N,N-dimethyl-p-toluidine

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N, N-dimethyl-p-toluidine

IUPAC Name:

N, N-dimethyl-p-toluidine

Constituent 2

Reference substance name:

N,N-dimethyl-p-toluidine

EC Number:

202-805-4

EC Name:

N,N-dimethyl-p-toluidine

Cas Number:

99-97-8

Molecular formula:

C9H13N

IUPAC Name:

N,N,4-trimethylaniline

Details on test material:

- Name of test material: N,N-dimethyl-p-toluidine
- Molecular formula: C9H13N
- Substance type: Organic
- Batch number/ Lot no.: 18
- Storage conditions : Room temperature (20 - 30 °C)
- Physical state: Liquid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Procured from GENTOX Bio services., Hyderabad, India
- Age at study initiation: 3 to 4 Months (Approximately)
- Weight at study initiation: Minimum: 1.796 kg and Maximum: 1.998 kg (Prior to Treatment)
- Housing: The animals were housed individually in stainless steel cages.
- Diet (e.g. ad libitum): All animals were provided conventional laboratory rabbit diet (Nutrivet Life Sciences, Pune) ad libitum.
- Water (e.g. ad libitum): Aqua guard filtered tap water was provided ad libitum
- Acclimation period: 5 days (Animal No.-1) and 7 days (Animal No.-2 and 3)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Minimum: 19.60 °C, Maximum: 22.30 °C
- Humidity (%): Minimum: 51.10 % , Maximum: 67.40 %
- Air changes (per hr): More than 12 changes per hour
- Photoperiod (hrs dark / hrs light): 12:12

IN-LIFE DATES: From: To:

Test system

Type of coverage:

occlusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent vehicle

Amount / concentration applied:

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

Duration of treatment / exposure:

4 hours

Observation period:

72 hours

Number of animals:

3 female rabbits

Details on study design:

TEST SITE
- Area of exposure: Approximately 24 h prior to treatment, the fur coat of each rabbit was removed from dorsal lumbar region approximately 6 X 6 cm at contralateral sites on each rabbit using clipper, one as control and other site as treatment. Rabbits with healthy intact skin were selected for the study
- % coverage: 6 X 6 cm
- Type of wrap if used: porous gauze dressing and non-irritating tape

REMOVAL OF TEST SUBSTANCE
- Washing (if done): cotton soaked in distilled water
- Time after start of exposure: 4-hour exposure period


SCORING SYSTEM:
Gradation as per draize method

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 1,2,3

Time point:

other: 24, 48 and 72 hours

Score:

0 - 1

Max. score:

3

Reversibility:

no data

Remarks on result:

other: Not irritating

Results 2

Irritation parameter:

edema score

Basis:

animal: 1,2,3

Time point:

other: 24, 48 and 72 hours

Score:

0 - 0.33

Max. score:

3

Reversibility:

no data

Remarks on result:

other: Not irritating

Irritant / corrosive response data:

The following were observed in treated rabbits.
The patch was removed after 4 hours and rabbits were observed for erythema and oedema at 1, 24, 48 and 72 hours after patch removal, evaluated and graded as per draize method.
Animal No. 1, very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observation. At 24 hour very slight erythema (barely perceptible) and no oedema was observed. At 48 and 72 hours observation no erythema and no oedema was observed in animal no 1.
Animal No. 2, revealed very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observation post patch removal. At 24 hour well defined erythema and very slight oedema (barely perceptible) was observed. At 48 hour very slight erythema (barely perceptible) and no oedema was observed. At 72 hour no erythema and no oedema was observed. Animal No. 3, revealed very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observation post patch removal. At 24 hour slight erythema (barely perceptible) and no oedema was observed. At 48 and 72 hour no erythema and no oedema was observed.
The individual mean score at 24, 48 and 72 hours for animal nos. 1, 2 and 3 were 0.33, 1.00, 0.33 and 0.00, 0.33, 0.00, for erythema and oedema formation, respectively

Other effects:

Clinical Observation
No systemic toxicity was observed at treated rabbits during the experimental period.

Mortality
No mortality was observed during the observation period.

Body Weights
Body weights were increased as compared to day 0 in all the three animals at terminal sacrifice

Any other information on results incl. tables

In Treated area Dose:0.5 ml of test item                                                              Sex:Female

 

Animal No.	Test	Treated  area*	Erythema score				Oedema score
			1h	24h	48h	72h	1h	24h	48h	72h
1	Initial	Right	1	1	0	0	1	0	0	0
2	Confirmatory	Right	1	2	1	0	1	1	0	0
3		Right	1	1	0	0	1	0	0	0

In Control area  Dose:0.5 ml of distilled water                                               Sex:Female

 

Animal No.	Test	Treated area*	Erythema score				Oedema score
			1h	24h	48h	72h	1h	24h	48h	72h
1	Initial	Left	0	0	0	0	0	0	0	0
2	Confirmatory	Left	0	0	0	0	0	0	0	0
3		Left	0	0	0	0	0	0	0	0

Key:h = Hour.

 

Erythema                                                                               Oedema

0 =No erythema                                                                  0 =No oedema

1 = Very slight erythema (barely perceptible)                       1 = Very slight oedema(barely perceptible)

2 = Well defined erythema

Mean Individual Animal Score at 24, 48 and 72 hours

 

Animal Number                   Observations	1	2	3
Erythema	0.33	1.00	0.33
Oedema	0.00	0.33	0.00

Individual Animal BodyWeight

Sex:Female

Animal No.	Body Weight (kg)
	Prior to Dosing	At termination
1	1.796	1.856
2	1.940	1.992
3	1.998	2.110

Key: kg = kilogram

Individual Animal Clinical Signs

Sex:Female

Animal No.	Days (Post dosing Observation)
	0	1	2	3
1	1	1	1	1
2	1	1	1	1
3	1	1	1	1

Key: ./. = Not Applicable. 1 = Normal.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The individual mean score at 24, 48 and 72 hours for animal nos. 1, 2 and 3 were 0.33, 1.00, 0.33 and 0.00, 0.33, 0.00, for erythema and oedema formation, respectively. Hence, under the experimental conditions tested it is concluded that N, N-dimethyl-p-toluidine was Non-Irritating to the skin of female New Zealand White rabbits and Classified as “Category- Not Classified as Skin Irritant" as pre CLP criteria

Executive summary:

Acute Dermal Irritation/corrosion Study of N, N-dimethyl-p-toluidine in Rabbits was performed as per OECD guideline No. 404. Three healthy young adult female rabbits were used. Rabbits with good intact skin were selected for the study. The hairs of all the rabbits were clipped at contralateral sites, approximately 24 hours prior to treatment.A dose of0.5 ml of test item (as such) wasappliedto the skin,over an area of approximately 6 x 6 cm clippedof haironone side of rabbits.The other untreated side was kept as control area and0.5 ml of distilled water was applied at this site. At the end of 4 hours, the gauze patch was removed and test item application site was wiped with water without altering the integrity of the epidermis. Animal No. 2, revealed very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observationpost patch removal. At 24 hour well defined erythema andvery slight oedema (barely perceptible) was observed. At 48 hour very slight erythema (barely perceptible) and no oedema was observed. At 72 hour no erythema and no oedema was observed. Animal No. 3, revealed very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observationpost patch removal. At 24 hourvery slight erythema (barely perceptible)andno oedema was observed. At 48 and 72 hour no erythema and no oedema was observed.The patch was removed after 4 hours and rabbits wereobservedfor erythema and oedemaat 1, 24, 48 and 72 hours after patch removal, evaluatedand graded as per draize method.

The individual mean score at 24, 48 and 72 hoursfor animal nos. 1, 2 and 3 were 0.33, 1.00, 0.33 and 0.00, 0.33, 0.00, for erythema and oedema formation, respectively

Initially, the test item was applied to the clipped area of skin of one rabbit. The test site was covered with gauze patch.After 4 hours of exposure in animal no. 1, very slight erythema (barely perceptible) and very slight oedema (barely perceptible) observed at 1 hour of observation. At 24 hour very slight erythema (barely perceptible) and no oedema was observed.Hence the confirmatory test was conducted after 24 hours on additional two rabbits (No. 2 and 3)to confirm the non irritant nature of the test item. At 48 and 72 hours observation no erythema and no oedema was observed in animal no 1. Hence, under the experimental conditions tested it is concluded that N, N-dimethyl-p-toluidine was Non-Irritating to the skin of female New Zealand White rabbits and Classified as “Category- Not Classified as Skin Irritant" as pre CLP criteria