Registration Dossier
Registration Dossier
Data platform availability banner - registered substances factsheets
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.
The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.
Diss Factsheets
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 215-236-1 | CAS number: 1314-56-3
- 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
Description of key information
Diphosphorus pentaoxide is a hygroscopic solid which forms with moisture/water an aqueous solution of phosphorus oxyacids (primary hydrolysis) that are subject to further (secondary) hydrolysis to the end product phosphoric acid, H3PO4. The exposure to Diphosphorus pentaoxide under physiological conditions (aqueous system) will principally lead to local effects due to the strong corrosivity of the generated phosphoric acid. Consequently, the toxicity of Phosphoric acid/Diphosphorus pentaoxide, respectively is solely based on secondary effects of corrosivity.
Key value for chemical safety assessment
Additional information
Please refer to "Justification for classification or non-classification"
Justification for classification or non-classification
Diphosphorus pentaoxide is a hygroscopic solid which forms with moisture/water an aqueous solution of phosphorus oxyacids (primary hydrolysis) that are subject to further (secondary) hydrolysis to the end product phosphoric acid, H3PO4. The exposure to Diphosphorus pentaoxide under physiological conditions (aqueous system) will principally lead to local effects due to the strong corrosivity of the generated phosphoric acid. Consequently, the toxicity of Phosphoric acid/Diphosphorus pentaoxide, respectively is solely based on secondary effects of corrosivity. Therefore, the concentration of Diphosphorus pentaoxide has to be adjusted to a pH level which is tolerated in order to avoid local effects and focus on systemic impacts of the test substance. In an acute fish toxicity study (study no. FAZ13451; for details please refer to IUCLID Chapter 6.1.1) a pH of 3.19 was determined for a solution of 100 mg Diphosphorus pentaoxide/L. This concentration might be locally tolerated by the stomach tissue concerning irritating effects when given to rats via gavage repeatedly.
Taking into account the above mentioned facts, higher tier studies applying dosages greater than 100 mg Diphosphorus pentaoxide/L are scientifically and for animal welfare reasons not justified due to due to foreseeable caustic effects. Beyond this, for local irritation the concentration is in most cases the relevant parameter, and prolongation of exposure is expected to influence the severity of effect and morphology of changes, but not the NOAEC/NOAEL.
With reference to the recent OECD Guidelines for the testing of chemicals the dose volume should not exceed 20 mL/kg bw in case of aqueous solutions which leads to a maximum of 2 mg Diphosphorus pentaoxide/kg bw/d (maximum dose level of 100 mg/L).
As above mentioned Diphosphorus pentaoxide is hydrolysed to Phosphoric acid when it comes in contact with water (most common vehicle in animal studies) according to the following formula:
P2O5+ 3H2O → 2 H3PO4
This means that 2 mol Phosphate will be formed out of 1 mol Diphosphorus Pentaoxide. Diphosphorus Pentaoxide will be completely hydrolised to Phosphate when dissolved in water. With reference to the chemical parameters mentioned below the daily Phosphate uptake by a study animal (highest dose 2 mg Diphosphorus pentaoxide/kg bw/d at a maximum dose level of 100 mg/L) is calculated to be 2.7 mg Phosphate/kg bw/d
with
Molecular weight (P2O5): 142 g/mol
Molecular weight (PO43-): 95 g/mol
Max. daily dosage: 2 mg Diphosphorus pentaoxide/kg bw/d
=> (0.002g / 142 g/mol) = 1.4 x 10-5mol Diphosphorus pentaoxide/kg bw/d
=> 2 x 1.4 x 10-5mol = 2.8 x 10-5mol Phosphate/kg bw/d
=> (2.8 x 10-5mol x 95 g/mol) = 2.7 x 10-3g/kg bw/d
=>2.7 mg Phosphate/kg bw/d.
Furthermore, the mean food consumption of a rat is 100 g/kg bw/d and a rhodent standard diet contains 0.7‑0.8 % Phosphorus, the mean daily Phosphorus uptake is calculated to be 0.8 g/kg bw/d:
Mean food consumption (rat): 100 g/kg bw/d
Mean phosphorus content in rhodent diet: 0.8 %
=> (0.8 % x 100 g/kg bw/d) / 100 % = 0.8 g Phosphorus/kg bw/d
Compared to the daily uptake of 800 mg Phosphorus/kg bw/d via diet the calculated additional amount of Phosphate (2.7 mg/kg bw/d) is negligible and systemic effects are very unlikely to occur. Furthermore, no risk is arising from the Phosphate which is part of the daily diet.
Considering the above mentioned calculations/arguments a repeated dose study (regardless of the application route) is scientifically not justified since the systemic exposure to Diphosphorus Pentaoxide itself is not expected to occur due to complete dissolution to Phosphoric acid and exposure to the resulting Phosphate is negligible compared to the normal daily Phosphorus uptake via diet.
Furthermore, Phosphate is known to be a food additive and endogenous compound with widespread functions within biochemical (inter)actions. It is also a key component of numerous bio-macromolecules.
Although no sufficient data for classification of Diphosphorus pentaoxide is available, the substance is not expected to exert systemic toxic effects due to the unlikelihood of systemic exposure (strict application of risk management measures concerning the corrosivity) and the widespread occurrence in organisms of mammalians.
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.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.