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Administrative data

Description of key information

In an acute oral toxicity study, an LD50 of greater than 4.9 g/kg bw was reported in male rats gavaged with palladium monoxide, and observed for up to 14 days (Holbrook et al., 1975).

In an acute oral toxicity study, an LD50 of greater than 4.9 g/kg bw was reported in male rats gavaged with palladium monoxide, and observed for up to 14 days (Holbrook et al., 1975).
No relevant acute dermal or inhalation toxicity data were identified, or are required at this tonnage.


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 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:
> 4 900 mg/kg bw
Based on:
test mat.
Remarks on result:
other: CL was not determined
Mortality:
Palladium salts often kill 4-10 days after administration. An LD50 of >40 mmol/kg bw, using a molecular weight of approximately 122.42 g/mol, equates to >4896.8 mg/kg bw.
Clinical signs:
No data
Body weight:
No data
Gross pathology:
No data
Other findings:
No data
Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
In an acute oral toxicity study, an LD50 of greater than 4.9 g/kg bw was reported in male rats gavaged with palladium monoxide, and observed for up to 14 days.
Executive summary:

In an acute oral toxicity study, groups of male Sprague-Dawley rats were administered palladium monoxide by stomach tube and observed for 14 days. Using the prescribed statistical method, the acute oral median lethal dose (LD50) was found to exceed 4.9 g/kg bw.

Based on the results of this study, palladium monoxide should not be classified for acute oral toxicity according to EU CLP criteria (EU 1272/2008).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
4 900 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 human acute toxicity data were identified.

 

In an acute oral toxicity study, groups of male Sprague-Dawley rats were administered palladium monoxide by stomach tube and observed for 14 days. Using the prescribed statistical method, the acute oral median lethal dose (LD50) was found to exceed 4.9 g/kg bw (equivalent to >4.2 g/kg bw as palladium, based on MWt differences). Based on the results of this study, palladium monoxide should not be classified for acute oral toxicity according to EU CLP criteria (EU 1272/2008).

No acute dermal or inhalation toxicity data were identified, or are required at this tonnage (1-10 tpa).



Justification for selection of acute toxicity – oral endpoint
Scientifically acceptable (non-guideline) study, and the only acute oral toxicity study available.

Justification for classification or non-classification

Based on the results of the available acute oral rat study, palladium monoxide does not require classification for acute oral toxicity according to EU CLP criteria (EC 1272/2008).

 

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