Dodecanal

Endpoint summary

Description of key information

In the absence of data on the target substance, data was presented on two analogue substances, 2-methylundecanal and Undec-10-enal.  The analogue substance 2-methylundecanal was assessed for skin irritation with rabbits dermally exposed to the test material for 24 hr.  The results of the study showed that the test material should be classified as a Category 2 skin irritant. This was supported by data from an assessment using Unde-10-enal.
In the absence of data on the target substance, data was presented on the analogue substance, Undec-10-enal, which was assessed for eye irritation in rabbits. The test substance was used to assess eye irritation using albino rabbits. Under the conditions of the test the test substance was found to be irritating to eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

A valid study is available for the analogue substance, 2-methylundecanal. The study meets generally accepted scientific standards with acceptable restrictions for the standard test. The read-across is considered to be suitable based on the structural and “mechanistic action” similarities between the target substance (Dodecanal) and source substance (2-methylundecanal) and their similar physico-chemical properties.

Qualifier:

no guideline followed

Principles of method if other than guideline:

4 rabbits were dermally exposed to the test material for 24 hr and then observed for 10 days. The study was repeated with 3 new rabbits with an observation period of 14 days.

GLP compliance:

no

Remarks:

Study predates GLP

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: No data
- Weight at study initiation: 2.8 to 3.0 kg
- Fasting period before study: No data
- Housing: No data
- Diet: No data
- Water: No data
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data
- Humidity (%): No data
- Air changes (per hr): No data
- Photoperiod: No data

Type of coverage:

not specified

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount applied: 10 mL/kg

Duration of treatment / exposure:

24 hr

Observation period:

10 days (test group 1)
14 days (test group 2)

Number of animals:

2 male, 2 female (test group 1)
2 male, 1 female (test group 2)

Details on study design:

TEST SITE
- Area of exposure: No data
- % coverage: No data
- Type of wrap if used: damming

REMOVAL OF TEST SUBSTANCE
- Washing: With water
- Time after start of exposure: 24 hr

SCORING SYSTEM:
- Not explicitly stated, although scoring can be presumed to be the standard scoring system of Draize (1959), and this matches details given in the text.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

4

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

4

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

2

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period

Irritation parameter:

erythema score

Basis:

animal #4

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

3

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

4

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period. Oedema was replaced by a shell of hard peeling skin by day 7.

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

4

Reversibility:

not fully reversible within: 10 d

Remarks on result:

other: 10 day observation period. Oedema was replaced by a shell of hard peeling skin by day 7

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

0

Remarks on result:

other: 10 day observation period

Irritation parameter:

edema score

Basis:

animal #4

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

1

Reversibility:

fully reversible within: 7 d

Remarks on result:

other: 10 day observation period

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

2

Reversibility:

not fully reversible within: 14 d

Remarks on result:

other: 14 day observation period

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

4

Reversibility:

not fully reversible within: 14 d

Remarks on result:

other: 14 day observation period

Irritation parameter:

erythema score

Basis:

animal #3

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

2

Reversibility:

not fully reversible within: 14 d

Remarks on result:

other: 14 day observation period

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

0

Remarks on result:

other: 14 day observation period

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

3

Reversibility:

fully reversible within: 6 d

Remarks on result:

other: 14 day observation period. Oedema was replaced by a shell of hard peeling skin by day 6.

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

0

Remarks on result:

other: 14 day observation period

Irritation parameter:

erythema score

Basis:

mean

Remarks:

All animals

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

3.25

Remarks on result:

other: 10 day observation period

Irritation parameter:

edema score

Basis:

mean

Remarks:

All animals

Time point:

other: Mean of scores at 24, 48 and 72 h

Score:

2.25

Remarks on result:

other: Observation period 10 days

For full details on results, see the attached supporting material.

Interpretation of results:

Category 2 (irritant)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test substance was assessed for skin irritation using rabbits. In accordance with the classification criteria set out in CLP Regulation (EC) no. 1272/2008 the results obtained determine that the test material 2-methylundecanal should be classified as a Category 2 skin irritant.
A valid study is available for the analogue substance, 2-methylundecanal. The study meets generally accepted scientific standards with acceptable restrictions for the standard test. The read-across is considered to be suitable based on the structural and “mechanistic action” similarities between the target substance (Dodecanal) and source substance (2-methylundecanal) and their similar physico-chemical properties.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

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

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

A valid study is available for the analogue substance, Undec-10-enal. The study meets generally accepted scientific standards with acceptable restrictions for the standard test. The read-across is considered to be suitable based on the structural and “mechanistic action” similarities between the target substance (Dodecanal) and source substance (Undec-10-enal) and their similar physico-chemical properties.

Qualifier:

according to guideline

Guideline:

other: Draize test as described in "Appraisal of the Safety of Chemicals in Food, Drugs and Cosmetics", Association of Food and Drug Officials of the United States

Deviations:

not specified

Principles of method if other than guideline:

Ocular Draize test.

GLP compliance:

no

Species:

rabbit

Strain:

other: Albino, not specified

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: No data
- Weight at study initiation: No data
- Housing: No data
- Diet (e.g. ad libitum): No data
- Water (e.g. ad libitum): No data
- Acclimation period: No data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data
- Humidity (%): No data
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): No data

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Volume applied: 0.1 mL

Duration of treatment / exposure:

Single exposure

Observation period (in vivo):

7 d (observations at 1 d, 2d, 3 d, 4 d, 7 d)

Number of animals or in vitro replicates:

3

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Not performed

SCORING SYSTEM:
- Draize scale.
- The scoring system is explained fully in the attached supporting information for the results section.

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

4

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

4

Irritation parameter:

iris score

Basis:

animal #1

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

animal #2

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

2

Irritation parameter:

iris score

Basis:

animal #3

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

0

Max. score:

2

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #1

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

2.667

Max. score:

3

Reversibility:

fully reversible within: 7 d

Remarks on result:

other: Contributing to positive classification as category 2 eye irritant.

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #2

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 7 d

Remarks on result:

other: Contributing to positive classification as category 2 eye irritant.

Irritation parameter:

conjunctivae score

Remarks:

redness

Basis:

animal #3

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

1.667

Max. score:

3

Reversibility:

fully reversible within: 4 d

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

2.333

Max. score:

4

Reversibility:

fully reversible within: 7 d

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

1.667

Max. score:

4

Reversibility:

fully reversible within: 7 d

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

other: Mean of scores at 24 hrs, 48 hrs, 72 hrs

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 4 d

Irritant / corrosive response data:

For full results please refer to the attached supporting information.

Interpretation of results:

Category 2A (irritating to eyes)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test substance was used to assess eye irritation using albino rabbits. Under the conditions of the test the test substance was found to be irritating to eyes.

A valid study is available for the analogue substance, Undec-10-enal. The study meets generally accepted scientific standards with acceptable restrictions for the standard test. The read-across is considered to be suitable based on the structural and “mechanistic action” similarities between the target substance (Dodecanal) and source substance (Undec-10-enal) and their similar physico-chemical properties.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In the absence of data on the target substance, data was presented on two analogue substances, 2-methylundecanal and Undec-10-enal.

2-methylundecanal was assessed for skin irritation with rabbits dermally exposed to the test material for 24 hr. The study was performed in two parts. Initially 4 rabbits were exposed to the unchanged test substance and observed over a 10-day period; in the second part, 3 rabbits were exposed to the unchanged test substance and were observed for 14 days. Erythema and oedema were observed in most of the animals tested in both groups with a number showing reactions that were not reversible within the observation period. It was concluded that the test material should therefore be classified as a Category 2 skin irritant. A supporting study using guinea pigs was also performed and showed that under the conditions of the test, the test was found to be mildly irritating to guinea pigs at 5 % concentration. A further study on Undec-10-enal, which assessed skin irritation in rabbits showed the primary dermal irritation index was 1.2 at 24 and 72 hours. In this study, the test substance was considered mildly irritating, as there was some evidence of erythema, but no oedema.

The analogue substance Unde-10-enal was assessed for eye irritation in rabbits. Under the conditions of the test the test substance was found to be irritating to eyes.

Justification for selection of skin irritation / corrosion endpoint:
Most reliable available study.

Justification for selection of eye irritation endpoint:
Only available study.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: irritating

Justification for classification or non-classification

According to the results of the key study, performed on an analogue substance, the substance should be classified as a skin irritant category 2 in accordance with Regulation (EC) No. 1272/2008.

According to the results of the key study, performed on an analogue substance, the substance should be classified as an eye irritant in accordance with Regulation (EC) No. 1272/2008.