Praseodymium(III,IV) oxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 December 1990 - 29 December 1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. No irritation scores recorded for the 48 hour time point.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according 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:

Praseodymium(III,IV) oxide

EC Number:

234-857-9

EC Name:

Praseodymium(III,IV) oxide

Cas Number:

12037-29-5

Molecular formula:

O11Pr6

IUPAC Name:

tetrakis(λ⁴-praseodymium(4+)) dipraseodymium(3+) undecaoxidandiide

Test material form:

solid: particulate/powder

Details on test material:

-Appearance: dark brown powder

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: Individually housed in suspended stainless steel caging with mesh floors
- Diet (e.g. ad libitum): ad libitum; pelleted Purina Rabbit Chow
- Water (e.g. ad libitum): Tap water supplied by automatic watering system supplied ad libitum
- Acclimation period: 20 days
- Source: Davidson’s Mill Farm, S. Brunswick, New Jersey

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 72 - 75 °F

IN-LIFE DATES: From: To: 26 December 1990 - 29 December 1990

Test system

Type of coverage:

occlusive

Preparation of test site:

other: shaved test sites with both intact and abraded skin

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

0.5g undiluted

Duration of treatment / exposure:

24 hours

Observation period:

72 hours

Number of animals:

3 males and 3 females

Details on study design:

-The rabbits were prepared by clipping the skin free of hair over approximately 10 % of the body surface (dorsal and ventral surfaces from scapular to pelvic area). Two test application sites, each approximately 2.5 cm² were delineated. One site was left intact while the other was abraded with a needle, taking special precaution not to penetrate the stratum corneum and not to cause bleeding.
-0.5 g test material was placed on each site and was immediately covered with a 2 x 2.25 inch adhesive-backed gauze patch. The patches and entire trunk of each rabbit were then wrapped with an elastic cloth to aid in maintaining test-patch position and to minimise evaporation.
-The patches were removed after 24 hours of exposure at which time the test sites were gently wiped clean of any residual test material.

Skin sites were evaluated at approximately 24 and 72 hours after initial exposure and scored as follows:

Erythema and eschar formation:

No erythema 0
Very slight erythema (barely perceptible) 1
Well-defined erythema 2
Moderate to severe erythema 3
Severe erythema (beet redness) or 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 (edges raised approximately 1 millimetre) 3
Severe oedema (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:

mean

Remarks:

of 6 animals

Time point:

24 h

Score:

0.17

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: Abraded sites

Results 2

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24 h

Score:

0.17

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Remarks on result:

other: Intact sites

Results 3

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Remarks on result:

not measured/tested

Results 4

Irritation parameter:

erythema score

Basis:

mean

Remarks:

of 6 animals

Time point:

72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Remarks:

Intact and Abraded sites

Results 5

Irritation parameter:

edema score

Basis:

mean

Remarks:

of 6 animals

Time point:

24/48/72 h

Score:

0

Max. score:

0

Remarks on result:

no indication of irritation

Remarks:

Intact and Abraded sites

Irritant / corrosive response data:

Very slight erythema without oedema was observed at both abraded and intact sites of one rabbit only at 24 hours post-dosing. By 72 hours, no irritation was observed.

Other effects:

All animals appeared active and healthy. There were no signs of gross toxicity, adverse pharmacologic effects or abnormal behaviour.

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
8058 8059 8060 8061 8062 8063	0/0 0/0 0/0 0/0 0/0 1/0	0/0 0/0 0/0 0/0 0/0 1/0	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	1/0	1/0	0/0	0/0
Mean	0.17/0	0.17/0	0/0	0/0

Key: erythema and eschar / oedema

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Criteria used for interpretation of results: EU

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 accordance with the FHSA guideline 16 CFR 1500.41.

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.

With the exception of one rabbit, which exhibited very slight erythema without oedema at both the intact and abraded site at 24 hours, all sites were clear of irritation during the test period (PDII = 0.09).

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