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EC number: 231-753-5 | CAS number: 7720-78-7
- 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
Water solubility
Administrative data
Link to relevant study record(s)
Description of key information
Initially very soluble (>>10 g/L), rapid transformation/speciation in environmental waters and body fluids
Initial solubilities are
FeSO4: Anhydrous 228 g/L; Monohydrate 295 g/L
Key value for chemical safety assessment
Additional information
- Anon (1987). Ferrous sulphate. Dang Prop Ind Mat Rep 7:55-60.
- Lide DR ed (2002). CRC Handbook of Chemistry and Physics. 83rd edn. ISBN 0-8493-0483-0. Boca Raton, FL, U.S.A. CRC Press. 2664 p.
- Lide DR ed (2003). CRC Handbook of Chemistry and Physics. 84th edn. ISBN 0-8493-0484-9. Boca Raton, Florida, U.S.A. CRC Press. 2616 p.
- Seidell A, Link W F eds (1940). Solubilities of Inorganic and Metal Organic Compounds. 3rd edn. New York, NY, U.S.A. D Van Nostrand.
- OECD Organisation for Economic Co-operation and Development (2007). SIDS Initial Assessment Report for SIAM 24. Chemical Category: Iron Salts. Self-published, Paris, France, 17-20 April. 138 p.
- Washburn EW ed (1926). International Critical Tables of Numerical Data, Physics, Chemistry, and Technology, 1st Edition (1926-1933). Published for the National Research Council by McGraw-Hill Book Company. New York. U.S.A.
Testing for this endpoint has been waived in accordance with column 2 restrictions. All soluble iron salts dissociate in aqueous media to the respective anions and kations, and are then subject to further change of oxidation and speciated state according to the conditions. Thus the salts are not stable and undergo fast hydrolysis (DT50 < 12 h) in water, particularly if oxygen is present and the pH is in the common environmental ranges. Nonetheless a number of generally high initial water solubilities are published, which are reported in the following paragraphs. Comparably aqueous solutions are initially (i.e. before transformation/speciation) unlimitedly miscible with water and water solubility is not a relevant endpoint for them, as they are unlimitedly miscible with water.
Ferrous sulphate (FeSO4)
The most reliable value of 228 g/L at 25 ºC has been reported in the CRC handbook (Lide 2003, in agreement with Seidell et al 1940) for the anhydrous salt and 295 g/L for the monohydrate (Lide 2002), for which solubilities at elevated temperatures are available (Washburn 1926). One less reliable source states a higher value of 328 g/L (Anon 1987). The anhydrous salt and hydrated forms have thus high solubility in water.
Table: Initial water solubilities [g/L] of the registered category member salt forms
Salt |
Anhydrous form |
Solid hydrate form |
Aqueous solution |
Ferrous sulphate, FeSO4 |
228 at 25 °C |
Monohydrate (CAS 17375-41-6): 295 |
Unlimited miscibility |
Ferric and ferrous kations
The following Table below shows the maximum dissolved concentration of the iron kations in pure water as it depends upon pH (see section on Hydrolysis).
Table: Calculated maximum solubility of iron in solution at 20 °C depending on pH (OECD 2007, table 13, p 33)
pH |
Ferrous iron (II) |
Ferric iron (III) |
||
[mg Fe/L] |
[mmol/L] |
[mg Fe/L] |
[mmol/L] |
|
4 |
>1E+06 |
>1.8E+04 |
6.16E-02 |
1.1E-03 |
5 |
>1E+06 |
>1.8E+04 |
6.16E-05 |
1.1E-06 |
6 |
>1E+06 |
>1.8E+04 |
6.16E-08 |
1.1E-09 |
7 |
89600 |
1600 |
6.16E-11 |
1.1E-12 |
8 |
896 |
16 |
6.16E-14 |
1.1E-15 |
In conclusion the limit of the ferric iron kation solubility is even at significantly acidified conditions is of the order of ng Fe(III)/L.
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