.
- The test was performed on 3 male rabbits. Before the start of the test, both eyes of the provisionally selected test rabbits were examined for evidence of ocular irritation or defect using a hand-held slit-lamp. Only animals free of ocular damage were used. The eyes were not anaesthetised.

APPLICATION
The test material was placed into the conjunctival sac of the left eye, formed by gently pulling the lower lid away from the eyeball. The upper and lower eyelids were held together for several seconds immediately after treatment, to prevent loss of the test material

OBSERVATION TIME POINTS
Assessment of ocular damage/irritation was made approximately 1, 24, 48 and 72 hours following treatment. The eyes were further examined using 2% fluorescein solution approximately 24 hours before treatment and then 24, 48 and 72 hours after treatment

SCORING SYSTEM:
The eye irritation scores were evaluated according to the scoring system by Draize (1977). A modified version of the system described by Kay J H and Calandra J C (1962) was used to classify the ocular irritancy potential of the test material. For criteria, see 'Any other information on materials and methods incl. tables'.

TOOL USED TO ASSESS SCORE: fluorescein

OTHER OBSERVATIONS
- Individual body weight was recorded at dosing and at termination.

Irritation parameter:

chemosis score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal: #2, #3

Time point:

24/48/72 h

Score:

0.67

Max. score:

3

Reversibility:

fully reversible within: 72 h

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Remarks on result:

other:

Irritation parameter:

iris score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

no indication of irritation

Irritation parameter:

cornea opacity score

Basis:

animal: #1, #2, #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

An Initial Pain Reaction (IPR) score of 2 was observed in all animals.
Conjunctival redness (score 2) was seen in all rabbits and conjunctival discharge (score 1) was observed in two animals at 1 hour after treatment. Conjunctival discharge had reversed in all animals at the 24 hour observation. Conjunctival redness had reversed at the 72 hours observation.
Fluorescein staining was negative in all animals at any time point.
As all signs of eye irritation had fully reversed, the study was terminated after a period of 72 hours observation.

Other effects:

- The body weights of all rabbits were considered to be within the normal range of variability.
- No clinical signs of systemic toxicity were observed in any animals in this study.
- No mortality occurred in this study.

Table 3. Individual Draize Scores and Individual Total Scores* for Ocular Irritation

 

Rabbit number and sex		Male #1			Male #2				Male #3
		IPR = 2				IPR = 2				IPR = 2
Time after treatment	1 Hr	24 Hr	48 Hr	72 Hr	1 Hr	24 Hr	48 Hr	72 Hr	1 Hr	24 Hr	48 Hr	72 Hr
CORNEA E = Degree of Opacity F = Area of Cornea involved	0   0	0   0	0   0	0   0	0   0	0   0	0   0	0   0	0   0	0   0	0   0	0   0
* Score (E x F) x 5	0	0	0	0	0	0	0	0	0	0	0	0
IRIS D = Values	0	0	0	0	0	0	0	0	0	0	0	0
* Score (D x 5)	0	0	0	0	0	0	0	0	0	0	0	0
CONJUNCTIVAE A = Redness B = Chemosis C = Discharge	2 0 0	1 0 0	0 0 0	0 0 0	2 0 1	1 0 0	1 0 0	0 0 0	2 0 1	1 0 0	1 0 0	0 0 0
* Score (A+B+C) x 2	4	2	0	0	6	2	2	0	6	2	2	0
* Total Score	4	2	0	0	6	2	2	0	6	2	2	0

 IPR:                 Initial pain reaction

Hr:                   Hour(s)

* Kay J H and Calandra J C (1962)

 

Table 4. Individual Total Scores and Group Mean Scores for Ocular Irritation Calculated from the Draize Scores

Rabbit Number and Sex	* Individual Total Scores At:
	1 Hour	24 Hours	48 Hours	72 Hours
Male #1	4	2	0	0
Male #2	6	2	2	0
Male #3	6	2	2	0
* Group Total	16	6	4	0
* Group Mean Score	5.33	2.00	1.33	0.00

 *: Kay J H and Calandra J C (1962)

 

Table 5. Individual Fluorescein Staining

Rabbit Number and Sex	Fluorescein Staining
	24 Hours Prior to Instillation	24 Hours After Instillation	48 Hours After Instillation	72 Hours After Instillation
Male #1	-	-	-	-
Male #2	-	-	-	-
Male #3	-	-	-	-

- : Absence of Fluorescein Stain

 

Table 6. Individual Bodyweights and Bodyweight Change

Rabbit Number and Sex	Individual Bodyweight (g)		Bodyweight Change (g)
	Before treatment	End of experiment
Male #1	3328	3389	61
Male #2	3251	3307	56
Male #3	3110	3176	66

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was graded as a mild irritant (Class 4 on a 1 to 8 scale) to the rabbit eye according to the modified Kay and Calandra classification system.

Executive summary:

In an OECD TG 405 primary eye irritation study, performed under GLP, 0.1 g of the test item was instilled into the conjunctival sac of the left eye of each of 3 adult male New Zealand White rabbits. The untreated right eyes served as the control. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours after test material instillation. Observations with fluorescein staining were made approximately 24 hours before treatment and then 24, 48 and 72 hours after treatment.

No mortality occurred during the study. An Initial Pain Reaction (IPR) score of 2 was observed in all animals.

The average cornea opacity, iris and chemosis score of all three animals over 24, 48 and 72 hours was 0. The average conjunctivae score of animal #1 at 24 h was 0.33 (redness), fully reversible within 48 h. The average conjunctivae score of animal #2 and #3 at 48 h was 0.67 (redness), fully reversible within 72h. 

Fluorescein staining was negative in all animals at all time points. As all signs of eye irritation had fully reversed, the study was terminated after a period of 72 hours observation. No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred.

The test item was graded as a mild irritant (Class 4 on a 1 to 8 scale) to the rabbit eye according to the modified Kay and Calandra classification system.

Under the condition of this study and according to GHS criteria, the test substance was considered not to be irritating to the eyes of rabbits.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

All available data was assessed and the studies representing the worst-case effects were included as key studies. Other studies are included as supporting information. The in vitro data requirements were waived based on the availability of adequate in vivo data. Dosing with the test material in rabbits did not result in any signs of skin or eye irritation. The key studies are considered to be worst-case and were selected for the CSA.

 

Skin irritation
Two in vivo skin irritation/corrosion studies in rabbits are available. The key study was performed according to OECD TG 404 under GLP (Petus 2012). Three young adult male New Zealand White rabbits were treated by topical, semi-occlusive application of 0.5 g test material to their intact shaved. The test material was moistened with water to ensure good skin contact. The duration of treatment was 4 hours. The scoring of skin reactions was performed at 1, 24, 48 and 72 hours after removal of the dressing using the Draize scoring scheme. In addition, the primary irritation index (P.I.I.) was calculated.
The mean average erythema and oedema scores of all animals over 24, 48 and 72 hours were 0. The P.I.I was 0. No local dermal signs were observed in the treated animals throughout the study. No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred. As no clinical signs were observed up to 72 hours after patch removal, the study was terminated after the 72 hour observation. The body weights of all rabbits were considered to be within the normal range of variability.
The application of the test material did not result in any signs of skin irritation.

The other study was also performed according to OECD TG 404 under GLP (Seifert 1983). In this study, semi-occlusive application of the test item resulted in signs of slight irritation with a clear tendency of recovery towards the end of the observational period.

Because the test item did not show treatment related skin irritation and no local reactions in two acute dermal toxicity studies (Petus 2013; Kobel 1983) in rats, in two dermal repeated dose toxicity studies (Robertson 2013; Schoch 1986) in rats and rabbits respectively and in the skin irritation key study (Petus 2012), it can be concluded that the test item does not meet the GSH criteria for classification.

Eye irritation
Three in vivo eye irritation/corrosion studies in rabbits are available. The key study was performed according to OECD TG 405 under GLP (Török 2012). The test material was administered as an installation of a single dose of 0.1 g into the conjunctival sac of the left eye of 3 adult male New Zealand White rabbits. The untreated right eye served as the control. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours after test material installation in all animals. Observations with fluorescein staining were made approximately 24 hours before treatment and then 24, 48 and 72 hours after the treatment in all animals. Results obtained from these three animals were used to classify the test item for irritation potential. Initial Pain Reaction (IPR) of 2 was observed in all animals. The average cornea opacity, iris and chemosis score of all three animals over 24, 48 and 72 hours was 0. The average conjunctivae score of animal #1 at 24 h was 0.33 (redness), fully reversible within 48 h. The average conjunctivae score of animal #2 and #3 at 48 h was 0.67 (redness), fully reversible within 72h. Fluorescein staining was negative in all animals at all time points. As all signs of eye irritation had fully reversed, the study was terminated after a period of 72 hours observation. No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred. No mortality occurred during the study. The body weights of all rabbits were considered to be within the normal range of variability. The application of the test material did not result in signs of eye irritation. The severity of these effects were not sufficient for classification and therefore the test substance was considered to be not irritating to the eye.

The other two studies were also conducted in rabbits. One study was performed according to OECD TG 405 under GLP (Selfert 1983) and showed mean scoring of irritation effects of all three animals over 24, 48 and 72 hours of 0 and therefore, the test item was considered non-irritant and not corrosive to the eye. The second study (Maedgen 1986), showed minor effects, reversible within 7 days. Therefore, the test substance was not considered to be irritating to the eye

Respiratory irritation
In the acute inhalation toxicity studies there were no indication of respiratory irritation observed in either clinical signs or at necropsy.

Justification for classification or non-classification

Based on the available information, classification for skin and eye irritation is not warranted in accordance with EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation No. (EC) 1272/2008.