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Diss Factsheets
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EC number: 234-857-9 | CAS number: 12037-29-5
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
Endpoint summary
Administrative data
Link to relevant study record(s)
Description of key information
For the purposes of human risk assessment, oral absorption of praseodymium oxide is estimated at 0.1%, inhalation absorption is estimated at 1% and dermal absorption is estimated at 0.1%.
Key value for chemical safety assessment
- Bioaccumulation potential:
- no bioaccumulation potential
- Absorption rate - oral (%):
- 0.1
- Absorption rate - dermal (%):
- 0.1
- Absorption rate - inhalation (%):
- 1
Additional information
Executive summary
Praseodymium oxide is a brown powder, with a molecular weight of 1021.4 g/mol and a melting point of 2183ºC. The D50 particle sizes for praseodymium oxide range between 2 and 50 μm. The physico-chemical properties of praseodymium oxide (sparingly soluble in water at 1.27 mg/L and with a large molecular weight >1000 g/mol) would suggest that absorption into the body by any route is likely to be extremely low.
Due to a limited availability of toxicokinetic data for praseodymium oxide, the relevant information for other soluble and poorly soluble praseodymium compounds are used to perform a qualitative assessment of the absorption, distribution/metabolism and elimination/excretion of praseodymium compounds.
Due to its very low water solubility, the absorption after oral, dermal or inhalation exposure to praseodymium oxide is expected to be very limited, as evidenced in the available oral mammalian toxicology studies where a lack of systemic adverse toxicity was demonstrated in the bolus dosing regimens up to 1000 mg/kg bw/day, the highest dose level recommended in the regulatory required repeated dose toxicity studies under REACH. The available oral gavage toxicokinetic study in mice shows a fast elimination of praseodymium oxide from the whole blood once it enters the circulatory system.
Based on the information available for soluble praseodymium compounds via intravenous or intramuscular administrations in rodents, praseodymium is distributed and deposited in the liver and bones and potentially enhances liver metabolism capacity. The incorporation in liver is expected to occur via removal of colloidal precipitates from the blood stream by phagocytic cells and consequent storage, for instance in lysosomes in the liver. Upon exposure via inhalation and under conditions of lung overload and insufficient clearance, macrophage-mediated translocation of solid material to lung-associated lymph nodes (and from there to other organs) is expected to occur. Bile is considered to be the main route of excretion. This may however be applicable to only a limited extent for praseodymium oxide since its absorption after oral, dermal or inhalation exposure is expected to be minimal.
For the purposes of human risk assessment, oral absorption of praseodymium oxide is estimated at 0.1%, inhalation absorption is estimated at 1% and dermal absorption is estimated at 0.1%.
The full toxicokinetic report is attached in section 13 of this dataset.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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