Reaction mass of cerium dioxide and lanthanum oxide and lanthanum fluoride

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

November - December 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to OECD TG 402-compliant study, using a main constituent of the reaction mass for a read-across purpose

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Remarks:

/ Study performed before the application of the OECD test guideline 402 but consistent with technical standards (number of animals used, duration of observation period, observations and measurements...)

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Cerium dioxide

EC Number:

215-150-4

EC Name:

Cerium dioxide

Cas Number:

1306-38-3

Molecular formula:

CeO2

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Iffa Credo
- Age at study initiation: 6 to 7 weeks old
- Weight at study initiation: 180 - 190 g (males) / 150 - 160 g (females)
- Fasting period before study: no
- Housing: individually in 37.5 x 17 x 15 cm cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: no data


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 5
- Humidity (%): 55 +/- 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): not specified


IN-LIFE DATES: From: 25 November 1982 To: 2 December 1982

Administration / exposure

Type of coverage:

occlusive

Vehicle:

other: 10% aqueous gum arabic

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal skin
- % coverage: not specified
- Type of wrap if used: aluminium foil and tape


REMOVAL OF TEST SUBSTANCE
- Washing: no
- Time after start of exposure (removal of dressing): 24 hours


TEST MATERIAL
- Suspension in vehicle applied
- No other details provided

VEHICLE
No details provided

Duration of exposure:

24 hours of occlusive dressing

Doses:

- Preliminary assay: 1000 and 2000 mg/kg
- Main assay: 0 (vehicle) and 2000 mg/kg

No. of animals per sex per dose:

- Preliminary assay: 2/sex
- Main assay: 5/sex

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality, clinical signs and local tolerance: just after dosing, 1, 2, 6 hours after dosing and daily for 14 days
Body weight: days 0, 1, 2, 4, 7 and 14
- Necropsy of survivors performed: yes

Statistics:

Not included

Results and discussion

Preliminary study:

Two groups of 2 rats per sex, clipped on the back 24 hours before, were applied a single cutaneous dose of 1000 or 2000 mg/kg kept under an occlusive dressing (adhesive tape and aluminium foil) for 24 hours, and observed for 14 days. No mortality was observed at either dose level.

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD0

Effect level:

2 000 mg/kg bw

Based on:

act. ingr.

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

No mortality occurred during the observation period

Clinical signs:

other: Slightly reduced activity was observed on day 1 in rats exposed to the test substance. No signs of cutaneous irritation were seen.

Gross pathology:

No relevant findings were seen at necropsy on day 14

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: other: Annex VI Directive 67/548/EEC or UN/EU GHS

Conclusions:

Dermal LD50 higher than 2000 mg/kg for males and females

Executive summary:

In an acute dermal toxicity study (Institut Français de Toxicologie report No. 301229), groups of 6 to 7-week old Sprague-Dawley rats (5/sex) were applied a single dermal dose of Cerium Oxide, as a suspension in 10% gum arabic, at doses of 0 (vehicle only) or 2000 mg/kg bw (limit test) under an occlusive dressing applied for 24 hours, and observed for 14 days. Mortality, clinical signs and local tolerance were checked just after application, at 1, 2, 6 hours after dosing, and daily for 14 days. Body weight was recorded on days 0, 1, 2, 4, 7 and 14.

 

No mortality occurred during the observation period. Slightly reduced activity was observed on day1 in rats exposed to the test substance. No signs of cutaneous irritation were seen. No significant changes in body weight were seen when compared to controls. No relevant findings were seen at necropsy on day 14.

 

Therefore, the dermal LD50 was higher than 2000 mg/kg for males and females. No classification for acute dermal toxicity is warranted based on the absence of mortality up to a limit dose level, according to the criteria of Annex VI Directive 67/548/EEC or UN/EU GHS.

 

This study is classified as acceptable. Its design is compatible with the OECD 402 guideline requirements for acute dermal toxicity.