4-methylthiosemicarbazide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-04-03 to 2001-04-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study (OECD 404)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

Minor deviations were not considered to have compromised the validity or integrity of the study : the relative humidity recorded in the animal room was sometimes outside of the target ranges ; the animals were given 110 pelleted

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-methylthiosemicarbazide

EC Number:

229-563-2

EC Name:

4-methylthiosemicarbazide

Cas Number:

6610-29-3

Molecular formula:

C2H7N3S

IUPAC Name:

1-amino-3-methylthiourea

Details on test material:

other name: MTSC
batch number: 00-11-001-050
Sponsor's filing number: CAL 551/01
description: white powder container: one plastic flask
date of receipt: 15 February 2001
storage conditions: at room temperature, protected from light and humidity
purity: 99.7%
expiry date: January 2002.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
-Sex: male
- Source: CEGAV (Saint Mars d'Egrenne, France)
- Age at study initiation: no data
- Weight at study initiation: 2.6 ± 0.5 kg
- Housing: individually in polystyrene cages
- Diet (e.g. ad libitum): free access to 110 pelleted diet (UAR, Villemoisson, Epinay¬sur-Orge, France).
- Water (e.g. ad libitum): Drinking water filtered by a FG Millipore membrane (0.22 micron) was provided ad libitum
- Acclimation period: at least 5 days before the beginning of the study

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 ± 3°C
- Humidity (%): 30 to 70%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped using electric clippers

Vehicle:

other: none

Controls:

not required

Amount / concentration applied:

undiluted
Purified water (prepared at CIT by reverse osmosis) was used in order to moisten the test substance and ensure a good contact with the skin.

Duration of treatment / exposure:

4 hour(s)

Observation period:

3 days (because no effect were observed at 72 hours)

Number of animals:

3

Details on study design:

ADMINISTRATION:
- Area of exposure: left flank (3-minute exposure) and right flank (4-hour exposure)
- Total quantity applied: 500 mg
- Administration frequency: once
- Removal of test substance: residual is wiped with a dry gauze pad
EXAMINATIONS:
- Scoring system: Draize's score
- Examination time points: 1h, 24 h, 48 h and 72 hours after the patch removal.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

3 rabbits

Time point:

other: 24-48-72 hours

Score:

0.1

Max. score:

4

Reversibility:

fully reversible within: 48 hours

Remarks on result:

other: Scores of 3 rabbits were: 0.3, 0.0 and 0.0

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

3 rabbits

Time point:

other: 24-48-72 hours

Score:

0

Max. score:

4

Remarks on result:

other: Scores of 3 rabbits were 0.0

Irritant / corrosive response data:

After a 3-minute exposure: No cutaneous reaction were noted in any rabbits.
After a 4-hour exposure: A very slight erythema (grade 1) was observed in one rabbit at 1h and 24h after patch removal. This erythema disappeared thereafter. Other rabbits did not exhibit any cutaneous reactions.

Other effects:

none

Any other information on results incl. tables

Table : individual cutaneous examinations and mean values of the scores recorded at each reading (24, 48 and 72 hours) for each animal (application for 4 hours)

 

Rabbit number	Dermal irritation	scores				Mean irritation score (1)
		1h (D1)	24h (D2)	48h (D3)	72h (D4)
993	Erythema	1	1	0	0	0.3
	Oedema	0	0	0	0	0.0
	Other	*	*	*	*
578	Erythema	0	0	0	0	0.0
	Oedema	0	0	0	0	0.0
	Other	*	*	*	*
993	Erythema	0	0	0	0	0.0
	Oedema	0	0	0	0	0.0
	Other	*	*	*	*

 

(1)  mean of scores on days 2, 3 and 4

* : none

D = day, h = hour

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: other: Regulation EC no.1272/2008

Conclusions:

Under these experimental conditions, the test substance MTSC is non-irritant when applied topically to rabbits.

Executive summary:

The potential of the test substance MTSC to induce skin irritation was evaluated in rabbits according to OECD 404 and in compliance with the principles of Good Laboratory Practice Regulations.

In the first instance, the test substance was applied for periods of 3 minutes and 4 hours to a single male New Zealand White rabbit. Since the test substance was not severely irritant on this first animal, it was then applied for 4 hours to two other animals. A single dose of 500 mg of the test substance in its original form was applied to the closely­clipped skin of one flank. The test substance was held in contact with the skin by means of a semi-occlusive dressing. Cutaneous reactions were observed approximately 1 hour, 24, 48 and 72 hours after removal of the dressing.

 

After a 3-minute exposure (one animal): No cutaneous reactions were observed.

After a 4-hour exposure (three animals): A very slight erythema was noted in one animal on days 1 and 2. No other cutaneous reactions were observed.

Mean scores over 24, 48 and 72 hours for each animal were 0.3, 0.0 and 0.0 for erythema and 0.0, 0.0 and 0.0 for oedema.

Under these experimental conditions, the test substance MTSC is non-irritant when applied topically to rabbits.