Octa-1,7-diene

Endpoint summary

Description of key information

skin irritation / corrosion (similar to OECD 404): not classified
eye irritation (similar to OECD 405): not classified

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (24 h application duration, occlusive treatment, no 48 h reading performed, only 3-day observation period)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

(adopted in 2002)

Deviations:

yes

Remarks:

(6 animals, occlusive treatment, 24 h treatment, no 48 h reading time point, only 3-day observation period)

GLP compliance:

no

Remarks:

study performed prior to implementation of GLP

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: H. Fortkamp, Lengerich, Germany
- Age at study initiation: 11 - 17 weeks
- Weight at study initiation: 2.12 - 2.62 kg (mean weight: 2.36 kg)
- Housing: individually in steel grid floor cages
- Diet: Ssniff K Alleindiaet fuer Kaninchen (Ssniff Versuchstier GmbH, Soest, Germany); ad libitum
- Water: tap water; ad libitum
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23
- Humidity (%): 40 - 70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Preparation of test site:

other: shaved and abraded

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated skin of each animal served as control.

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

24 hours

Observation period:

3 days
Reading time points: 24 and 72 h

Number of animals:

6 females

Details on study design:

TEST SITE
- Area of exposure: 6.25 cm²
- Type of wrap if used: gauze, which was held in place by an adhesive and impervious bandage

REMOVAL OF TEST SUBSTANCE
- Washing: Residual test substance were wiped off with tissues.
- Time after start of exposure: 24 hours

SCORING SYSTEM: Evalutation was performed 25 - 26 h (defined as 24 h) and 72 h after start of application according to the Draize Scoring System.

Irritation parameter:

erythema score

Basis:

animal #1

Time point:

other: mean over 24 h and 72 h

Score:

1.5

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: no 48 h reading; 72 h observation period

Irritation parameter:

erythema score

Basis:

mean

Remarks:

out of 5 animals

Time point:

other: mean over 24 and 72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: no 48 h reading; 72 h observation period

Irritation parameter:

edema score

Basis:

mean

Remarks:

out of 6 animals

Time point:

other: mean over 24 and 72 h

Score:

1

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: no 48 h reading; 72 h observation period

Irritant / corrosive response data:

On the intact sites, all animals showed a grading score of 1 for erythema and edema at the 24 h and 72 reading time point except one animal with a grading score of 2 for erythema at the 72 h reading time point. On the abraded sites edema scores did not differ from the scores observed on the intact sites (constantly score 1). Erythema scores on the abraded sites were 1 at the 24 h reading time point in each rat and 1 or 2 in 3/6 animals each at the 72 h reading time point. Light brownish blotches were observed in 5/6 animals at the 72 h reading time point on the intact and abraded sites.

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

Slight skin irritating effects were seen in all animals but the mean values for erythema and edema on the basis of the 24 h and 72 h reading time points were below the classification criteria. The effects were not reversible, but as the observation period was only 3 days and the conditions (24 h treatment, occlusive conditions) were more rigorous than required by the current guideline, reversibility within an adequate observation period was assumed and classification for skin irriation is not warranted.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

adopted in 2012

Deviations:

yes

Remarks:

no pretreatment with topical anesthetics and systemic analgesics; 6 animals

GLP compliance:

no

Remarks:

study performed prior to implementation of GLP

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: H. Fortkamp, Lengerich, Germany
- Age at study initiation: 11 - 17 weeks
- Weight at study initiation: 2.45 - 2.94 kg
- Housing: individually in steel grid floor cages
- Diet: Ssniff K Alleindiaet fuer Kaninchen (Ssniff Versuchstier GmbH, Soest, Germany); ad libitum
- Water: mains water; ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 23
- Humidity (%): 40 - 70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Vehicle:

unchanged (no vehicle)

Controls:

other: The untreated right eye of each animal served as control.

Amount / concentration applied:

undiluted
Amount applied: 0.1 mL

Duration of treatment / exposure:

single application without washing

Observation period (in vivo):

7 days
Reading time points: 1 h and 1, 2, 3, 4 and 7 days after application

Number of animals or in vitro replicates:

6 males

Details on study design:

SCORING SYSTEM: Draize scoring system

TOOL USED TO ASSESS EYES: fluorescein (before treatment)

Irritation parameter:

cornea opacity score

Basis:

mean

Remarks:

out of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritation parameter:

iris score

Basis:

mean

Remarks:

out of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

2

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

3

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: 1-h reading: score = 1

Irritation parameter:

conjunctivae score

Basis:

mean

Remarks:

out of 4 animals (#2-#5)

Time point:

24/48/72 h

Score:

0.33

Max. score:

3

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: 1-h reading: score = 1 in 2/4 animals; score = 2 in 2/4 animals

Irritation parameter:

conjunctivae score

Basis:

animal #6

Time point:

24/48/72 h

Score:

0.67

Max. score:

3

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: 1-h reading: score = 1

Irritation parameter:

chemosis score

Basis:

mean

Remarks:

out of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: 1-h reading: score = 1 in 4/6 animals; score = 2 in 2/6 animals

Irritant / corrosive response data:

One hour after instillation of the test substance moderate chemosis (grade 2) associated with moderate reddening (grade 2) were observed in 2/6 animals. In the remaining 4 animals slight chemosis (grade 1) and slight reddening (grade 1) were noted. One day after treatment chemosis was no longer apparent in any animal and eye reaction was limited to slight reddening (grade 1) in the majority of animals. Two days after treatment only one animal showed slight reddening (grade 1) and 3 days after treatment no longer any effects were observed.

Other effects:

Initial pain reaction on instillation varied from practically no initial pain (a few blinks only; normal within one or two minutes) to slight initial pain (rabbit blinks and tries to open eye, but the reflexes close it).

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

Slight eye irritating effects (conjunctivae redness and swelling) were observed in all animals after instillation of the test substance. Almost all effects were reversible within 24 h and not later than 48 h. Thus, classification for eye irritation is not warranted.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin

The skin irritation potential of 1,7-octadiene has been investigated in two studies in rabbits.

A study investigating the skin irritation potential of 1,7-octadiene was performed in New Zealand White rabbits similar to OECD Guideline 404 (82-0224-DKT).

0.5 mL of the undiluted test substance was applied to the intact and abraded skin of 6 female rabbits under occlusive conditions for 24 h. The scoring of skin reactions (erythema and edema) was performed 24 and 72 h after patch removal. Slight erythema (mean scores over 24 h and 72 h: 1 in 5/6 animals and 1.5 in 1/6 animals) and slight edema (mean scores over 24 h and 72 h: 1 in all animals) were observed on the intact sites. The erythema scores for the abraded skin were higher in two animals at the 72 h reading time point (mean scores over 24 h and 72 h: 1 in 3/6 animals and 1.5 in 3/6 animals), whereas the grading for oedema was identical compared to the intact skin. However, abraded sites were not taken into account for assessment.

The effects were not reversible within the observation period of 3 days. Nevertheless, the test substance is not considered irritating because the observation period should have been extended to 14 days with occurring effects and, moreover, the conditions of the study (24 h instead of 4 h treatment duration, occlusive instead of semi-occlusive conditions) are more rigorous than required by the current guideline. Reversibility of the slight effects within an adequate observation period is assumed. Thus, 1,7-octadiene is not considered irritating to skin.

One further study investigating the skin irritation potential of 1,7-octadiene is available, in which primary skin irritation in rabbits is recorded in a 10-grade ordinal series (Smyth et al., 1962 and 1969). The evaluation of skin irritation was based on the severest reaction that developed on the clipped skin of each of 5 albino rabbits within 24 h after application of 0.01 mL of undiluted test sample or of solutions up to concentrations of 0.01% under open conditions. According to the scoring system, Grade 1 indicated no irritation and Grade 2 the least visible capillary injection from the undiluted chemical. Grade 6 indicated necrosis when undiluted and Grade 10 indicated necrosis from a 0.01% solution. In the study, a Grade 4 was determined after treatment with the undiluted test substance. However, these results were inconclusive for risk assessment, since no evaluation of skin irritation according to the Draize scoring system at 24, 48 and 72 h post-application was performed and no observation period was included to evaluate the reversibility of effects.

 

Eye

The eye irritation potential of 1,7-octadiene has been investigated in two in vivo studies.

In the first study, the eye irritation potential of 1,7-octadiene was determined in a study performed similar OECD Guideline 405 (82-0222-DKT). A single application of 0.1 mL of the undiluted test substance was applied in the conjunctival sac of one eye of 6 male New Zealand White rabbits. The other eye remained untreated and served as control. Examination and scoring of effects on the eyes were performed 1 h and 1, 2, 3, 4 and 7 days after test substance instillation. No effects on cornea and iris were seen. Moderate chemosis (grade 2) associated with moderate reddening (grade 2) were observed in 2/6 animals one hour after test substance application. In the remaining 4 animals slight chemosis (grade 1) and slight reddening (grade 1) were noted. One day after treatment chemosis was no longer apparent in any animal and eye reaction was limited to slight reddening (grade 1) in the majority of animals. Two days after treatment only one animal showed slight reddening (grade 1) and 3 days after treatment no longer any effects were observed. The mean cornea, iris and chemosis scores over 24, 48 and 72 h were 0 for all 6 animals, respectively. The mean conjunctivae scores were 0 and 0.33 for one animal each and 0.67 for 4 animals, respectively. Thus, based on the results of this study, 1,7-octadiene is not eye irritating.

One further study investigating the eye irritation potential of 1,7-octadiene is available, in which the eye injury in rabbits was recorded in a 10-grade ordinal series and evaluation of eye injury was based on the degree of corneal necrosis that resulted from instillation of various volumes and concentrations of the test substance (Smyth et al., 1962 and 1969). At most a very small area of necrosis was observed after installation of 0.5 mL of the undiluted test substance (Grade 1). However, these results were inconclusive for risk assessment, since no evaluation of eye irritation according to the Draize scoring system at 24, 48 and 72 h post-application was performed and no observation period was included to evaluate the reversibility of effects.

 

Justification for selection of skin irritation / corrosion endpoint:
The selected study is the most adequate and reliable study based on overall quality assessment.

Justification for selection of eye irritation endpoint:
The selected study is the most adequate and reliable study based on overall quality assessment.

Justification for classification or non-classification

Skin

The available data on skin irritation / corrosion of 1,7-octadiene do not meet the criteria for classification according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.

Eye

The available data on eye irritation of 1,7-octadiene do not meet the criteria for classification according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.