(2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tris(hexamethylene) isocyanate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Klimisch reliability of study is 1 (GLP guideline study); according to ECHA Practical Guide 6 rel. 2 is selected from the IUCLID pick-list as this should be the maximum score for read-across.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

(1992)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

HDI oligomers, isocyanurate

IUPAC Name:

HDI oligomers, isocyanurate

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Regal Group UK, Great Bookham, Surrey, UK.
- Age at study initiation: approx. 13 to 14 weeks
- Weight at study initiation: weight range of 3.0 - 3.4 kg
- Housing: individually in metal cages with perforated floors
- Diet and water: ad libitum
- Acclimation period: All rabbits were acclimatised to the experimental environment. No information concerning period of time.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): approx. 19
- Humidity (%): 30-70
- Air changes (per hr): approx. 19
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

unchanged (no vehicle)

Controls:

other: untreated skin areas of the test animal served as control

Amount / concentration applied:

0.5 mL

Duration of treatment / exposure:

4 hours

Observation period:

Examinations were terminated after 6 days, since all changes had completely subsided then.

Number of animals:

3 (two males, one female)

Details on study design:

TEST SITE: Approximately 24 hours prior to application of the test substance, hair was removed with electic clippers from the dorso-lumbar region of each rabbit exposing an area of skin approximately 100 mm x 100 mm. Approximately 0.5 mL of the test substance was applied under a 25 mm x 25 mm gauze pad to one intact site on each animal. Each treatment site was covered with "Elastoplast" elastic adhesive dressing for four hours.

REMOVAL OF TEST SUBSTANCE: At the end of the exposure period, the semi-occlusive dressing and gauze pad were removed and the treatment site was washed with warm water (30-40°C) to remove any residual test substance. The treated area was blotted dry with absorbent paper.

SCORING SYSTEM:
Erythema and eschar formation: No erythema 0; very slight erythema (barely perceptible) 1; well-defined erythema 2; moderate to severe erythema 3; severe erythema (beef redness) to slight eschar formation (injuries in depth) preventing erythema reading 4.
Oedema formation: 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 erythema (raised more than 1 millimetre and extending beyond the area of exposure) 4.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: #1, #3

Time point:

other: 24, 48, 72 hours

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 5 days

Results 2

Irritation parameter:

erythema score

Basis:

animal #2

Time point:

other: 24, 48, 72 hours

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 6 days

Results 3

Irritation parameter:

edema score

Basis:

animal #1

Time point:

other: 24, 48, 72 hours

Score:

>= 0 - <= 1

Max. score:

4

Reversibility:

fully reversible within: 4 days

Remarks on result:

other: mean score: 0.66

Results 4

Irritation parameter:

edema score

Basis:

animal #2

Time point:

other: 24, 48, 72 hours

Score:

>= 1 - <= 2

Max. score:

4

Reversibility:

fully reversible within: 5 days

Remarks on result:

other: mean score: 1.7

Results 5

Irritation parameter:

edema score

Basis:

animal #3

Time point:

other: 24, 48, 72 hours

Score:

0

Max. score:

4

Irritant / corrosive response data:

Very slight erythema with or without very slight to slight oedema was seen in all animals. These reactions gradually ameliorated and had resolved in all instances by Day 5 or Day 6.

Other effects:

There were no signs of toxicity or ill health in any rabbit during the observation period.

Any other information on results incl. tables

For (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)-triyl)tris(hexamethylene) isocyanate (EC 223-242-0, CAS 3779-63-3, mono constituent substance), in the following referred to as "HDI Trimer pure", a read across from the close structural analogue HDI oligomers, isocyanurate type (EC 931-274-8, CAS 28182-81-2, UVCB) is applied. A justification for the read-across with special focus on inhalation toxicity was elaborated and is attached to the chapter endpoint summary. Based on this justification all available toxicological data for HDI oligomers, isocyanurate type can be used for the toxicological evaluation of HDI Trimer pure. This approach is in accordance with Annex XI, section 1.5 of the REACH Regulation (EC) No 1907/2006.

Applicant's summary and conclusion

Executive summary:

An Acute Dermal Irritation/Corrosion test was conducted according to OECD TG 404. In this study very slight erythema with or without very slight to slight oedema was seen in all animals (Mean scores of time points 24, 48, and 72 h: 1 for erythema, 0.8 for oedema). These reactions gradually ameliorated and had resolved in all instances by Day 5 or Day 6. No signs of toxicity or ill health were observed.