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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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: 236-826-5 | CAS number: 13499-05-3
- 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
![](https://echa.europa.eu/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_environmental-fate-and-pathways.png)
Endpoint summary
Administrative data
Description of key information
Additional information
The hydrolysis of HfCl4 has been described by Kirk-Othmer in 1998, Benamira in 1997 and Beden in 1969: Hafnium tetrachloride reacts with water at room temperature, forming first hafnium oxide chloride (HfOCl2) and hydrochloric acid (HCl):
HfCl4 + 9H2O = > HfOCl2 •8H2O + 2HCl
Then, HfOCl2 reacts with H2O to give HfO2 and HCl.
To confirm this hypothesis, the hydrolysis of HfCl4 has been studied in a test complying with OECD guidance 111 and rate with reliability 1. The experiment showed that the reaction occurred immediately and the stabilization of the reaction is showed by the pH and also the chloride content, which did not vary at all after the reaction. The instantaneous hydrolysis was also seen visually with a precipitate formation that could demonstrate the formation of HfO2, a very insoluble compound.
Hf(OH)22+ is the hydrated form of HfO2 and is therefore taken into consideration for the behaviour of HfCl4 in the aquatic compartment, since HfCl4 is very hydrolytically unstable. On the contrary, this Hf(OH)22+ complex is very stable and resistant to protonation (Hagfeldt et al. 2004).
Complexes with sulphates, fluorides and chlorides may be poorly soluble in aqueous solution, but complexation with natural organic matter may increase the concentrations of Hf in natural freshwater.
Biodegradation:
Concerning degradation, HfCl4 cannot be degraded in a biotic way because it is an inorganic element.
Bioaccumulation:
Hafnium compounds in water are very insoluble, and with a strong affinity with particulate organic matter showed by high Kd value for Hf, Hf compounds and thus HfCl4 and its degradation proucts are therefore very unlikely to be bioavailable to aquatic organisms, fish and then fish-eating predators. No potential for bioaccumulation is then expected.
Adsorption:
In the terrestrial compartment, the availability of metal compounds for uptake by biota can differ from site to site and may change over time due to many processes, including weathering and (de)sorption processes. It should also be noted that Kd values are accurate only during an equilibrium state, which is difficult to reach for metals in the environment. As a consequence, part of the metal present in the solid phase may be encapsulated in the mineral fraction and is therefore not available.The IAEA Technical Reports Series No. 364 (Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments, 1994) publication reported Kd values for Hf within the range of 1500 to 5400 L/kg, with a Kd of 2500 L/kg for all soils in general.
These values and IAEA assessor were considered reliable enough to be used for HfCl4 in a read across approach, as the common metal form Hf is retrieved in soils.
The typical value was considered for assessment: Kd of 2500 L/kg. This coefficient confirmed a high adsorptivity of the substance on particulate matter and low mobility in soils, leading to a poor availability to biota via interstitial water.
Atmospheric distribution:
Volatilization can be ignored for metals compounds, except for mercury compounds and several organometallic compounds.
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.
![ECHA](/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/echa_logo.png)