Palladium dichloride

Endpoint summary

Description of key information

Positive sensitisation responses to palladium dichloride have been observed following human patch testing (Cristaudo et al., 2005; Muris et al., 2014; Rebandel and Rudzki, 1990; Spiewak et al., 2014; Tillman et al., 2013; Yagami et al., 2014).

 

Palladium dichloride was described as a potent sensitiser in two GPMT investigations (Wahlberg and Boman, 1990, 1992). In a PLNA in mice, single subcutaneous injections of palladium dichloride induced a significant primary immune response (Schuppe et al., 1998).

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

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

Guinea-pig maximisation test.

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study completed in 1990.

Specific details on test material used for the study:

Not specified.

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

0.03 and 2.5%

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: Saline

Concentration / amount:

0.63 - 1.25%

Adequacy of challenge:

not specified

No. of animals per dose:

Not specified.

Details on study design:

GPMT
pretreatment: FCA
induction: intra- and epidermal (0.03 and 2.5% in water)
challenge: epidermal (0.63-1.25% in saline)

Challenge controls:

Not specified.

Positive control substance(s):

not specified

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Palladium dichloride was a potent skin sensitiser in a GPMT.

Executive summary:

The skin sensitising potential of palladium dichloride was investigated in a guinea pig maximisation test (GPMT). Animals were induced with test material (0.03 and 2.5 % in water) by the intradermal and epidermal routes, respectively, following pretreatment with Freund's complete adjuvant. Epidermal challenge (0.63 -1.25% in saline) indicated that palladium dichloride was a potent skin sensitiser in the GPMT.

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

Guinea-pig maximisation test.

GLP compliance:

not specified

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Study completed in 1992.

Specific details on test material used for the study:

Not specified.

Species:

guinea pig

Strain:

not specified

Sex:

not specified

Route:

intradermal and epicutaneous

Vehicle:

other: Saline

Concentration / amount:

0.03

Adequacy of induction:

not specified

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: Saline

Concentration / amount:

0.3 - 2.5%

Adequacy of challenge:

not specified

No. of animals per dose:

Not specified.

Details on study design:

H & S is a method developed by I.M. van Hoogstraten & R.J. Scheper and is similar to the GPMT (Note: The H & S-method was used because the GPMT fails to sensitize a sufficient number of animals with nickel sulfate [used as part of a test for cross reactivity]).
pretreatment: FCA
induction: intradermal (0.03% in saline),
challenge: epidermal (0.3-2.5% in saline)

Challenge controls:

Not specified.

Positive control substance(s):

not specified

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

Palladium dichloride was a potent skin sensitiser in a modified GPMT.

Executive summary:

The skin sensitising potential of palladium dichloride was investigated in a modified guinea pig maximisation test (GPMT; H &S method). Animals were induced with test material (0.03% in saline) by intradermal injection following pretreatment with Freund's complete adjuvant. Epidermal challenge (0.3 -2.5% in saline) indicated that palladium dichloride was a potent skin sensitiser in the GPMT.

Reference 3

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Principles of method if other than guideline:

Popliteal lymph node assay (PLNA)

GLP compliance:

not specified

Type of study:

other: popliteal lymph node assay (PLNA)

Justification for non-LLNA method:

Study conducted in 1998.

Species:

mouse

Strain:

Balb/c

Sex:

not specified

Route:

other: Subcutaneous

Vehicle:

not specified

Concentration / amount:

Not specified

Details on study design:

Not specified.

Challenge controls:

Not specified.

Positive control substance(s):

not specified

Remarks on result:

positive indication of skin sensitisation

Interpretation of results:

study cannot be used for classification

Remarks:

Indication of sensitisation

Conclusions:

In a PLNA in mice, single subcutaneous injections of PdCl2 induced a significant primary immune response.

Executive summary:

In a popliteal lymph node assay (PLNA) in mice, single subcutaneous injections of palladium(II) dichloride induced a dose-dependent reaction, with an increase in popliteal lymph node cellularity.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin patch tests produced a positive reaction to palladium dichloride in one worker out of 142 with prior exposure to platinum group elements (PGEs). No positive reactions were seen following skin prick tests with palladium dichloride in these 142 workers, and no positive skin reactions (following prick tests or patch tests) to palladium dichloride were seen in eleven office personnel with no prior exposure to PGEs (Cristaudo et al., 2005).

 

Skin patch tests with palladium dichloride (1 or 2% in petrolatum) produced a positive reaction in 154 of 1651 (9.3%) patients attending various European dermatology clinics (Muris et al., 2014).

 

Patch testing of 100 contact dermatitis patients with 1% aqueous palladium chloride revealed ten (all women) who were responsive to both nickel and the palladium compound (Rebandel and Rudzki, 1990).

 

A study abstract details patch testing with disodium tetrachloropalladate and palladium dichloride (3 and 2% in petrolatum, respectively) in 1026 patients (730 females and 296 males) with chronic/recurrent eczema aged 1-90 (median 40 years). Positive reactions with palladium dichloride were observed in 100 patients (9.7%) including 24 rated as clinically relevant and 30 as cross-reactions (Spiewak et al., 2014).

 

A group of 40 dermatitis patients patch tested on the upper back with palladium dichloride for 2 days at concentrations of 0.03, 0.096, 0.3, 0.96 and 3.0% (expressed as concentration of Pd2+) and observed on days 3 and 7 following exposure. Positive reactions were observed in all but 4 of the individuals (Tillman et al., 2013).

 

A total of 320 patients with suspected contact dermatitis were patch tested with palladium dichloride (1% in petrolatum) from three different sources. Positive rates were 5.0% [16/320], 4.7% [15/320] and 3.4% [11/320] (Yagami et al., 2014).

  

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

 

The skin sensitising potential of palladium dichloride was investigated in a guinea pig maximisation test (GPMT). Animals were induced with test material (0.03 and 2.5 % in water) by the intradermal and epidermal routes, respectively, following pretreatment with Freund's complete adjuvant (FCA). Epidermal challenge (0.63 -1.25% in saline) indicated that palladium dichloride was a potent skin sensitiser in the GPMT (Wahlberg and Boman, 1990).

 

In a modified GPMT (H &S method), animals were induced with test material (0.03% in saline) by intradermal injection following pretreatment with FCA. Epidermal challenge (0.3 -2.5% in saline) indicated that palladium dichloride was a potent skin sensitiser (Wahlberg and Boman, 1992).

 

In a popliteal lymph node assay (PLNA) in mice, single subcutaneous injections of palladium(II) dichloride induced a dose-dependent reaction, with an increase in popliteal lymph node cellularity (Schuppe et al., 1998).

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 (albeit limited) laboratory animal skin sensitisation studies on palladium dichloride , and positive skin sensitisation responses to palladium dichloride following human patch testing, it is appropriate to classify the substance as a skin sensitiser (category 1; no sub-classification is possible based on the current level of information) according to EU CLP criteria (EC 1272/2008).