A mixture of isomers of branched tetracosane

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 November 1994 and 5 November 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The work described was performed in compliance with the UK Principles of Good Laboratory Practice (The united Kingdom Compliance Programme. Department of Health 1989)

Test material

Test material information

Constituent 1

Reference substance name:

A mixture of isomers of branched tetracosane

EC Number:

417-060-2

EC Name:

A mixture of isomers of branched tetracosane

Cas Number:

151006-61-0

Molecular formula:

C24 H50

IUPAC Name:

A mixture of isomers of branched tetracosane

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rabbits were supplied by David Percival Ltd. Moston. Sandbach. Cheshire. UK.
- Age at study initiation: Twelve to twenty weeks old
- Weight at study initiation: Animals weighed 2.23 to 2.51kg and were approximately twelve to twenty weeeks old.
- Housing:Animals were individually housed in suspended metal cages.
- Diet (e.g. ad libitum): Free access to mains drinking water and food (STANRAB SQC Rabbit Diet. Special Diets Services Ltd. Witham. Essex. UK) was allowed throughout the study.
- Water (e.g. ad libitum):Free access to mains drinking water and food (STANRAB SQC Rabbit Diet. Special Diets Services Ltd. Witham. Essex. UK) was allowed throughout the study.
- Acclimation period: Seven days.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Animal room maintained a temperature of 17 to 20°C.
- Humidity (%): 58 to 65%
- Air changes (per hr): Rate of air exchange was approximately 15 changes per hour
- Photoperiod (hrs dark / hrs light):Lighting controlled by a time switch to give 12 hours continuous light and 12 hours darkness.


IN-LIFE DATES: From: Day 0 To: Day 3

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: A contralateral area of untreated skin was identified on each rabbit to serve as the control against which the reactions of the untreated site were evaluated.

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): A quantity of 0.5ml of the test material was introduced under a 2.5cm x 2.5cm cotton gauze patch.
- Concentration (if solution):No Data


VEHICLE
- Amount(s) applied (volume or weight with unit):Not applicable
- Concentration (if solution):Not applicable
- Lot/batch no. (if required): Not applicable
- Purity:Not applicable

Duration of treatment / exposure:

4 Hours

Observation period:

Thirty minutes following the removal of the patches and approximately 24, 48 and 72 hours after patch removal, the test sites were examined for evidence of primary irritation and scored.

Number of animals:

6 Rabbits

Details on study design:

TEST SITE
- Area of exposure: The back of each rabbit.
- % coverage: 2.5cm by 2.5cm cotton gauze patch.
- Type of wrap if used: 2.5cm by 2.5cm cotton gauze patch and placed in position with a strip of porous tape ( Micropore surgical tape, 3M Health care, Loughborough, England)


REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test material was removed by gentle swabbing with cotton wool soaked in 74% Industrial Methylated Spirits. The control sites were similarly swabbed.
- Time after start of exposure: 4 hours.


SCORING SYSTEM:
EVALUATION OF SKIN REACTIONS
Erythema and Eschar Formation
Value
No erythema.............................................................................0
Very slight erythema (barely perceptible)........................... 1
Well-defined erythema.............................................................2
Moderate to severe erythema.................................................3
Severe erythema (beef redness) to eschar formation preventing grading of erythema...4
 

Oedema Formation
Value
No oedema..................................................0
Very slight oedema (barely perceptible).......................1
Slight oedema (edges of area well-defined by definite raising)..................2
Moderate oedema (raised approximately 1 millimetre)................................3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure)...........4

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 72h

Score:

0.25

Reversibility:

no data

Remarks on result:

other: No corrosive effects were noted.

Results 2

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 72h

Score:

0.1

Reversibility:

no data

Results 3

Irritation parameter:

edema score

Basis:

mean

Score:

0

Reversibility:

no data

Irritant / corrosive response data:

Please see attached tables 1-3.

Other effects:

Not applicable.

Any other information on results incl. tables

EVALUATION OF SKIN REACTIONS
Erythema and Eschar Formation	Value
No erythema....................................................................................................................	0
Very slight erythema (barely perceptible)..........................................................................	1
Well-defined erythema.....................................................................................................	2
Moderate to severe erythema...........................................................................................	3
Severe erythema (beef redness) to eschar formation preventing grading of erythema..........	4

 

Oedema Formation	Value
No oedema.....................................................................................................................	0
Very slight oedema (barely perceptible)............................................................................	1
Slight oedema (edges of area well-defined by definite raising)............................................	2
Moderate oedema (raised approximately 1 millimetre)......................................................	3
Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure).......................................................................................................................................	4

Any other skin reactions, if present, were also recorded.

Calculation of Primary Irritation Index. (FIFRA Data Reporting Guidelines)

The values for erythema and oedema for each animal at the 30 minute, 24, 48 and 72 -hour readings were totalled for the six test rabbits and each total was divided by 4 to give a score for each animal. The total of these scores was divided by 6 to give the primary irritation index of the test material.

Calculation of scores according to Annex VI of Council Directive 67/548/EEC. Relating to the classification, Packaging and Labelling of Dangerous Substances.

The values for erythema and oedema for each animal at the 24, 48 and 72 hour readings were totalled for the six test animals and the total scores divided by 18 to give a mean value for erythema and a mean value for oedema.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test material. Alkane 2. produced a primary irritation index of 0.25 calculated according to FIFRA data reporting guidelines. No corrosive effects were noted. The test material produced mean scores of 0.1 for erythema/eschar formation and 0.0 for oedema according to EC labelling regulations.

Executive summary:

A study was performed to assess the irritancy potential of the test material to the skin of the New Zealand White rabbit.

The study was designed to comply with the requirements of the U.S. Environmental Protection Agency (EPA) Guidelines, the OECD Guidelines for testing of chemicals No.404 "Acute Dermal Irritation/ Corrosion" .

The results may be used as a basis for classification and labelling under Annex VI of Council Directive 67/548/EEC (as adapted to technical progress by commission Directive 93/21/EEC).

A single 4 -hour, semi-occluded application of the test material to the intact skin of six rabbits produced very slight erythema at four treated skin sites 30 minutes after patch removal. Very slight erythema persisted at two treated skin sites at the 24 -hour observation. All treated skin sites appeared normal at the 48 -hour observation.

The test material produced mean scores of 0.1 for erythema/eschar formation and 0.0 for oedema according to EC labelling regulations.