Palladium dichloride

Endpoint summary

Description of key information

In an early acute oral toxicity study, an LD50 value of approximately 576 mg/kg bw was reported in male rats gavaged with palladium dichloride dihydrate, and observed for up to 14 days. The analogous palladium dichloride LD50 is approximately 479 mg/kg bw (Holbrook et al., 1975).

No acute inhalation or dermal toxicity data were identified.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Conducted prior to standard OECD/EU test guidelines and GLP. While there is somewhat limited reporting of methods and results, the study appears scientifically acceptable.

Qualifier:

no guideline followed

Principles of method if other than guideline:

In the lethal dose experiments, male Sprague-Dawley rats received the tested palladium salt by gavage and were observed through a 14-day period. The LD50 values were calculated by the method of Litchfield and Wilcoxon. The exact dosing strategy is unclear and no details on pathological assessment are given.

GLP compliance:

no

Remarks:

(prior to GLP)

Test type:

other: No data

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: 4-5 weeks
- Weight at study initiation: 100-110 g
- Fasting period before study: No data
- Housing: No data
- Diet (e.g. ad libitum): Presumably ad libitum
- Water (e.g. ad libitum): Presumably ad libitum
- Acclimation period: 1-1.5 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data
- Humidity (%): No data
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): No data

IN-LIFE DATES: No data

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

No data

Doses:

No data

No. of animals per sex per dose:

No data

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: No data
- Necropsy of survivors performed: No data
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: No data

Statistics:

The LD50 values were calculated by the method of Litchfield and Wilcoxon.

Sex:

male

Dose descriptor:

LD50

Effect level:

576 mg/kg bw

Based on:

test mat.

95% CL:

>= 469 - <= 725

Remarks on result:

other: Evaluated by the method of Litchfield and Wilcoxon. The equivalent LD50 for palladium dichloride (anhydrous) is around 479 mg/kg bw (95% CL: 390 - 603 mg/kg bw).

Mortality:

Palladium salts often kill 4-10 days after administration. An LD50 of 2.7 mmol/kg bw (95% CL: 2.2-3.4 mmol/kg bw), using a molecular weight of approximately 213.34 g/mol, equates to 576.0 mg/kg bw (95% CL: 469.3-725.4 mg/kg bw). The equivalent LD50 for palladium dichloride (anhydrous) is 478.8 mg/kg bw (95% CL: 390.1 - 602.9 mg/kg bw), using amolecular weight of approximately 177.33 g/mol.

Clinical signs:

No data

Body weight:

No data

Gross pathology:

No data

Other findings:

No data

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In an early acute oral toxicity study, an LD50 value of approximately 576 mg/kg bw was reported in male rats gavaged with palladium dichloride dihydrate, and observed for up to 14 days. The analogous palladium dichloride LD50 is approximately 479 mg/kg bw.

Executive summary:

In an early acute oral toxicity study, groups of male Sprague-Dawley rats were administered palladium dichloride dihydrate by stomach tube and observed for 14 days. Using the prescribed statistical method, the acute oral median lethal dose (LD50) was found to be approximately 576 mg/kg bw (95% CL: 479 - 725 mg/kg bw). The analogous palladium dichloride LD50 is approximately 479 mg/kg bw (95% CL: 390 - 603 mg/kg bw).

Based on the results of this study, palladium dichloride should be classified for acute oral toxicity (category 4) according to EU CLP criteria (EC 1272/2008).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

479 mg/kg bw

Quality of whole database:

Overall, good-quality database which meets REACH Standard Information Requirements.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No relevant acute toxicity human data were identified.

In an early acute oral toxicity study, groups of male Sprague-Dawley rats were administered palladium dichloride dihydrate by stomach tube and observed for 14 days. Using the prescribed statistical method, the acute oral median lethal dose (LD50) was found to be approximately 576 mg/kg bw (95% CL: 479 - 725 mg/kg bw). The analogous palladium dichloride LD50 is approximately 479 mg/kg bw (95% CL: 390 - 603 mg/kg bw) (Holbrook et al., 1975). Based on the results of this study, palladium dichloride should be classified for acute oral toxicity (category 4) according to EU CLP criteria (EC 1272/2008). In a more recent acute oral toxicity study, conducted according to OECD Test Guideline 401 and to GLP, the acute oral LD50 of palladium dichloride was determined to be greater than 2 g/kg bw in the rat (Allen, 1994a). This suggests that the classification of palladium dichloride for acute oral toxicity, based on the early Holbrook et al., data, is a very health precautionary approach.

 

No acute inhalation toxicity data were identified. However, the compound is not expected to reach the lungs in appreciable quantities (based on respiratory tract deposition modelling data). Thus, inhalation will not be a significant route of exposure. Similarly, no acute dermal toxicity data were identified. However, skin contact during production and/or use is expected to be negligible.

Justification for classification or non-classification

Based on the results of the early acute oral rat study (Holbrook et al., 1975), palladium dichloride should be classified for acute oral toxicity (category 4) according to EU CLP criteria (EC 1272/2008).

 

No clear evidence of specific target organ toxicity was noted. As such, classification for STOT-SE is not considered appropriate.