tetraammine palladium (II) hydrogen carbonate

Endpoint summary

Description of key information

In an in vivo guinea pig maximisation test (GPMT), conducted to GLP and according to OECD Test Guideline 406, tetraamminepalladium(II) hydrogen carbonate exhibited skin sensitising potential in all ten tested animals and was therefore classified as an extreme sensitiser (Allen, 1997b).

In an in vivo guinea pig maximisation test (GPMT), conducted to GLP and according to OECD Test Guideline 406, tetraamminepalladium dichloride exhibited moderate skin sensitising potential (Allen, 2000).

 

No respiratory tract sensitisation data are available.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study performed between 21 February and 27 March 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

OECD guidleine study, to GLP, conducted prior to the LLNA. No reporting of test purity and stability.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

not specified

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study conducted in 1997

Specific details on test material used for the study:

TEST MATERIAL
- Physical state: Pale yellow powder
- Source and lot/batch No.of test material: DD0274
- Expiration date of the lot/batch: no data
- Purity test date: no data

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: no data

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

not specified

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: David Hall Ltd, Staffordshire, UK
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 374-425 g
- Fasting period before study: no data
- Housing: singly or in pairs in solid-floor polypropylene cages furnished with woodflakes
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-22
- Humidity (%): 49-68
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: no data

Route:

intradermal and epicutaneous

Vehicle:

arachis oil

Concentration / amount:

0.01% intradermal induction (with and without Freund's Complete Adjuvant (FCA)), 5% topical induction, and 1 and 2% topical challenge

Route:

other: epicutaneous, but no further details in study report on whether occlusive or semi-occlusive

Vehicle:

arachis oil

Concentration / amount:

1 and 2% topical challenge

No. of animals per dose:

Ten test animals in total (and 5 controls)

Details on study design:

RANGE FINDING TESTS: A sighting test was carried out with six guinea pigs involving intradermal injections (induction phase) of the test material at varying concentrations between 0.01 and 5% in distilled water, a 48-hr topical (induction) application of the test material at concentrations between 0.05 and 75% (in arachis oil) in four guinea pigs, and a 24-hr topical (challenge) application at 0.5-5% (in arachis oil) in two guinea pigs. The highest concentration producing only mild to moderate dermal irritaiton was selected for the topical induction stage of the main study and the highest non-irritant concentration and one lower were selected for the challange stage.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: intradermal injection (no details in study report on numbers) and single patch test
- Exposure period: 48-hr occlusive patch test
- Test groups: ten animals in total
- Control group: five animals
- Site: shoulder region, clippped
- Frequency of applications: a row of 3 injections (0.1 ml each) were made on each side of the mid-line. One week later, on the same clipped shoulder region, the occlusive patch-test was applied and held in place for 48 hr.
- Concentrations: 0.01% intradermal induction and 5% topical induction

B. CHALLENGE EXPOSURE
- No. of exposures: Single patch tests
- Exposure period: 24-hr occlusive patch test
- Test groups: ten animals in total
- Control group: five animals
- Site: clipped flanks
- Concentrations: 1 and 2% topical challenge
- Evaluation (hr after challenge): 24 and 48-hrs after patch removal

OTHER: Bodyweights were measured on day 0 and day 24.

Challenge controls:

Topical challenge with the test material at a concentration of 1 and 2% in arachis oil

Positive control substance(s):

yes

Remarks:

hexylcinnameldehyde 85%, 2-mercaptobenzothiazole, ethyl 4-aminobenzoate 98%, 2,4-dinitrochlorobenzene

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

1 and 2%

No. with + reactions:

10

Total no. in group:

10

Clinical observations:

Erythema seen in all animals at challenge with 1 and 2%. Oedema seen in seven animals at 1% and all ten animals at 2% challenge.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 1 and 2%. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: Erythema seen in all animals at challenge with 1 and 2%. Oedema seen in seven animals at 1% and all ten animals at 2% challenge.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No erythema or oedema seen in any of the controls

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: No erythema or oedema seen in any of the controls.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1 and 2%

No. with + reactions:

10

Total no. in group:

10

Clinical observations:

Erythema recorded in all ten animals at both concentrations. Oedema was recorded in two animals at 1% and in four animals at 2%. Desquamation was also seen in two guinea pigs.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1 and 2%. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: Erythema recorded in all ten animals at both concentrations. Oedema was recorded in two animals at 1% and in four animals at 2%. Desquamation was also seen in two guinea pigs..

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

No erythema or oedema seen in any of the controls

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: No erythema or oedema seen in any of the controls.

Group:

positive control

Remarks on result:

other: provided overview summary results of several positive control tests using known sensitizers demonstrate suitability of test system.

Remarks:

positive control materials: hexylcinnameldehyde 85%, 2-mercaptobenzothiazole, ethyl 4-aminobenzoate 98%, 2,4-dinitrochlorobenzene

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

In an in vivo guinea pig maximisation test (GPMT), conducted to GLP and according to OECD Test Guideline 406, tetraamminepalladium(II) hydrogen carbonate exhibited skin sensitising potential in all ten tested animals and was therefore classified as an extreme skin sensitiser.

Executive summary:

Tetraamminepalladium hydrogen carbonate was assessed for its contact sensitising potential in a guinea pig maximisation test maximum test (GPMT) conducted according to OECD Test Guideline 406, and to GLP.

 

A group of ten animals were induced by intradermal injection (with and without Freunds Complete Adjuvant; FCA) at a concentration of 0.01% of the test material (in arachis oil) to the clipped shoulder region. One week later, at the same site, they recieved a occlusive 48 -hr patch-test at a concentration of 5% (again in arachis oil). Challenge doses of 1 and 2% (in arachis oil) were applied (occulsive patch test) 2 weeks later to the clipped flanks of treated animals and the areas examined 24 and 48 hr after patch removal for erythema, oedema and other skin reactions. A further group of five animals were used as controls, receiving the same induction procedure (involving vehicle and FCA) but without the test substance, and challenged similarly to the treatment group.

 

Erythema was seen in all treated animals 24- and 48-hr after challenge with 1 and 2% of the test material. Oedema was seen in seven of the treated animals at 1% and in all ten treated animals at 2%, 24-hrs after removal of the challenge patch tests. The number of animals with oedema was reduced to two and four, 48-hrs after removal of the 1 and 2% challenge patch tests, respectively. Desquamation was also seen in two guinea pigs. All animals gained weight over the study period, and body weight gains from day 0 to day 24 appeared comparable between the treated and control groups.

 

In summary, a maximisation test involving a topical challenge application of tetraamminepalladium(II) hydrogen carbonate at a concentration of 1 and 2% to the skin of guinea pigs produced sensitisation reactions in all ten animals; a 100% (10/10) sensitisation rate. No skin reactions were recorded oin the five controls. The test material exhibited extreme skin sensitising potential in this study.

 

According to EU CLP criteria (EC 1272/2008), tetraamminepalladium(II) hydrogen carbonate should be classified as a skin sensitiser (category 1A).

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-16 June 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline study, to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study conducted in 2000

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: David Hall Limited
Burton-on-Trent
Staffordshire
UK
- Age at study initiation:
- Weight at study initiation: 347-421 g
- Housing: solid-floor polypropylene cages; bedding - woodchips
- Diet (e.g. ad libitum): conventional; ad libitum
- Water (e.g. ad libitum): tap water; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

0.01% in distilled water - injection
10% in distilled water - topical induction
1% and 2% in distilled water - topical challenge

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.01% in distilled water - injection
10% in distilled water - topical induction
1% and 2% in distilled water - topical challenge

No. of animals per dose:

10 (5 animals in control group)

Details on study design:

RANGE FINDING TESTS:
Intradermal induction: one animal each treated with 0.01, 0.05, 0.1, 0.5, 1.0 or 5% and examined for erythema at 24, 48 and 72 hr and at 7 days

Topical induction: Two guinea pigs (injected with Freund’s complete adjuvant 14 days earlier) each received applications of 5, 10, 25 and 50% of the test material under an occlusive dressing. Examined for erythema and odema at 1, 24 and 48 hr.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: One injection, followed 7 days later by topical application
- Exposure period: topical – 48 hr

- Test groups: Injection – three injections in shoulder region on each side of the mid-line as follows:
a) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
b) 0.01% w/w formulation of the test material in distilled water
c) 0.01% w/w formulation of the test material in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water.

- Control group: as above, but without the test material
- Site: shoulder region, on each side of the mid-line
- Frequency of applications: once
- Duration: topical – 48 hr
- Concentrations: 10%

B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: 14 days after the topical induction
- Exposure period: 24 hr
- Test groups:
- Control group: treated with test substance as test group
- Site: flank
- Concentrations: 1% to left flank, 2% to right flank
- Evaluation (hr after challenge): 24 and 48 hr

Challenge controls:

Treated as for test group

Positive control substance(s):

no

Positive control results:

No positive controls included in this study. A table giving historical positive control data for 2-mercaptobenzothiazole is included in the study report, showing between a 70-100% incidence of sensitisation in groups of ten female guinea pigs.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

No evidence of adverse effects

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: No evidence of adverse effects.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1%

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

No evidence of adverse effects

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1%. No with. + reactions: 5.0. Total no. in groups: 10.0. Clinical observations: No evidence of adverse effects.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident..

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident..

Group:

positive control

Remarks on result:

other: provided overview summary results of several positive control tests using known sensitizers demonstrate suitability of test system.

Remarks:

positive test material: 2-mercaptobenzothiazole

In test group with 2% challenge dose, at 48 hr 6 animals showed erythema (grades 1 and 2) and one animal had odema (at 24 hr the totals were 9 and 4, respectively for erythema and odema. Reactions that had disappeared by 48 hr were not attributed to sensitisation).

In test group with 1% challenge dose, at 48 hr 5 animals showed erythema (grade 1) and one animal had odema (at 24 hr the totals were 9 and 1, respectively for erythema and odema. Reactions that had disappeared by 48 hr were not attributed to sensitisation).

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

In an in vivo guinea pig maximisation test (GPMT), conducted to GLP and according to OECD Test Guideline 406, tetraamminepalladium dichloride exhibited moderate skin sensitising potential

Executive summary:

Tetraammine palladium chloride was assessed for its contact sensitising potential in a guinea pig maximisation test (GPMT) conducted according to OECD Test Guideline 406, and to GLP.

A group of ten male animals were induced by intradermal injection of 0.1% of the test material (in distilled water), with and without Freund's Complete Adjuvant, followed 7 days later by topical exposure to 10% (in distilled water) under an occluded patch. Challenge doses of 1 and 2% (in distilled water) were applied to different sites 14 days later and the areas examined at 24 and 48 hr for erythema and oedema. A further group of five males were used as controls, receiving the same induction procedure but without the test substance, and challenged similarly to the treatment group.

Six of the ten treated animals showed evidence of sensitisation at 48 hr (erythema, grade 1 or 2); three further animals exhibited erythema at 24 hr but not at 48 hr and these reactions were therefore considered not to be due to sensitisation. Tetraamminepalladium chloride exhibited moderate skin sensitising potential in this study.

According to EU CLP criteria (EC 1272/2008), tetraamminepalladium chloride should be classifed as a skin sensitiser (category 1A).

Reference 3

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

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

Adequacy of study:

key study

Study period:

15-16 June 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline study, to GLP

Justification for type of information:

Within the category of tetraamminepalladium(II) compounds, data on three tetraamminepalladium(II) salts, the acetate, chloride, and hydrogen carbonate salts will be used to fill data gaps. Tetraamminepalladium(II) diacetate, dinitrate, dihydroxide, dichloride and di(hydrogencarbonate) are the target substances within the group. In all substances covered, the palladium is in the 2+ oxidation state, co-ordinated to four neutral ammonia molecules (giving an overall 2+ charge on the complex). Thus, the difference in anion (acetate, nitrate, hydroxide, chloride or hydrogen carbonate) represents the only structural difference between the compounds in this group. As detailed in the read-across justification report (cfr IUCLID section 13), all the human health toxicity data included in the category member dossiers should be considered equally applicable to each of the category member substances.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study conducted in 2000

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: David Hall Limited
Burton-on-Trent
Staffordshire
UK
- Age at study initiation:
- Weight at study initiation: 347-421 g
- Housing: solid-floor polypropylene cages; bedding - woodchips
- Diet (e.g. ad libitum): conventional; ad libitum
- Water (e.g. ad libitum): tap water; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-23
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

0.01% in distilled water - injection
10% in distilled water - topical induction
1% and 2% in distilled water - topical challenge

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

0.01% in distilled water - injection
10% in distilled water - topical induction
1% and 2% in distilled water - topical challenge

No. of animals per dose:

10 (5 animals in control group)

Details on study design:

RANGE FINDING TESTS:
Intradermal induction: one animal each treated with 0.01, 0.05, 0.1, 0.5, 1.0 or 5% and examined for erythema at 24, 48 and 72 hr and at 7 days

Topical induction: Two guinea pigs (injected with Freund’s complete adjuvant 14 days earlier) each received applications of 5, 10, 25 and 50% of the test material under an occlusive dressing. Examined for erythema and odema at 1, 24 and 48 hr.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: One injection, followed 7 days later by topical application
- Exposure period: topical – 48 hr

- Test groups: Injection – three injections in shoulder region on each side of the mid-line as follows:
a) Freund's Complete Adjuvant plus distilled water in the ratio 1:1
b) 0.01% w/w formulation of the test material in distilled water
c) 0.01% w/w formulation of the test material in a 1:1 preparation of Freund's Complete Adjuvant plus distilled water.

- Control group: as above, but without the test material
- Site: shoulder region, on each side of the mid-line
- Frequency of applications: once
- Duration: topical – 48 hr
- Concentrations: 10%

B. CHALLENGE EXPOSURE
- No. of exposures: one
- Day(s) of challenge: 14 days after the topical induction
- Exposure period: 24 hr
- Test groups:
- Control group: treated with test substance as test group
- Site: flank
- Concentrations: 1% to left flank, 2% to right flank
- Evaluation (hr after challenge): 24 and 48 hr

Challenge controls:

Treated as for test group

Positive control substance(s):

no

Positive control results:

No positive controls included in this study. A table giving historical positive control data for 2-mercaptobenzothiazole is included in the study report, showing between a 70-100% incidence of sensitisation in groups of ten female guinea pigs.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

2%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

No evidence of adverse effects

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 2%. No with. + reactions: 6.0. Total no. in groups: 10.0. Clinical observations: No evidence of adverse effects.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

1%

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

No evidence of adverse effects

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 1%. No with. + reactions: 5.0. Total no. in groups: 10.0. Clinical observations: No evidence of adverse effects.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident..

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

1 and 2%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 1 and 2%. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: One animal was found dead on day 14 from causes not related to the test material. No other clinical signs were evident..

Group:

positive control

Remarks on result:

other: provided overview summary results of several positive control tests using known sensitizers demonstrate suitability of test system.

Remarks:

positive test material: 2-mercaptobenzothiazole

In test group with 2% challenge dose, at 48 hr 6 animals showed erythema (grades 1 and 2) and one animal had odema (at 24 hr the totals were 9 and 4, respectively for erythema and odema. Reactions that had disappeared by 48 hr were not attributed to sensitisation).

In test group with 1% challenge dose, at 48 hr 5 animals showed erythema (grade 1) and one animal had odema (at 24 hr the totals were 9 and 1, respectively for erythema and odema. Reactions that had disappeared by 48 hr were not attributed to sensitisation).

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

In an in vivo guinea pig maximisation test (GPMT), conducted to GLP and according to OECD Test Guideline 406, tetraamminepalladium dichloride exhibited moderate skin sensitising potential

Executive summary:

Tetraammine palladium chloride was assessed for its contact sensitising potential in a guinea pig maximisation test (GPMT) conducted according to OECD Test Guideline 406, and to GLP.

A group of ten male animals were induced by intradermal injection of 0.1% of the test material (in distilled water), with and without Freund's Complete Adjuvant, followed 7 days later by topical exposure to 10% (in distilled water) under an occluded patch. Challenge doses of 1 and 2% (in distilled water) were applied to different sites 14 days later and the areas examined at 24 and 48 hr for erythema and oedema. A further group of five males were used as controls, receiving the same induction procedure but without the test substance, and challenged similarly to the treatment group.

Six of the ten treated animals showed evidence of sensitisation at 48 hr (erythema, grade 1 or 2); three further animals exhibited erythema at 24 hr but not at 48 hr and these reactions were therefore considered not to be due to sensitisation. Tetraamminepalladium chloride exhibited moderate skin sensitising potential in this study.

According to EU CLP criteria (EC 1272/2008), tetraamminepalladium chloride should be classifed as a skin sensitiser (category 1A).

Reference 4

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

No relevant human skin sensitisation data were identified. No in vitro skin sensitisation studies were identified, or are required, as reliable in vivo studies are already available.

 

Tetraamminepalladium(II) hydrogen carbonate was assessed for its contact sensitising potential in a GPMT conducted according to OECD Test Guideline 406, and to GLP. A group of ten guinea pigs were induced by intradermal injection (with and without Freund’s Complete Adjuvant; FCA) at a concentration of 0.01% of the test material (in arachis oil) to the clipped shoulder region. One week later, at the same site, they received a occlusive 48 -hr patch-test at a concentration of 5% (again in arachis oil). Challenge doses of 1 and 2% (in arachis oil) were applied (occlusive patch test) 2 weeks later to the clipped flanks of treated animals and the areas examined 24 and 48 hr after patch removal for erythema, oedema and other skin reactions. A further group of five animals were used as controls, receiving the same induction procedure (involving vehicle and FCA) but without the test substance, and challenged similarly to the treatment group. Erythema was seen in all treated animals 24- and 48-hr after challenge with 1 and 2% of the test material. Oedema was seen in seven of the treated animals at 1% and in all ten treated animals at 2%, 24-hrs after removal of the challenge patch tests. The number of animals with oedema was reduced to two and four, 48-hrs after removal of the 1 and 2% challenge patch tests, respectively. Desquamation was also seen in two guinea pigs. All animals gained weight over the study period, and body weight gains from day 0 to day 24 appeared comparable between the treated and control groups. In summary, a maximisation test involving a topical challenge application of tetraamminepalladium(II) hydrogen carbonate at a concentration of 1 and 2% to the skin of guinea pigs produced sensitisation reactions in all ten animals; a 100% (10/10) sensitisation rate. No skin reactions were recorded in the five controls. The test material exhibited extreme skin sensitising potential in this study (Allen, 1997b).

Tetraamminepalladium dichloride was assessed for its contact sensitising potential in a guinea pig maximisation test (GPMT) conducted according to OECD Test Guideline 406, and to GLP. A group of ten male animals were induced by intradermal injection of 0.1% of the test material (in distilled water), with and without Freund's Complete Adjuvant, followed 7 days later by topical exposure to 10% (in distilled water) under an occluded patch. Challenge doses of 1 and 2% (in distilled water) were applied to different sites 14 days later and the areas examined at 24 and 48 hr for erythema and oedema. A further group of five males were used as controls, receiving the same induction procedure but without the test substance, and challenged similarly to the treatment group. Six of the ten treated animals showed evidence of sensitisation at 48 hr (erythema, grade 1 or 2); three further animals exhibited erythema at 24 hr but not at 48 hr and these reactions were therefore considered not to be due to sensitisation. Tetraamminepalladium dichloride exhibited moderate skin sensitising potential in this study (Allen, 2000).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

No respiratory tract sensitisation data are available. A new study was not conducted as no standard and validated test method is available and it is not a REACH Standard Information Requirement.

Justification for classification or non-classification

Based on the results of the available and reliable GPMT, tetraamminepalladium(II) hydrogen carbonate should be classified as a (strong) skin sensitiser (category 1A) according to EU CLP criteria (EC 1272/2008).