Reaction mass of 2-methyldecan-1-al and undecanal

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

From 26 FEB 1985 to 5 MAR 1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

: no substance composition or purity stated, no statement given concerning results for day 14 observation

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

n-undecanal

IUPAC Name:

n-undecanal

Constituent 2

Reference substance name:

2-methyl decanal

IUPAC Name:

2-methyl decanal

Constituent 3

Reference substance name:

n/i-undecanal

IUPAC Name:

n/i-undecanal

Details on test material:

- Name of test material (as cited in study report): n/i-undecanal
- Substance type: colourless
- Physical state: liquid
- Storage condition of test material: room temperature

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rosemead Rabbits Limited, Lea Valley, UK
- Age at study initiation: 12 to 16 weeks
- Weight at study initiation: 2.3 to 2.43 kg
- Housing: suspended metal cage, individually
- Diet: standard laboratory diet (Rabbit Diet, A. W. Tindall Limited, Holbeach, UK), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 +/- 2
- Humidity (%): 45-55
- Air changes (per hr): ~ 10
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipping

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

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

Duration of treatment / exposure:

4 hours

Observation period:

7 days

Number of animals:

3

Details on study design:

TEST SITE
- Area of exposure: 6.25 cm²
- Type of wrap if used: semi-occlusive


REMOVAL OF TEST SUBSTANCE
- Washing (if done): gentle swabbing with cotton wool soaked with lukewarm water
- Time after start of exposure: 4 hours


SCORING SYSTEM: according to guideline OECD 404

READING TIMES: 1, 24, 48, 72 hours after removal of the patches, if irritation persisted further observations were made 7 days and 14 days following removal of the patches

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Remarks:

: total scores for erythema and edema divided by 6

Time point:

other: 24 and 72 h

Score:

5.5

Reversibility:

no data

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

: individual scores: 3/3/2.67

Time point:

other: 24-48-72 h

Score:

ca. 2.89

Max. score:

3

Reversibility:

not fully reversible within: 7 days

Remarks on result:

other: reactions were extending beyond the site of application

Results 3

Irritation parameter:

edema score

Basis:

mean

Remarks:

: individual scores 2/3.34/3.34

Time point:

other: 24-48-72 h

Score:

ca. 2.89

Max. score:

4

Reversibility:

not fully reversible within: 7 days

Remarks on result:

other: reactions were extending beyond the site of application

Irritant / corrosive response data:

Additionally to erythema and edema desquamation was seen in two animals at 72 h. At day 7 hyperkeratinization with some flaking from affected areas was also evident in all three animals.

Any other information on results incl. tables

After patch removal:

- 1 h: very slight erythema (score 1/1/1) and very slight or slight edema (score 2/2/1), with reactions extending beyond application site

- 24 h: moderate erythema (score 3/3/3) and slight or severe edema (score 2/4/4), with reactions extending beyond application site

- 48 h: moderate erythema (score 3/3/3) and slight edema (score 2/2/2), with reactions extending beyond application site

- 72 h: well defined or moderate erythema (score 3/3/2) and slight edema (score 2/2/2), with reactions extending beyond application site and desquamation observed in 2 animals

- 7 days: very slight or well defined erythema (score 1/2/1) and very slight edema (score 1/1/1), with reactions extending beyond application site and hyperkeratinization with some flaking of affected areas in all animals

Applicant's summary and conclusion

Interpretation of results:

irritating

Remarks:

Migrated information Criteria used for interpretation of results: other: CLP Regulation

Conclusions:

Under the conditions of this study the test substance was irritating to the skin of rabbits. The proportions of n- and iso-undecanal were not provided, but read across to the registered substance can be made as detailed in the justification provided in the endpoint summary.

Executive summary:

3 New Zealand white rabbits were dermally exposed to the undiluted test substance (purity: not stated; 0.5 mL fluid were soaked into 6.25 cm² gauze patch) according to testing guideline OECD 404. After 4 h of semiocclusive exposure the test substance caused well-defined to severe erythema (mean score: 2.89) and slight or severe edema (mean score: 2.89). After 72 h two animals out of three showed desquamation, after 7 days all animals showed hyperkeratinization with some flaking from the affected areas. The test item thus revealed irritating effects (Ruhrchemie AG/Safepharm, 1985).

This study was judged to be reliable with restrictions (RL2), due to missing information on substance composition or purity.

The proportions of n- or iso-undecanal of the test material was not reported. Read Across is therefore considered. Refer to the discussion field of the endpoint summary for detailed justification of read across.