Palladium dichloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 February to 28 February 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD), to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

No untreated (control) areas; no evidence that systemic adverse effects were recorded.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

yes

Remarks:

No untreated (control) areas; no evidence that systemic adverse effects were recorded.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Palladium dichloride

EC Number:

231-596-2

EC Name:

Palladium dichloride

Cas Number:

7647-10-1

Molecular formula:

Cl2Pd

IUPAC Name:

palladium dichloride

Details on test material:

- Name of test material (as cited in study report): Palladium II chloride
- Substance type: brown powder
- Physical state: solid
- Analytical purity: no data
- Isomers composition: no data
- Lot/batch No.: MD0006
- Stability under test conditions: no data
- Storage condition of test material: room temperature in grey plastic tub

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: David Percival Ltd, Moston, Sandbach, Cheshire, UK
- Age at study initiation: 12-16 weeks
- Weight at study initiation: 2.3-2.5 kg
- Housing: Individually housed in suspended metal cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-21
- Humidity (%): 49-56
- Air changes (per hr): 15 changes
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To:

Test system

Type of coverage:

semiocclusive

Preparation of test site:

other: clipped

Vehicle:

water

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 ml

Duration of treatment / exposure:

Single 4 hour exposure

Observation period:

7 days

Number of animals:

3 (1 male and 2 females)

Details on study design:

TEST SITE
- Area of exposure: 2.5 cm x 2.5 cm
- % coverage:
- Type of wrap if used: The patch was secured with a strip of surgical adhesive tape (2.5 cm x 4 cm), and the trunk of each rabbit wrapped in an elasticated corset.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): any residual test material removed by gentle swabbing with cotton wool soaked in distilled water followed by diethyl ether
- Time after start of exposure: 4 hr

SCORING SYSTEM: The treated skin area was qualitatively and quantitatively scored using the Draize method at 1, 24, 48, and 72 hrs following removal of the patches (see OECD guidelines for grading of skin reactions). The primary irritation index is given by the sum of the values for erythema and oedema at the 24 and 72-hr readings and divided by 6.
Primary irritation index Classification
0 non-irritant
>0-2 mild irritant
>2-5 moderate irritant
>5-8 severe irritant
In addition, attention was paid to the occurrence of other skin reactions and irreversible alteration of the dermal tissue (which would lead to a classification of corrosive effects); systemic toxic effects were evidently not assessed.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

primary dermal irritation index (PDII)

Basis:

mean

Time point:

other: 24 and 72 hrs

Score:

ca. 3

Max. score:

8

Reversibility:

fully reversible within: 7 days (for erythema/ oedema), although crust formation and desquamation seen on day 7

Results 2

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24, 48 and 72 hr

Score:

3.2

Max. score:

8

Reversibility:

fully reversible within: 7 days (for erythema/ oedema), although crust formation and desquamation seen on day 7

Irritant / corrosive response data:

Very slight to well-defined erythema was noted in all three rabbits assessed at 1, 24, 48 and 72 hr after patch removal. Very slight (1 animal) to slight oedema (2 animals) was noted 1 hour after patch removal, with very slight to moderate oedema at the 24- and 48-hr observations. Very slight (1 animal), slight (1 animal), or no oedema (1 animal) was seen at the 72-hr observation.

Skin reactions noted in all three rabbits 7 days after treatment were crust formation and desquamation. No corrosive effects were noted.

Other effects:

No data

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In a guideline study, to GLP, palladium dichloride applied to the clipped skin of three rabbits (4-hr semi-occluded) produced a primary irritation index of 3 and was considered as a moderate irritant according to the Draize classification system. No corrosive effects were noted. However, as the test material produced “positive criteria” in only 1 of 3 rabbits according to the EU CLP criteria (i.e. a mean grade of >2.3 at the 24, 48 and 72 hr time for oedema in one animal only), classification as a skin irritant is not required.

Executive summary:

Palladium dichloride was investigated for irritant (and corrosive) effects following 4-hr (semi-occluded) application (0.5 g), moistened with 0.5 ml distilled water, to the clipped skin of three New Zealand white rabbits (one male and two females) in accordance with OECD Test Guideline 404 (with slight deviations), and to GLP. Following removal of the patch (and residual test material), the sites were observed for signs of erythema and oedema at 1, 24, 48 and 72 hrs using the Draize grading scores. The test site was again assessed at day 7; no untreated site (as recommended by the OECD) was apparently assessed.

Very slight to well-defined erythema and very slight to moderate oedema were seen. Crust formation or desquamation were observed on all three animals 7 days after treatment. The test material produced a primary irritation index of 3 (from the mean of the 24- and 72 -readings) and was considered as a moderate irritant according to the Draize classification system. No corrosive effects were noted.

However, as the test material produced “positive criteria” in only 1 of 3 rabbits according to the EU CLP criteria (i.e. a mean grade of >2.3 at the 24-, 48- and 72-hr time for oedema in one animal only), classification as a skin irritant is not required.