Sodium Nitrate

Sodium Nitrate is used as a food additive (preservative) and color fixative in cured meats and poultry. IT also has a role in fertiliser production for the agricultural industry. Also used in wastewater applications where consuming the nitrate in preference to oxygen, enabling water treatment. It is used as an anticaking agent.

Synonyms
Chile Saltpeter, NaNO3, Nitric Acid, Sodium Salt, Nitric Acid, Sodium Salt 1 : 1, Soda Niter Chile Saltpeter, Sodium Nitrate
Chemical Formula
NaNO3
CAS Number
7631-99-4

Characteristics

Molar Weight
84.9947 g/mol
Melting Point
308 °C
Boiling Point
380 °C
Density
2.26 g/cc
Forms
Powder, White, Prill, Granular, Pellets

Uses and applications

Key applications

  • Food additive
  • Water treatment
  • Cleaning products
  • Glass
  • Adhesives and Sealants
  • Metal finishing
  • Agricultural
  • Building & Construction products

Sodium nitrate

Sodium nitrate (NaNO3) is the sodium salt of nitric acid and occurs naturally primarily as the mineral nitratein (Chile saltpetre). Large natural deposits are traditionally found in the Atacama Desert in Chile and Peru. Today, sodium nitrate is mainly produced synthetically, as this is more cost-effective and less dependent on natural deposits.

Properties of sodium nitrate

Sodium nitrate is a colourless, odourless, crystalline solid that dissolves very well in water and has a hygroscopic effect. When heated, sodium nitrate decomposes – at around 380 °C, sodium nitrite (NaNO2) is formed, and at higher temperatures above 800 °C, sodium oxide (Na2O) is formed.
Industrial production is mainly carried out by neutralising nitric acid with sodium carbonate or sodium hydroxide. This synthetic production method has almost completely replaced the former extraction from Chilean deposits.

Sodium nitrate in the food industry

Sodium nitrate is used in the food and beverage industry as additive E 251 and serves to preserve and stabilise the colour of meat and sausage products. Typical applications are:
  • Preservation of meat and sausage products, as sodium nitrate inhibits bacteria such as Clostridium botulinum, which could otherwise form botulinum toxin.
  • Preserving the red colour of meat, as sodium nitrate supports the formation of nitrosomyoglobin via intermediate products.
  • Use in cheese and fish products to prevent spoilage and preserve freshness for longer.

Sodium nitrate in agriculture

Sodium nitrate is used in agriculture as a mineral nitrogen fertiliser and provides plants with immediately available nitrate nitrogen. The most important applications include:
  • Rapid nitrogen supply, which promotes rapid growth.
  • Use in soils with low nutrient availability, as nitrate is immediately available to plants.

Sodium nitrate in the glass industry

In glass production, sodium nitrate acts as an oxidising agent, clarifying agent and process aid to improve glass quality. Typical areas of application include:
  • Removal of unwanted impurities such as iron or sulphur compounds in the glass melt.
  • Reducing gas bubbles and cloudiness to increase the transparency and homogeneity of the glass.
  • Modifying specific glass properties such as heat resistance or optical purity.
  • Chemical tempering of glass, for example in smartphone displays or safety glass.

Sodium nitrate in the pharmaceutical industry

Sodium nitrate is used in the pharmaceutical sector as an excipient, oxidation reagent and component of various pharmaceutical formulations. Its most important applications include:
  • Improving the solubility and stability of active ingredients in tablets.
  • Use as an oxidising agent in the manufacture of certain drugs and analytical methods.
  • Production of organic nitrates, which are used in heart medications as vasodilators.
  • Use as an antimicrobial ingredient in creams, ointments and antiseptic formulations.
Young woman applying essential oil on her face sitting on the sofa in the living room at home GettyImages-2212603175.jpg

Sodium nitrate in the cosmetics industry

In cosmetic products in the personal care industry, sodium nitrate serves as a preservative, pH regulator and functional additive. Examples of applications include:
  • Protection against microbial contamination in creams, lotions and liquid formulations.
  • pH stabilisation to improve skin compatibility.
  • Use in hair dyes and bleaches to support oxidative reactions.
  • Stabilising effect in skin and hair care products as well as decorative cosmetics.

Further areas of application for sodium nitrate

Sodium nitrate in water treatment

Sodium nitrate plays an important role in biological and technical water treatment systems. Key applications include:
  • Denitrification in sewage treatment plants, where microorganisms convert nitrate into gaseous nitrogen.
  • Use as an oxygen substitute in anaerobic systems to prevent the formation of hydrogen sulphide.
  • Corrosion protection in cooling water systems by stabilising the chemical environment.
  • Stabilisation of irrigation and drinking water systems to prevent nutrient imbalances.

Sodium nitrate in the cleaning industry

Sodium nitrate is used in the hygiene industry in cleaners and degreasers as an oxidising agent and process enhancer. Typical applications are:
  • Removal of organic contaminants from metal, plastic and glass surfaces.
  • Use in drain cleaners to dissolve grease and hair deposits.
  • Protection of sensitive metal surfaces through controlled oxidation processes.
  • Supporting the degreasing of machines, pipes and industrial plants.
  • Use in disinfectants and sterilisants to reduce germs.

Sodium nitrate in the construction industry

In construction chemistry, sodium nitrate is used as an additive for concrete and as an oxidising agent and stabiliser. The most important areas of application are:
  • Accelerating the hardening of concrete at low temperatures.
  • Protecting metal components from corrosion by inhibiting harmful oxidation processes.
  • Component of explosives for tunnel construction and rock blasting.
  • Stabilisation of loose soils to reduce dust formation.

Sodium nitrate in the energy industry

Sodium nitrate is used in the energy sector for heat storage, oxidation processes and in fuels. Relevant areas of application include:
  • Heat storage in solar thermal systems through use in liquid salt mixtures.
  • Use as an oxidising agent in explosives for mining and oil extraction.
  • Component of oxidising components in rocket fuels.
  • Potential use in sodium-ion batteries as an alternative to lithium systems.

Sodium nitrate in the lubricant industry

Sodium nitrate acts as a stability and protective additive in lubricants. Typical applications include:
  • Improving the temperature and oxidation resistance of industrial and motor oils.
  • Protection against corrosion in machines and equipment.
  • Increasing lubricant life by reducing ageing processes.

Sodium nitrate in the polymer industry

In plastics processing, sodium nitrate is a functional additive in polymerisation processes and material optimisation. Areas of application include:
  • Use as an oxidising agent in polymerisation reactions.
  • Use as a pore former in filter materials and foams.
  • Increasing the thermal and oxidative stability of high-performance plastics.
  • Functioning as a flame retardant additive in flame-retardant plastics.

Sodium nitrate in the adhesive and sealant industry

Sodium nitrate is used as a stability and functional additive in adhesives and sealants. Typical applications include:
  • Stabilisation against undesirable decomposition or polymerisation processes during storage.
  • Acceleration of curing in high-performance adhesives.
  • Use as a pore former in sound and heat-insulating adhesives.
  • Function as a flame retardant and corrosion protection additive in construction, automotive and electronics applications.

Other areas of application

Applications in metal finishing include use as a pickling and oxidising agent to improve the surface quality and corrosion resistance of aluminium, stainless steel and copper.
In the rubber industry, sodium nitrate is used, among other things, as a vulcanisation accelerator, flame retardant additive and pore former. It improves the elasticity, durability and oxidation resistance of rubber products.

Summary

Sodium nitrate (NaNO3) is a versatile inorganic salt that plays a key role in numerous industrial sectors. Thanks to its oxidising, stabilising and process-active properties, it plays an important role in food processing, agriculture, the glass and pharmaceutical industries, cosmetics, water treatment, cleaning technology, construction chemicals, energy technology, lubricant and polymer production, and in the adhesives and sealants industry.
Sodium nitrate serves as a preservative and oxidising agent as well as an auxiliary material, stabiliser, nutrient source, reaction partner and additive in technical and biological processes. Thanks to its broad functionality, sodium nitrate contributes to quality and process stabilisation, improves material properties and increases the efficiency of industrial applications.