Praseodymium trichloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1963

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1963

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

not specified

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Species:

mouse

Strain:

CF-1

Sex:

male

Details on test animals or test system and environmental conditions:

No further data on test animals reported.

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

No further data on oral exposure reported.

Doses:

Not reported.

No. of animals per sex per dose:

40 male mice (total).

Control animals:

not specified

Details on study design:

No further data on oral exposure reported.

Statistics:

LD50 and standard errors calculated using the method of Litchfield and Wilcoxon (1949).

Preliminary study:

Not specified

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

4 500 mg/kg bw

Based on:

test mat.

95% CL:

> 4 054 - < 4 995

Mortality:

Some deaths occurred at 24 hours post-exposure. The peak of mortality was reported to occur at 48 h post-exposure. No further details reported.

Clinical signs:

Ataxia, writhing, laboured respiration, walking on toes with back arched, and sedation.

Body weight:

No data

Gross pathology:

No data

Other findings:

No data

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 of praseodymium trichloride to male mice was found to be 4500 mg/kg bw. The test substance is therefore considered not to be classified according to the CLP Regulation.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1963

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The method of Draize et al. (1944) was used to study ocular irritation in rabbits.

GLP compliance:

not specified

Species:

rabbit

Strain:

not specified

Details on test animals or tissues and environmental conditions:

No further data on test animals reported.

Vehicle:

water

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.1 mL into the conjunctival sac of one eye of each rabbit
- Concentration (if solution): 1:1 aqueous solution

Duration of treatment / exposure:

not reported

Observation period (in vivo):

4 weeks total, post-application

Number of animals or in vitro replicates:

3, sex not specified

Details on study design:

REMOVAL OF TEST SUBSTANCE: no data

SCORING SYSTEM: Draize scoring system

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

other: 1 hour

Score:

20

Max. score:

20

Reversibility:

fully reversible within: > 1 week

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

other: 1 hour

Score:

0

Max. score:

80

Remarks on result:

no indication of irritation

Irritation parameter:

iris score

Basis:

mean

Time point:

other: 1 hour

Score:

0

Max. score:

10

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

No effects were observed on cornea or iris, however, increased blinking rate and a maximum irritation index of 20 on the conjunctiva were observed within 1 hour after application. The test item produced conjunctival ulcers which persisted for 1 week, after which complete healing occurred. Observations over the next 3 weeks did not disclose any residual damage to the eye structures.

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

The test item was found to produce conjunctival ulcers in rabbits, which persisted for one week but after that healed completely. No effect was observed on cornea or iris. Based on the results of this study, the test item praseodymium trichloride would have to be classified as Eye irritant Cat. 2, according to the CLP Regulation.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1963

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Remarks:

Well performed study, however, the publication does not provide sufficient information to evaluate the results of the study taking into account current methodological requirements.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

not specified

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: CRW

Sex:

male/female

Details on test animals or test system and environmental conditions:

No further details on test animals reported.

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

CONCENTRATIONS IN DIET: 0.01%, 0.1% and 1% in diet (i.e. 0.1, 1 and 10 g/kg food, respectively)
No further details on exposure reported.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

No additional data.

Duration of treatment / exposure:

90 days

Frequency of treatment:

daily

Dose / conc.:

10 000 mg/kg diet

Dose / conc.:

1 000 mg/kg diet

Dose / conc.:

100 mg/kg diet

Dose / conc.:

0 mg/kg diet

No. of animals per sex per dose:

6 males and 6 females per dose

Control animals:

yes, plain diet

Details on study design:

No additional information.

Positive control:

Not specified.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Not specified

DETAILED CLINICAL OBSERVATIONS: Not specified

BODY WEIGHT: Yes
- Time schedule for examinations: Every 2 weeks

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Every 2 weeks
- Anaesthetic used for blood collection: Not specified
- Animals fasted: Not specified
- How many animals: Not specified
- Parameters examined: Total erythrocytes, total leucocytes, differential cell count, platelets, hemoglobin, hematocrit

CLINICAL CHEMISTRY: No

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

IMMUNOLOGY: No

Sacrifice and pathology:

GROSS PATHOLOGY: Not specified

HISTOPATHOLOGY: Yes, upon completion of the study
- Tissues examined: heart, lung, liver, kidney, spleen, pancreas, adrenal, and small intestine

Other examinations:

No data

Statistics:

Where appropriate, the results were analysed statistically by the method of Litchfield and Wilcoxon (1949).

Clinical signs:

not specified

Mortality:

not specified

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

The slight changes seen in the hemogram were probably related to the normal growth pattern of the animals and were within the range given by Gardner (1947). A normal pattern was also obtained with the differential cell counts.

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

At necropsy, all animals appeared normal.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Histopathologic examination of the tissues showed no differences between medicated and control groups.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Details on results:

No further details reported.

Dose descriptor:

NOAEL

Effect level:

>= 10 000 mg/kg diet

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

no

Conclusions:

The test item did not appear to have adverse effects on rats during and following 12 weeks of daily administration at dose levels of 0, 0.01%, 0.1% and 1% in diet, under the conditions of the test. No NOAEL could be determined due to absence of adverse effects. Therefore, an unbound NOAEL of >= 10000 mg/kg diet could be derived from the results of this study.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1964

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The method of Draize et al. (1944) was used to study skin irritation in rabbits.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Praseodymium trichloride

EC Number:

233-794-4

EC Name:

Praseodymium trichloride

Cas Number:

10361-79-2

Molecular formula:

PrCl3

IUPAC Name:

praseodymium trichloride

Test material form:

solid: particulate/powder

Details on test material:

No further details available

Test animals

Species:

rabbit

Strain:

not specified

Details on test animals or test system and environmental conditions:

No further data on test animals reported.

Test system

Type of coverage:

not specified

Preparation of test site:

other: intact and abraded skin

Vehicle:

unchanged (no vehicle)

Controls:

not specified

Amount / concentration applied:

0.5 g

Duration of treatment / exposure:

Not entirely clear.

Observation period:

7 days (up to 35 days for animals exposed to the test chemical on abraded skin)

Number of animals:

6, sex not specified

Details on study design:

TEST SITE: no data reported

REMOVAL OF TEST SUBSTANCE: no data reported

OBSERVATION TIME POINTS: not reported, but observations are reported after 24 h, 7 days, and 35 days (the latter only for abraded skin)

SCORING SYSTEM: Draize scoring system

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24 h

Score:

0

Max. score:

8

Remarks on result:

no indication of irritation

Remarks:

intact skin

Results 2

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

24 h

Score:

8

Max. score:

8

Reversibility:

fully reversible within: 35 days

Remarks on result:

probability of severe irritation

Remarks:

abraded skin

Irritant / corrosive response data:

- Direct application of the test item to intact rabbit skin produced no irritation within 24 hours, and no delayed reaction after 7 days.
- On abraded skin, there was a severe reaction after 24 hours with a maximum irritation index of 8. No change in irritation index was observed over the following 14 days, but complete healing with scars of 25-30 mm in diameter occurred at 35 days.
- It was mentioned that the liberation of nascent hydrochloric acid from the test item by tissue fluids may explain the difference in response between intact and abraded skin.

Other effects:

No additional information.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was found to be irritating to abraded skin, but non-irritating to intact skin. Therefore, and considering the requirements of current test guidelines, the test substance is considered to be not classified according to the CLP Regulation.