Thiram

Endpoint summary

Description of key information

key, skin irritation (rabbit, EPA OPP 81-5): not irritating

key, skin irritation (rabbit, 21 day, OECD 410): irritating

key, eye irritation (rabbit, EPA OPP 81-4): irritating

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:

29 Apr - 2 May 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

adopted in 2002

Deviations:

yes

Remarks:

individual body weight at study termination was not reported

Qualifier:

according to guideline

Guideline:

EPA OPP 81-5 (Acute Dermal Irritation)

Version / remarks:

adopted 1984

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Broekman Instituut, Someren, The Netherlands
- Age at study initiation: ca. 18-19 weeks
- Weight at study initiation: not reported
- Housing: individually in "Lurane" plastic cages
- Diet: pelleted standard laboratory diet (Hope Farms, Woerden), 100 g per day and animal
- Water : tap water, ad libitum
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 -21
- Humidity (%): 45 - 60
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 29 Apr 1985 To: 2 May 1985

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

water

Controls:

other: Untreated flanks were used as controls.

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 0.5 g of test substance was moistened with 0.5 mL of distilled water immediately before dosing.


NEGATIVE CONTROL
- Amount(s) applied (volume or weight): the right flank was covered without test substance as a negative control.

POSITIVE CONTROL: No positive control substance was applied. No positive control data was provided.

Duration of treatment / exposure:

4 h

Observation period:

72 h

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: Approximately 10 cm² of the central back of the animals was clipped one day before treatment. The test substance was evenly spread on a patch of 6 cm² and applied to the left flank of each animal.
- Type of wrap if used: metalline wound dressing, attached to tape (Micropore) and wrapped in flexible bandage (Coban).


REMOVAL OF TEST SUBSTANCE
- Washing: tissue moistened with tap water
- Time after start of exposure: 4 h

OBSERVATION TIME POINTS
Exposed skin sites were examined for signs of erythema and oedema and the responses were scored at 30-60 minutes, and approximately 24, 48 and 72 hours after patch removal. For reference the control site on the contra lateral flank was used. Examination time points: 0.5-1, 24, 48, 72 h after removal of the test patch.

SCORING SYSTEM:
- Method of calculation: According to Draize scoring system

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

Edema 0-4:
0: No oedema, 1: very slight oedema (barely perceptible), 2: well-defined oedema (edges of area well-defined by definite raising), 3: moderate to severe oedema (raised approximately 1mm), 4: severe oedema (raised more than 1 mm extending beyond the area of exposure)

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.33

Max. score:

4

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: 1 h and 24 h after patch removal, erythema of grade 1 were observed which were fully reversible at the 48 h reading time point.

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal 2 - 6

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility not applicable

Irritant / corrosive response data:

1/6 animals showed erythema (scored with grade 1) at the 1 h and 24 h observation time point. No skin reaction was seen in this animals thereafter or in any other animal for any time point.

Summarized results can be found in Attachment 1 in the attached background material.

Interpretation of results:

other: According to the classification criteria of the CLP Regulation (EU) No. 1272/2008, no classification is required.

Conclusions:

The study is in accordance with EPA OPP 81-5 (Acute Dermal Irritation) and GLP.
Under the conditions chosen, a single semi-occlusive application of the test substance to intact rabbit skin for 4 h elicited no dermal irritation. Overall, except of very slight erythema (score 1) observed in one animal persistent for 24 hours, no signs of dermal irritation including erythema and oedema were noted in the other treated animals. No other adverse effects to the treatment have been noted. According to criteria of the CLP Regulation (EU) No. 1272/2008, no classification of the test item for skin irritation is required.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (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:

16 Apr - 1 May 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

adopted in 2021

Deviations:

yes

Remarks:

methodological limitations (e.g. individual body weight at study termination was not reported, no anesthetic/analgesic pretreatment performed)

Qualifier:

according to guideline

Guideline:

EPA OPP 81-4 (Acute Eye Irritation)

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Cpb/TNO, Zeist, The Netherlands
- Age at study initiation: adult, not further specified
- Weight at study initiation: 3591 - 3567 g (4 days before administration of the test susbtance)
- Housing: individually in metal cages with perforated floors
- Diet: standard laboratory diet (Hope Farms, Woerden), pelleted diameter 4 mm, 100 g per animal and day
- Water: tap water, ad libitum
- Acclimation period: at least 12 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 21
- Humidity (%): 45 - 65
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 16 Apr 1985 To: 1 May 1985

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 30 g per animal

Duration of treatment / exposure:

eyes were not rinsed

Observation period (in vivo):

15 days

Observations were performed immediatly after instillation of the test substance, and approximatly 1, 24, 48 and 72 h and 7 and 15 days after instillation of the test substance.

Number of animals or in vitro replicates:

6 females

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing: none

SCORING SYSTEM:
Grades of ocular lesions: Cornea

Degree of Opacity 0 – 4 (0 = no finding, 1 = slight, disperse, diffuse opacity, 2 = extensive, diffuse opacity, iris blurred, 3 = nacreous areas, no details of iris visible, size of pupil hardly discernible, 4 = opaque cornea, iris not discernible through the opacity)

Iris 0 – 2 (0 = no finding, 1 = swelling, reddening, positive light reaction, 2 = severe reddening and swelling, no light reaction)

Conjunctivae

Redness 0 – 3 (0 = blood vessels normal, 1 = vessels abnormally filled, 2 = diffuse reddening, 3 = diffuse deep reddening)

Chemosis 0 – 4 (0 = no swelling, 1 = slight swelling,  2 =severe swelling, lids everted, 3 = lids cover one half of eye, 4 = lids cover more than half eye, necroses and ulcers on the conjunctivas)

Directly after instillation, 1 h, 24 h, 48 h, 72 h, 7 d, 15 d

Approximately 24 hours after instillation of the test substance (immediately after scoring the cornea/opacity), a solution of 2% fluorescein in water was applied to both eyes of each animal to examine quantitatively the potential for corneal injury. The brightly green staining area indicating epithelial damage was estimated as a percentage of the total corneal area. Any observed local effects were noted.

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

2.1

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

2.2

Max. score:

3

Reversibility:

fully reversible within: 15 days

Irritation parameter:

iris score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

0.2

Max. score:

2

Reversibility:

fully reversible within: 15 days

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #3

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #4

Time point:

24/48/72 h

Score:

2.7

Max. score:

3

Reversibility:

not fully reversible within: 7days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #5

Time point:

24/48/72 h

Score:

1.3

Max. score:

3

Reversibility:

fully reversible within: 7 days

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #6

Time point:

24/48/72 h

Score:

3

Max. score:

3

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2.7

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #4

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #5

Time point:

24/48/72 h

Score:

1.3

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

chemosis score

Basis:

animal #6

Time point:

24/48/72 h

Score:

2.3

Max. score:

4

Reversibility:

fully reversible within: 15 days

Irritation parameter:

iris score

Basis:

other: animal 1, 4, 5 and 6

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: not applicable

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.7

Max. score:

2

Reversibility:

other: 7 days

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.7

Max. score:

2

Reversibility:

other: 15 days

Irritant / corrosive response data:

The summarized results can be found in Table 1 and Attachment 1 in the attached background material

Other effects:

To calculate the mean, the scores from time points 24, 48 and 72 h after instillation of the test substance were used. The other observation points were ignored or used only to assess the reversibility of the effects.

There was no indication of a systemic effect of treatment.

Table 1. Results of eye irritation study.
Rabbit #	Time [h]	conjunctivae		iris	cornea
		redness	swelling
1	1	1	3	0	0
	24	1	2	0	0
	48	3	2	0	0
	72	2	1	0	0
	average	2,0	1,7	0,0	0,0
2	1	1	2	0	0
	24	1	3	0	0
	48	3	3	1	0
	72	2	2	1	0
	average	2,0	2,7	0,7	0,0
3	1	2	3	0	0
	24	2	3	0	0
	48	2	2	1	0
	72	2	2	1	0
	average	2,0	2,3	0,7	0,0
4	1	2	3	0	0
	24	3	2	0	0
	48	3	2	0	0
	72	2	2	0	0
	average	2,7	2,0	0,0	0,0
5	1	1	3	0	0
	24	1	2	0	0
	48	2	1	0	0
	72	1	1	0	0
	average	1,3	1,3	0,0	0,0
6	1	2	2	0	0
	24	3	2	0	0
	48	3	3	0	0
	72	3	2	0	0
	average	3,0	2,3	0,0	0,0
	Time [h]	conjunctivae		iris	cornea
		redness	swelling
average score	1	1,50	2,67	0,00	0,00
	24	1,83	2,33	0,00	0,00
	48	2,67	2,17	0,33	0,00
	72	2,00	1,67	0,33	0,00
	24+48+ 72	2,17	2,06	0,22	0,00

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The study is in accordance with EPA OPP 81-4 (Acute Eye Irritation) and GLP. Under the conditions chosen, instillation of the test substance into the eyes of 6 female rabbits elicited a positive response. According to the classification criteria of the CLP Regulation (EU) No. 1272/2008, classification for eye Irritation Category 2 (H319) is warranted.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Effects on skin irritation:

In a GLP-compliant study conducted according to EPA OPP 81-5 and similar to OECD 404, the test substance showed no skin irritating potential in female rabbits (Report number: 0113/173). No edema was observed after exposure of 6 rabbits to 0.5 g of the test substance applied to intact skin and covered with a semi-occlusive for 4 h. 1/6 animals showed an erythema scored with grade 1 at the 1 h and 24 h observation time point. No skin reaction was seen in this animal thereafter. No skin reactions were further observed in any other animal for any time point.

However, in a 21-day percutaneous study performed in rabbits (Report number: UCB 421/920767) conducted according to OECD 410 and under GLP conditions, the test substance caused dermal irritation at all dose levels when applied dermally for three weeks to the intact skin of male and female rabbits (100, 300 and 1000 mg/kg bw/day). Briefly, slight or well-defined erythema with or without slight or well-defined oedema were observed in rabbits of all dose groups, with the intensity and frequency being dose-dependent. The incidence of reactions was initially low at Day 7 but increased over the following two weeks and affected the majority of the rabbits. These reactions were frequently accompanied by a residual (brown) staining from the test substance and/or desquamation of the stratum corneum. Based on the observed local effects in the available short-term dermal repeated dose toxicity study (UCB 421/920767) and on human experience, the test substance is included in Annex VI of Regulation (EC) No 1272/2008 as “irritating to skin”, and is classified as skin irritating category 2, H315.

 

 

 

Effects on eye irritation:

A GLP-conform eye irritation/corrosion study was performed according to EPA OPP 81-4 and similar to OECD 405 to evaluate the eye irritancy potential of the test substance (Report number: 0113/174). A single dose of 30 mg test substance was instilled to the left eyes of 6 female rabbits, the right eye served as a control. The observation period was 15 days after instillation of the test item. There was no indication of a systemic effect of the treatment with the test substance. Within 1 hour after instillation of thiram substantial chemosis (score 2 – 3) and redness (score 1 – 2) of the conjunctivae were observed in all animals. The individual mean irritation scores (24 – 72 hours) of the rabbits were 0.00 for all animals for corneal opacity, 0.00, 0.67, 0.67, 0.00, 0.00, 0.00 for effects on the iris, 2.00, 2.00, 2.00, 2.67, 1.33 and 3.00 for conjunctival redness and 1.67, 2.67, 2.33, 2.0, 1.33 and 2.33 for conjunctival chemosis. These effects were fully reversible within 15 days.

According to the classification criteria of the CLP Regulation (EU) No. 1272/2008, classification for eye irritation category 2 (H319) is warranted.

Justification for classification or non-classification

The available data on skin irritation of the test substance do not meet the criteria for classification according to Regulation (EC) 1272/2008 and are therefore conclusive but not sufficient for classification.

However, based on local effects observed in a dermal 21-d repeated dose toxicity study in rabbits (UCB 421/920767) and human experience, the test substance is included in Annex VI of Regulation (EC) No 1272/2008 as “irritating to skin”. The test substance and is classified as skin irritating category 2 with the hazard statement H315.

Based on the available data on eye irritation of the test substance and according to the classification criteria of the CLP Regulation (EU) No. 1272/2008, classification for eye irritation category 2 (H319) is warranted.

The classification in regard to irritation is in line with the harmonised classification of the test substance (Annex VI of Regulation (EC) 1272/2008, index number 006-005-00-4).