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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 228-601-5 | CAS number: 6303-21-5
- 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
Storage stability and reactivity towards container material
Administrative data
Link to relevant study record(s)
Description of key information
Metal Corrosivity of Hypophosphorous Acid was assessed by tests which were carried out according to the UN Classification Procedure, Test Methods and Criteria Relating to Substances of Class 8, Test C.1. (http://live.unece.org/fileadmin/DAM/trans/danger/publi/manual/Rev5/English/03en_part3.pdf pp385-388)
Approximately 1 litre of 50% hypophosphorous acid was charged to a 2 litre jacketed glass vessel fitted with reflux condenser and heated using an external Haake oil heater/circulator. Three pre-weighed test coupons were suspended by PTFE tape such that one was fully immersed in the liquid, one half-immersed and the other suspended in the vapour space above the liquid surface. Separate tests were run for aluminium and steel coupons. The vessel was heated at 55°C for 7 days, after which the coupons were washed in water, all loose deposits removed with a plastic brush, rinsed with acetone, dried and re-weighed.
According to the results; Steel showed a maximum uniform corrosion rate of 55.22mm/year on the fully immersed coupon, which is far in excess of the 6.25mm/year threshold for classification as corrosive. Aluminium showed no uniform corrosion, but exhibited localized corrosion with a maximum intrusion depth of 140μm which exceeds the threshold of 120μm for classification as corrosive.
According to CLP the classification of the substance is to be considered as H290: May be corrosive to metals.
Additional information
The steel coupons showed a maximum corrosion rate of 55.22mm/year based on the fully immersed coupon. Vigorous effervescence from wetted surfaces was observed immediately on contact with the HPA solution. The effervescence gradually subsided and had ceased after four days immersion. All immersed surfaces were substantially corroded away by the end of the test period. The non-immersed part of the half-immersed coupon developed a remarkable “fan-like” encrustation emanating from the water line. The liquor became cloudy with a large amount of grey sediment and a strong phosphine-like odour.
The aluminium coupons also showed effervescence from wetted surfaces immediately on immersion, though less vigorous than the steel. As with steel, the effervescence gradually subsided and had ceased after four days immersion. None of the coupons exhibited weight loss, and a small gain in weight of the immersed coupons was measured. However, the immersed surfaces were blackened and exhibited localized blistering and flaking. The test protocol specifies that when corrosion is localized instead of uniform the depth of the deepest intrusion is used to determine the classification. For an immersion period of seven days the threshold is an intrusion depth of at least 120μm (0.12mm). The thickness of the coupons was measured using a micrometer placed across the corroded and non-corroded parts of each coupon.
According to the results; Steel showed a maximum uniform corrosion rate of 55.22mm/year on the fully immersed coupon, which is far in excess of the 6.25mm/year threshold for classification as corrosive. Aluminium showed no uniform corrosion, but exhibited localized corrosion with a maximum intrusion depth of 140μm which exceeds the threshold of 120μm for classification as corrosive.
According to CLP the classification of the substance is to be considered as H290: May be corrosive to metals.
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.