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Diss Factsheets
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EC number: 213-607-2 | CAS number: 993-13-5
- 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
Dissociation constant
Administrative data
Link to relevant study record(s)
- Endpoint:
- dissociation constant
- Type of information:
- experimental study
- Adequacy of study:
- weight of evidence
- Reliability:
- 4 (not assignable)
- Rationale for reliability incl. deficiencies:
- secondary literature
- Qualifier:
- no guideline followed
- Principles of method if other than guideline:
- No details provided how the endpoint was measured.
- GLP compliance:
- not specified
- Dissociating properties:
- yes
- No.:
- #1
- pKa:
- 2.38
- Temp.:
- 25 °C
- Conclusions:
- The dissociation constant for MPA was reported to be 2.38 at 25 °C.
Reference
Description of key information
In 1953 Crofts and Kosolapoff published two dissociation constant values for methyl phosphonic acid that have been reviewed by Kingery and Allan in 1995. Crofts and Kosolapoff published a pKa of 2.38 and 7.74. Harris et al. published also two dissociation constant values at pKa of 2.2 and 7.7 in 1964, that have been also reviewed by Kingery and Allan in 1995. Serjant and Dempsey published pKa values of 2.12 and 7.29 in 1979 and Munro et al. published a pKa of 2.38 at 25 °C in 1999. Taking these data together it seems that the slight differences observed in the lower dissociation constant might be due to different temperatures these constants were measured. Since in most cases temperatures are not reported it is difficult to estimate the pKa value at 20 °C. Therefore the value of 2.12 is used for the temperature of about 20 °C, assuming that this value was measured at a room temperature of about 20 °C.
Key value for chemical safety assessment
- pKa at 20°C:
- 2.12
Additional information
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.