5-vinylnorborn-2-ene

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted to GLP with full study report available

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source:
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 15-23 g
- Housing: Individually housed in suspened polypropylene cages with stainless steel mesh lids on softwood flake bedding
- Diet: Certified rat and mouse diet from an accredited supplier, ad libitum
- Water : mains tap water ad libitum.
- Acclimation period: at least 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 Celsius (target)
- Humidity (%): 30 - 70 target
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light):

IN-LIFE DATES: From: To:

No. of animals per dose:

4

Details on study design:

RANGE FINDING TESTS:
- Number of animals: 1:
- Protocol: Daily application of 25ul to dorsal surface of each ear for 3 consecutive days.
- Irritation: none observed.

MAIN STUDY

- Criteria used to consider a positive response: 3 fold increase in dpm

TREATMENT PREPARATION AND ADMINISTRATION: Mice treated with undiluted test material or at concentrations of 25 and 50% in acetone/olive oil (4:1). Daily application of 25ul to the dorsal surface of each ear for 3 consecutive days. Five days following first topical application (Day 6) all mice injected via the tail vein with 250ul of phosphated buffer saline containing 3H-methyl thymidine giving a total dose of 20uCi to each mouse.

Parameter:

SI

Remarks on result:

other: Vehicle: na 25%v/v: 2.16 (Negative) 50%v/v: 3.42 (Positive) 100% v/v: 7.22 (Positive)

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Vehicle: 891.54/node 25% v/v: 1929.52/node 50% v/v: 3052.52/node 100% v/v: 6440.82/node

The concentration of the tested substance ENB expected to cause a 3-fold increase in 3HTdR incorporation was calculated to be 41.7% v/v in acetone/olive oil 4:1.

The results suggest that ENB is a weak sensitiser.

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

ENB is a sensitizer as at last one concentration resulted in a 3-fold or greater increase in tritiated TdR incorporation compared with controls

Executive summary:

In a guideline LLNA study conducted under GLP, 5-ethylidene-norborn-2-ene was shown to be a sensitizer at 50% v/v and neat. The result suggest that ENB is a weak sensitiser. This result can be considered representative of the likely sensitising potential of the close structural analogue vinyl norbornene.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In a guideline LLNA study conducted under GLP, 5-ethylidene-norborn-2-ene was shown to be a sensitizer at 50% v/v and neat. The result suggest that ENB is a weak sensitiser. This result can be considered representative of the likely sensitising potential of the close structural analogue vinyl norbornene.

Justification for selection of skin sensitisation endpoint:
Only study in dossier

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The results from a mouse LLNA study indicate that the close structural analogue ethylidene norbornene should be classified as a skin sensitiser. The quantitative data indicate that the response is weak and, according to the recommendations of ECETOC ("Contact Sensitisation: Classification according to potency", Technical Report 87, 2003) such a response would justify a classification limit for mixtures of 3% rather than the default of 1%. This result can be considered representative of the likely sensitisation potential of vinyl norbornene and therefore the conclusions regarding classification would also apply to the latter.

There is no data on respiratory sensitisation.