CALCIUM HYDROGEN SULPHITE

Calcium Hydrogen Sulphite is an inorganic salt, commonly used as a reducing agent, preservative, and intermediate in industrial and chemical processes.
Calcium Hydrogen Sulphites general formula is Ca(HSO₃)₂.
Calcium Hydrogen Sulphite belongs to the class of sulfite/bisulfite salts.

CAS Number: 13780-03-5
Molecular Formula: CaH4O3S
Molecular Weight: 124.17
EINECS Number: 237-423-7

Synonyms: CALCIUM BISULFITE, Calcium hydrogen sulfite, Calcium hydrogensulphite, Sulfurous acid calcium salt (2:1), Sulfurous acid calcium salt (2:1), CALCIUM HYDROGEN SULPHITE, calcium hydrogen sulfite, Calcium sulfite Ca(HSO3)2, Calciumhydrogensulfit, calcium bis(hydrogen sulfite), calcium hydrogen sulfite, calcium hydrogensulphite;CALCIUMMETABISULPHITE;CALCIUMBISULPHITE;Calcium hydrogensulfite;Calcium bisulfite;Bis(sulfinooxy)calcium;CALCIUMBISULFITE(SOLUTION)

Calcium Hydrogen Sulphite consists of calcium ions (Ca²⁺) and hydrogen sulfite (HSO₃⁻) ions.
The bisulfite ion exhibits reducing and nucleophilic behavior.
This enables participation in various chemical reactions.

Calcium Hydrogen Sulphite is typically found as an aqueous solution rather than a solid, due to its instability in dry form.
It appears as a clear to slightly cloudy liquid.
Calcium Hydrogen Sulphite has a characteristic sulfur dioxide-like odor.

Calcium Hydrogen Sulphite exhibits reducing properties, meaning it can donate electrons in reactions.
Calcium Hydrogen Sulphite reacts readily with oxidizing agents.
This is important in industrial applications.

Calcium hydrogen sulphite can release sulfur dioxide (SO₂) under acidic or heated conditions.
This contributes to its reactivity and preservative action.
Calcium Hydrogen Sulphite must be handled carefully.

Calcium Hydrogen Sulphite is chemically unstable, especially when exposed to air, heat, or strong acids.
It can decompose or oxidize to form sulfates.
Calcium Hydrogen Sulphite proper storage is necessary.

Calcium Hydrogen Sulphite is used in industrial processing, water treatment, and chemical synthesis.
It participates in bleaching and preservation processes.
This highlights its practical importance.

Calcium Hydrogen Sulphite is best described as a reactive inorganic bisulfite salt used as a reducing agent and preservative, especially in aqueous industrial systems.
Calcium Hydrogen Sulphite is an inorganic compound which is the salt of a calcium cation and a bisulfite anion. 
Calcium Hydrogen Sulphite may be prepared by treating lime with an excess of sulfur dioxide and water. 

As a food additive it is used as a preservative under the E number E227. 
Calcium Hydrogen Sulphite is an acid salt and behaves like an acid in aqueous solution. 
Calcium Hydrogen Sulphite is used in the sulfite process for producing paper from wood chips.[1]

Density    about: 1.06
solubility: soluble in H2O
LogP: -1.591 (est)

Calcium Hydrogen Sulphite, Ca(HS03)2 is a compound known only in solution. 
The colorless aqueous solution smells like sulfur dioxide and is made by dissolving calcium sulfite in aqueous S02 solution, or by passing S02 through calcium hydroxide suspensions. 
Calcium Hydrogen Sulphite is used in large amounts to make cellulose by the sulfite process, it is also used to disinfect barns, as an antiseptic in medicine, and as a preservative.

Calcium Hydrogen Sulphite can be prepared by treating lime (chemical formula Ca(OH)2) with an excess of sulfur dioxide and water.
Upon synthesis of calcium bisulfite solution, it will have a green to yellow opaque appearance as an aqueous solution.

Calcium hydrogen sulphite (calcium bisulfite) is typically formed by absorbing sulfur dioxide (SO₂) into a calcium-containing solution, such as calcium hydroxide.
This produces a bisulfite-rich aqueous solution.
Calcium Hydrogen Sulphite is commonly prepared in situ.

Calcium Hydrogen Sulphite exists mainly in equilibrium with dissolved sulfur dioxide and sulfite species in solution.
Its composition can shift depending on pH and temperature.
This affects its reactivity.

Calcium hydrogen sulphite exhibits moderate acidity due to the presence of the HSO₃⁻ ion.
It can act as both an acid and a reducing agent.
This dual behavior is important in reactions.

Calcium Hydrogen Sulphite shows strong affinity for oxygen, making it effective in oxygen scavenging processes.
It can prevent oxidation in systems.
This is useful in preservation and treatment.

Calcium Hydrogen Sulphite can participate in addition reactions with aldehydes and ketones, forming bisulfite adducts.
This is used in purification and separation processes.
Calcium Hydrogen Sulphite is a classical chemical application.

Calcium Hydrogen Sulphite demonstrates bleaching properties, particularly in pulp and textile processing.
It can reduce colored compounds.
This improves material appearance.

Calcium hydrogen sulphite is highly soluble in water, existing mainly as ions in solution.
Calcium Hydrogen Sulphite does not form stable solid crystals under normal conditions.

Calcium Hydrogen Sulphite can gradually oxidize to calcium sulfate or sulfite upon exposure to air.
This reduces its effectiveness over time.
Calcium Hydrogen Sulphite is a dynamic, aqueous bisulfite system with reducing, bleaching, and oxygen-scavenging properties, widely used in industrial and chemical processes.

Uses Of Calcium Hydrogen Sulphite:
As germicide, preservative, and disinfectant; for washing (1:1000) casks in brewing to prevent souring and cloudiness of beer and to prevent secondary fermentation; as antichlor in bleaching fabrics; largely in manufacture of sulfite cellulose from wood for paper-making.
Calcium Hydrogen Sulphite is widely used in the pulp and paper industry for chemical pulping processes.
It helps break down lignin in wood.

In water treatment systems, it acts as an oxygen scavenger and reducing agent.
Calcium Hydrogen Sulphite removes dissolved oxygen from water.
This helps prevent corrosion in pipelines and boilers.

Calcium Hydrogen Sulphite is used in food and beverage processing as a preservative and antioxidant (in controlled applications).
It inhibits microbial growth and oxidation.
Calcium Hydrogen Sulphite is applied in textile processing as a bleaching and decolorizing agent.

Calcium Hydrogen Sulphite helps remove unwanted color from fabrics.
This improves material appearance.
In chemical synthesis, it is used as a reducing agent and intermediate.

Calcium Hydrogen Sulphite participates in reactions involving sulfur chemistry.
This supports industrial production.
It is used in leather processing for dehairing and preservation.

Calcium Hydrogen Sulphite helps modify protein structures and prevent degradation.
This improves processing efficiency.
In gas treatment systems, it is used to absorb and neutralize sulfur dioxide.

Calcium Hydrogen Sulphite helps control emissions.
This supports environmental management.
Calcium hydrogen sulphite is also applied in photographic and imaging processes (historically) as a reducing and stabilizing agent.

Calcium Hydrogen Sulphite helps control chemical reactions.
This supports image development.
Calcium Hydrogen Sulphite is used wherever reducing action, oxygen removal, bleaching, and preservation are required, especially in pulp processing, water treatment, textiles, and chemical industries.

Calcium hydrogen sulphite (calcium bisulfite) is used in boiler water treatment systems to remove dissolved oxygen and prevent corrosion.
Calcium Hydrogen Sulphite protects metal surfaces from oxidative damage.
This improves equipment lifespan.

In industrial cleaning and descaling formulations, it acts as a reducing agent to remove oxidized deposits.
Calcium Hydrogen Sulphite helps break down scale and residues.
This improves cleaning efficiency.

Calcium Hydrogen Sulphite is applied in dye and pigment processing as a decolorizing and reducing agent.
It helps control color intensity and remove unwanted shades.
This improves product consistency.

In agricultural applications, it may be used in certain formulations to control microbial growth or oxidation.
Calcium Hydrogen Sulphite helps stabilize solutions.
This supports product effectiveness.

Calcium hydrogen sulphite is used in oil and gas industry systems as an oxygen scavenger.
Calcium Hydrogen Sulphite protects pipelines and storage systems from corrosion.
This enhances operational reliability.

Calcium Hydrogen Sulphite is applied in chemical purification processes, especially for forming bisulfite addition compounds with aldehydes.
This allows selective separation of compounds.
This supports fine chemical production.

In fermentation and biochemical processes, it may be used to control oxidation or microbial activity.
Calcium Hydrogen Sulphite helps maintain process conditions.
This improves process stability.

Calcium Hydrogen Sulphite is also used in smoke and emission control systems as a reducing agent.
It helps neutralize sulfur-containing gases.
Calcium Hydrogen Sulphite is used wherever oxygen scavenging, reduction, bleaching, and stabilization are required across water treatment, industrial processing, environmental control, and chemical synthesis.

Safety Profile Of Calcium Hydrogen Sulphite:
A poison via ingestion, strong irritant via skin and eye contact, ingestion, and inhalation. 
Spontaneously combukible when heated to decomposition it emits toxic fumes of SOx.

Calcium Hydrogen Sulphite presents moderate hazards, mainly due to its ability to release sulfur dioxide (SO₂), acidity, and reducing properties.
Calcium Hydrogen Sulphite requires careful handling, especially in solution form.
Proper safety measures are essential.

Skin contact may cause irritation, particularly with prolonged exposure to concentrated solutions.
Symptoms can include redness or discomfort.
Protective gloves are recommended.

Eye contact can cause moderate to severe irritation.
Symptoms include redness, pain, and watering.
Immediate rinsing with plenty of water is necessary.

Inhalation is a significant hazard, especially due to released sulfur dioxide gas.
SO₂ can cause respiratory irritation, coughing, and breathing difficulty.
High exposure may lead to serious respiratory effects.

Ingestion is harmful and may cause gastrointestinal irritation and systemic effects.
It may lead to nausea, vomiting, or discomfort.
Calcium Hydrogen Sulphite is not flammable, but it can decompose when heated or acidified.