Sodium Nitrite (NaNO₂)

Overview

Sodium Nitrite (NaNO₂, CAS No: 7632-00-0) is an inorganic salt appearing as white or slightly yellowish crystalline powder. It finds widespread use as a preservative in the food industry (E250), as a corrosion inhibitor in metal industries and as an important reagent in chemical syntheses.

Sodium nitrite has high water solubility (82 g/100 mL at 20°C) and is hygroscopic. It is an oxidizing agent and can react with organic materials. In food applications, it prevents the growth of botulism bacteria in meat products and imparts the characteristic pink color.

Applications

Sodium Nitrite has a wide range of industrial and commercial applications:

Technical Specifications

Safety Information

Hazard Symbols and Statements

Toxic Oxidizing Environmental Hazard

Personal Protective Equipment (PPE)

• Chemical-resistant gloves (nitrile or neoprene)
• Chemical goggles or face shield
• Dust mask or respirator (when working with powder)
• Lab coat or protective clothing
• Chemical-resistant shoes

Storage Conditions

• Store in a cool, dry and well-ventilated place
• Keep in original packaging, tightly closed
• Storage temperature: 15-25°C
• Keep away from flammable materials and organic substances
• Avoid contact with acids (may release toxic nitrous gases)

Fire Fighting

• Suitable extinguishers: Water spray, dry chemical powder
• Toxic nitrogen oxide gases may be released during fire
• Firefighting personnel must use full respiratory protection
• Use water spray or mist in large fires, avoid direct water jet

Handling and Storage

Transportation

• Ensure containers are tightly closed
• Prevent moisture contact
• Transport separately from flammable and organic materials
• Do not transport with acids in the same vehicle
• Have absorbent material available for spills

Storage

• Store in dry, cool and well-ventilated areas
• Display appropriate signage in storage area
• Protect from direct sunlight
• Store on elevated shelves
• Storage temperature should not exceed 30°C

Spill Response Measures

• Evacuate exposed personnel from area
• Use appropriate personal protective equipment
• Collect spill by dry method (sweeping)
• Do not use water - may react
• Wash spilled area with plenty of water (after neutralization if necessary)

Regulatory Information

GHS Classification

• Acute Toxicity (Oral) Category 3
• Acute Toxicity (Dermal) Category 3
• Acute Toxicity (Inhalation) Category 2
• Methemoglobin Formation Category 1
• Oxidizing Solid Category 2
• Acute Aquatic Hazard Category 1

Important Regulations

• REACH: Registered
• EPA: Listed in TSCA inventory
• European Food Additives Regulation: Approved as E250
• FDA: Approved for certain food applications (21 CFR 172.175)
• Food Codex: Maximum permitted 150 mg/kg in meat products

Compliance Certificates

• ISO 9001:2015 Quality Management System
• ISO 22000:2018 Food Safety Management System
• GMP (Good Manufacturing Practices)
• Food grade certificate (for specific batches)

Environmental Information

Environmental Impact

Sodium nitrite is highly toxic in aquatic environments. It is severely harmful to aquatic life at high concentrations. It may also have adverse effects on soil microorganisms. Nitrite ions can cause oxygen depletion in water systems, leading to eutrophication.

Biodegradation

• Oxidized to nitrate by microbial activity
• Water: Nitrite ions naturally oxidize to nitrate
• Soil: Converted to nitrate by microbial activity
• Air: Decomposed by photochemical reactions

Waste Management

• Classified as hazardous waste
• Must be disposed in licensed hazardous waste facilities
• Do not discharge to sewers or surface waters
• Dispose in accordance with local regulations
• Chemical treatment required in wastewater treatment plants

Frequently Asked Questions

Why is sodium nitrite used in meat products?

Sodium nitrite is used in meat products for two main purposes: 1) It prevents the growth of Clostridium botulinum bacteria that produce botulism toxin, 2) It imparts the characteristic pink color to cured meats (nitrosomyoglobin formation). It also prevents oxidation, extending shelf life.

What are the usage limits of sodium nitrite in foods?

According to the Turkish Food Codex, the maximum permitted sodium nitrite in meat products is 150 mg/kg (100 mg/kg as nitrite ion). In practice, it is usually used in the range of 80-120 mg/kg. Limits vary depending on product type and processing method.

How should sodium nitrite be stored?

Sodium nitrite should be stored in a dry, cool and well-ventilated place. Protect from moisture and water. Keep in original packaging, tightly closed. Storage temperature should be between 15-25°C. Do not store with acids or flammable materials.

What should I do if sodium nitrite contacts skin?

Remove contaminated clothing immediately and wash skin with plenty of water and soap for at least 15 minutes. Seek medical attention if irritation persists. In case of eye contact, rinse eyes with plenty of water for at least 15 minutes and seek medical attention urgently. If swallowed, do not induce vomiting and seek immediate medical help.

What is the difference between sodium nitrite and sodium nitrate?

Sodium nitrite (NaNO₂) and sodium nitrate (NaNO₃) are different chemical compounds. The nitrite (NO₂⁻) ion is more reactive than the nitrate (NO₃⁻) ion and is used in lower concentrations in foods. Nitrite exhibits direct antimicrobial effect, while nitrate becomes effective after microbial conversion to nitrite.