Dierbium trioxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5 November 1990 - 8 November 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study performed in accordance with generally accepted scientific principles, possibly with incomplete reporting or methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Reference 2

Reference Type:

publication

Title:

Acute Toxicological Evaluation of Erbium Oxide

Author:

Lambert, C.E., Barnum, E.C. and Shapiro, R.

Year:

1993

Bibliographic source:

Int. J. Toxicol., 12(6): 619

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: FHSA 16 CFR 1500.41

Deviations:

no

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Dierbium trioxide

EC Number:

235-045-7

EC Name:

Dierbium trioxide

Cas Number:

12061-16-4

Molecular formula:

Er2O3

IUPAC Name:

dierbium(3+) trioxidandiide

Constituent 2

Reference substance name:

Erbium Oxide

IUPAC Name:

Erbium Oxide

Test material form:

solid: particulate/powder

Details on test material:

Appearance: pink powdered solid

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Acclimation period: 12 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 23 °C

IN-LIFE DATES: From: 5 November 1990 To: 8 November 1990

Test system

Type of coverage:

occlusive

Preparation of test site:

other: abraded and shaved

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5 g of the test material was placed on each of the test sites (i.e. abraded and intact skin).

Duration of treatment / exposure:

24 hours

Observation period:

72 hours. Evaluation occurred 24 and 72 hours after exposure.

Number of animals:

6

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm² (two per rabbit, one intact and one abraded).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): the test sites were gently wiped clean of any residual test material.
- Time after start of exposure: after 24 hours of exposure.

SCORING SYSTEM:

Erythema and eschar formation:
0: No erythema:
1: Very slight erythema (barely perceptible)
2: Well-defined erythema
3: Moderate to severe erythema
4: Severe erythema (beet redness) or eschar formation (injuries in depth) preventing erythema reading

Oedema formation:
0: No oedema
1: Very slight oedema (barely perceptible)
2: Slight oedema (edges of area well-defined by definite raising)
3: Moderate oedema (edges raised approximately 1 millimetre)
4: Severe oedema (raised more than 1 millimetre and extending beyond the area of exposure)

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Remarks:

of 6 animals

Time point:

other: mean at 24 and 72 hours

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

other: mean at 24 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Intact skin

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

other: mean at 24 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Abraded skin

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

other: mean at 24 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Intact skin

Results 5

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

other: mean of 24 and 72 hours

Score:

0

Max. score:

4

Reversibility:

other: not applicable

Remarks on result:

other: Abraded skin

Irritant / corrosive response data:

All sites were clear of irritation during the test period.

Other effects:

All animals appeared active and healthy.

Any other information on results incl. tables

Table 1 Primary Dermal Irritation (PDI) Scores - Individual Results

Rabbit	24 hours		72 hours
	Abraded	Intact	Abraded	Intact
7740 7741 7742 7743 7744 7745	0/0 0/0 0/0 0/0 0/0 0/0	0/0 0/0 0/0 0/0 0/0 0/0	0/0 0/0 0/0 0/0 0/0 0/0	0/0 0/0 0/0 0/0 0/0 0/0
Total	0/0	0/0	0/0	0/0
Mean	0/0	0/0	0/0	0/0

Key: erythema and eschar / oedema

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to EU criteria.

Conclusions:

Under the conditions of this study, the test material is not irritating to skin and requires no classification in accordance with the EU criteria.

Executive summary:

The primary skin irritation potential of the test material was investigated in a study which was broadly conducted in accordance with the FHSA guideline 16 CFR 1500.41.

During the study 0.5 g of the test material was applied to both an intact and abraded site on each of six New Zealand White rabbits. The sites were occluded for 24 hours. The patches were then removed and the test sites wiped to prevent further exposure. Evaluation occurred 24 and 72 hours after exposure.

All sites were clear of irritation during the test period and the Primary Dermal Irritation Index was 0.0.

Under the conditions of this study, the test material is not irritating to skin and requires no classification in accordance with the EU criteria.