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Diss Factsheets
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EC number: 231-635-3 | CAS number: 7664-41-7
- 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
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Phototransformation in air
Administrative data
Link to relevant study record(s)
Description of key information
Ammonia does not absorb at wavelengths >290 nm and, therefore, is not expected to be susceptible to direct photolysis by sunlight. Ammonia may be photolytically dissociated at wavelengths of less than 222nm, resulting in the production of amino and ammonia radical species. The gas phase reaction of ammonia with photochemically produced hydroxyl radicals is thought to contribute about 10% to the overall atmospheric removal process.
In the atmosphere, ammonia can be removed by rain or snow washout. Reactions with acidic substances, such as H2SO4, HCl, HNO3, or N oxides (all produced in high concentrations from anthropogenic activities) produce ammonium aerosols, which can undergo dry or wet deposition. The gas phase reaction of ammonia with photochemically produced hydroxyl radicals is thought to contribute about 10% to the overall atmospheric removal process. The best estimate of the half-life of atmospheric ammonia is a few days (ATSDR; Toxicological Profile for Ammonia. Atlanta, GA: Agency for Toxic Substances and Disease Registry, US Public Health Service (2004)).
Key value for chemical safety assessment
Additional information
Ammonia reacts with ozone, hydroxyl radical, and atomic oxygen. Oxidation by ozone is a first order reaction with respect to the concentration of ammonia and is catalyzed by hydroxide ions over the pH range 7-9. Ammonia and ozone react to produce ammonium nitrate aerosols. Photolytic degradation and reaction with photolytically produced hydroxyl radicals (·OH) in the troposphere are major pathways for the removal of atmospheric ammonia. Some of the ammonium in the atmosphere is oxidized to oxides of the nitrogen and nitrate ion, which represents a significant contribution to the total acidity of rainfall. Various ammonium complexes may also be formed by the heterogeneous reaction of atmospheric ammonia with nitric oxide-soot surfaces in the atmosphere. There are two primary photochemical reactions that destroy ammonia in the atmosphere. Ammonia may be photolytically dissociated at wavelengths of less than 222nm, resulting in the production of amino and ammonia radical species. The second reaction is a thermal anhydrous reaction between ammonia and sulphur dioxide resulting in the formation of ammonium sulphate aerosols.
The kinetic behavior of OH radicals in the presence of a large excess of NH3 was studied by pulsed photolysis. OH radicals were produced by vacuum-uv photolysis of H2O and were monitored by resonance fluorescence. The rate constant for the reaction of OH with NH3was determined to be 1.5(±0.4) x 10-13cm3molecules-1s-1at 25°C.
The photodegradation of ammonia was investigated using a flash photolysis system. The rate constant for the photodegradation of ammonia under the conditions of this study is reported to be 1.47 (±0.7) x 10-13cm³ molecule-1s-1at 25°C.
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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