Propane-1-thiol

Endpoint summary

Description of key information

One key skin irritation study (equivalent to OECD 404) and one key eye irritation study were identified for propane-1-thiol.  

In the key skin irritation study, conducted according to a protocol similar to OECD 404 Test Guideline and in compliance with GLP, the test substance was concluded to be not irritating to skin (Moon, 1981).

In the key eye irritation study, conducted according to a protocol similar to OECD 405 Test Guideline and in compliance with GLP, the test substance was concluded to be not irritating to eyes (Moon, 1981b).

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:

1981-01-06 to 1981-02-13

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

This study is classified as reliable with restrictions because it was conducted in accordance to GLP and was reviewed by Quality Assurance. There were no deviations from protocol.

Qualifier:

according to guideline

Guideline:

other: UBTL test protocol NO. 02-50

Deviations:

no

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: University of Utah vivarium
- Housing: housed individually in galvanized steel rabbit cage with screen floors and pans
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/- 3
- Humidity (%): 30 to 60
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Type of coverage:

occlusive

Preparation of test site:

abraded

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

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

Duration of treatment / exposure:

24 hours

Observation period:

7 days

Number of animals:

6 New Zealand albino rabbits

Details on study design:

TEST SITE
- Type of wrap if used: gauze patch

REMOVAL OF TEST SUBSTANCE
- Washing (if done): lightly sponged
-Test substance was removed after 24 hours
- Time after start of exposure: 7 days


SCORING SYSTEM: Draize technique

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24/48/72 h

Score:

0.2

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

erythema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0.8

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

erythema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Reversibility:

fully reversible within: 7 days

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #4

Time point:

24/48/72 h

Score:

0

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0.8

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritation parameter:

edema score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0.5

Max. score:

4

Remarks on result:

no indication of irritation

Remarks:

No score reported at 48 hours.

Irritant / corrosive response data:

Three of six animals treated with propane-1-thiol sample exhibited very slight erythema on both abraded and unabraded sites at 25 hours post dosing. The other 3 animals appeared normal. Animals were not scored for irritatation at 48 hours after dosing. At 72 hours post dosing, 1 animal had very slight erythema on the abraded site only. All other animals had either returned to normal or remained normal. On day 7, no erythema and/or oedema was observed in any animal.

Animal Number	627	628	646	614	615	616	Ave.	Range
Observation, prescreen	0	0	0	0	0	0	0	0
25 hour	1	0	0	0	1	1	0.5	0-1
72 hour	0	0	0	0	0.5	0	0.1	0-0.5
7 day	0	0	0	0	0	0	0	0
Combined 25 & 72 hour	0.5	0	0	0	0.8	0.5	0.3	0-0.8
Combined 25 & 72 hour and 7 day	0.3	0	0	0	0.5	0.3	0.2	0-0.5

Interpretation of results:

GHS criteria not met

Conclusions:

Propane-1-thiol was slightly irritating to 3 out of 6 rabbits. Results were scored at 25 and 72 hrs and 7 days post exposure using the Primary Skin Irritation Test. The mean Draize score of 0.2 was tabulated from the 6 rabbits at these 3 observation periods.

Executive summary:

In a primary dermal irritation study, intact and abraded skin of 6 young adult New Zealand albino rabbits was exposed to 0.5 mL of propane-1 -thiol for 24 hours to 1 square inch of abraded skin. Animals were then observed for 7 days. Irritation was scored by the method of Draize primary skin irritation test.

 

Propane-1-thiol was slightly irritating to 3 out of 6 rabbits; slight erythema was reported on both abraded and intact sites in 3 animals at 25 hours post dosing. The other 3 animals appeared normal. At 72 hours after dosing, 1 animal had slight erythema on the abraded site only. All other animals had either returned to normal or remained normal. On day 7, erythema and/or oedema was not observed in any animal. In this study, propane-1 -thiol is slightly irritating to the skin based on the Draize primary skin irritation test.

 

This study received a Klimisch score of 1 and is classified as reliable with restrictions because it was conducted in accordance to GLP and was reviewed by Quality Assurance. There were no deviations from protocol.

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:

1980-12-19 to 1981-01-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

The study is classified as reliable with restrictions because it complies with GLP and adheres to OECD guideline 405.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Principles of method if other than guideline:

Method: other: UBTL Protocol No. 01A-50
Similar to OECD 405 and OPPTS 870.2400

GLP compliance:

yes

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: University of Utah vivarium or other reputable breeder
- Housing: housed individually in wire cages with no sawdust or other dust producing material in the room.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 70 +/- 3
- Humidity (%): 30 to 60
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 hr / 12 hr

Controls:

yes, concurrent no treatment

Amount / concentration applied:

Amount applied: 0.1 ml

Duration of treatment / exposure:

4 seconds

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

6

Details on study design:

Comment: not rinsed
SCORING SYSTEM: Draize

TOOL USED TO ASSESS SCORE: hand-held ophthalmoscope adn then with fluorescein

Irritation parameter:

overall irritation score

Remarks:

Draize system

Basis:

mean

Time point:

other: 1 hr.

Score:

8.3

Max. score:

14

Reversibility:

fully reversible

Irritation parameter:

overall irritation score

Remarks:

Mean Draize score

Basis:

mean

Time point:

other: 24 hrs.

Score:

2

Max. score:

6

Reversibility:

fully reversible

Irritation parameter:

overall irritation score

Remarks:

Mean Draize score

Basis:

mean

Time point:

other: 48 hrs., 72 hrs.

Score:

4.3

Max. score:

24

Reversibility:

fully reversible

Irritation parameter:

overall irritation score

Remarks:

Mean Draize score

Basis:

mean

Time point:

other: 7 day

Score:

0

Max. score:

0

Reversibility:

fully reversible

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period. Therefore, it can be concluded that the test substance is Cat 2 eye irritant. Average maximum score 6 per endpoint.

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

cornea opacity score

Basis:

animal #4

Time point:

24/48/72 h

Score:

4.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

cornea opacity score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

cornea opacity score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #4

Time point:

24/48/72 h

Score:

4.5

Max. score:

6

Reversibility:

fully reversible within:

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

iris score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #4

Time point:

24/48/72 h

Score:

4.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

conjunctivae score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0.33

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #4

Time point:

24/48/72 h

Score:

4.5

Max. score:

6

Reversibility:

fully reversible within: 7 days

Remarks on result:

positive indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #5

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

Irritation parameter:

chemosis score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0

Max. score:

6

Remarks on result:

no indication of irritation

Remarks:

Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Eye irritation was observed in 3 out of 6 animals. All eyes appeared normal by day 7 of the observation period.

The star (*) indicates the observation of a lesion

Summary of Individual Scores

	Score								Number of Animals with Eye Response
	Unwashed						Total
Animal Number	562	563	564	569	570	590	Ave.	Range
Observation, Prescreen	0	0	0	0	0	0	0	0	0
1 hour	4	4	14	10*	6	12*	8.3	4-12	6
24 hour	0	2	4	6*	0	0	2.0	0-6	3
48 hour	0	2	0	24*	0	0	4.3	0-24	2
72 hour	0	2	0	24*	0	0	4.3	0-24	2
4 day	0	2	0	2*	0	0	0.7	0-2	2
7 day	0	0	0	0	0	0	0	0	0
Combined average	0.7	2.0	3.0	11.0	1.0	2.0	3.3	0.7-11

Interpretation of results:

GHS criteria not met

Conclusions:

In this study, propane-1-thiol is an eye irritant in 3 out of 6 animals. All effects were fully reversible by day 7.

Executive summary:

In a primary eye irritation study, 0.1 millilitres of propane-1-thiol was placed on the everted lower lid of the right eye of six New Zealand white albino rabbits for seconds and then released.  The left eye remained untreated and served as a control. Eyes were not washed after exposure. Animals were observed for 7 days post dosing.  Irritation was scored by the method of Draize.

 

Ocular irritation was observed in all of the test animals following exposure (mean irritation score = 8.3, 2.0, 4.3, and 4.3 for 1, 24, 48, and 72 hours respectively). All signs of irritation dissipated at the end of the 7 day observation period.  The combined weight gain from day of dosing to day 7 was approximately 83 grams. In this study, propane-1-thiol is considered irritating to the eye based on the Draize method.

 

This study received a Klimisch score of 2 and is classified as reliable with restrictions because it complies with GLP and adheres closely to OECD guideline 405.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

One key skin irritation study that assessed the dermal irritation potential of propane-1-thiol was identified. In the study (Moon, 1981), 6 rabbits were exposed to 0.5 millilitres of propane-1-thiol on abraded and un-abraded patches of skin, using occlusive coverage. Animals were observed at 1, 24, 48, 72 hours and 7 days post exposure, yet animals were not scored at 48 hours after exposure. Irritation was scored by the method of Draize. Three of the six treated animals exhibited very slight erythema on both abraded and unabraded sites at 25 hours post dosing, while the other three appeared normal. On day 7 no erythema and/ or oedema was observed in any animal. When dermally exposed for 24 hours the mean overall irritation score (24 and 72 hours) was 0.3.

There are two additional skin irritation studies which support the findings of the key study (Latven, 1958 & Pharmachology Research, 1976). These data suggest that propane-1-thiol produces slight to no dermal irritant effects in animal studies.

In the key eye irritation study (Moon, 1981b), 0.1 millilitres of propane-1-thiol was instilled into the conjunctival sac of the right eye of 6 young adult New Zealand white rabbits (male) for 4 seconds. The eyes were not washed subsequent to exposure and the left eyes served as control. Animals were observed for a period of 7 days post exposure and eye irritation was scored by the method of Draize. Ocular irritation was observed in all of the test animals following exposure (mean irritation score = 8.3, 2.0, 4.3, and 4.3 for 1, 24, 48, and 72 hours respectively). All signs of irritation dissipated at the end of the 7-day observation period.  The combined weight gain from day of dosing to day 7 was approximately 83 grams. At the study termination, the eyes of all animals appeared normal. Propane-1thiol was considered to be irritating to the eyes of rabbits. However, total irritation scores of 0 at 24, 48 and 72 hours were recorded for three out of the six animals tested, therefore the results do not meet the criteria for classification of propane-1-thiol as an eye irritant.

In a supporting eye irritation study (Moon, 1981a), 0.1 millilitres of propane-1-thiol was instilled into the conjunctival sac of the right eye of 6 young adult New Zealand white rabbits for 4 seconds, followed by washing with 40 millilitres of saline.  The left eye of each treated animal served as the control and the animals were observed for 7 days post exposure. Ocular irritation was observed in all rabbits tested and the mean irritation score (24, 48, and 72 hours) was reported to be 1.8. Clinical signs of irritation observed one-hour post exposure were secreted discharge, swollen eyes, and chemosis. Most observed signs of irritation were reversible in the first 24 hours post exposure and all signs of irritation were reversible 7 days after exposure. Propane-1-thiol was considered to be moderately irritating to the eyes of rabbits. Only total eye irritation scores were reported for individual animals from observations at 24/48/72 hours. Although eye irritation was recorded in 6 out of 6 animals at 24 hours (average total irritation score 2.3), five of the six animals had irritation scores of 0 at 48 and 72 hours, therefore it is concluded that the substance is not irritating to the eye. All eyes appeared normal by day 7 of the observation period.

There are three additional low reliability eye irritation studies which report mild irritant effects in the test animals and support the findings of the key study (Latven, 1958; Unknown author; Fairchild, 1958; Moon, 1981a).

In a supporting in vitro eye irritation study (Charles River Laboratories, 2022, reliability score 1), the eye hazard potential of n-propyl mercaptan (propane-1-thiol) was measured by its ability to induce opacity and increase permeability in isolated bovine corneas. The study used the Bovine Corneal Opacity and Permeability (BCOP) method according to OECD Test Guideline 437 and in compliance with GLP. An undiluted 750 μL application of the clear, colourless liquid n-propyl mercaptan (Batch 21EPNPS05) was made to the prepared corneas for 10 ± 1 minutes exposure time. The negative control responses for opacity and permeability were less than the upper limits of the laboratory historical range indicating that the negative control did not induce irritancy on the corneas. The mean in vitro irritancy score (IVIS) of the positive control (ethanol) was 55 and was within two standard deviations of the current historical positive control mean. It was therefore concluded that the test conditions were adequate and that the test system functioned properly. N-propyl mercaptan induced ocular irritation resulting in a mean IVIS of 43 after treatment. Since the IVIS falls between the range >3 - ≤55, no prediction on the classification can be made according to Regulation (EC) No. 1272/2008.

Justification for classification or non-classification

Based on the available data for propane-1-thiol, no classification for skin irritation and eye irritation is required according to Regulation (EC) No 1272/2008.