Potassium Nitrate (KNO₃)
Versatile inorganic compound for agriculture, food preservatives, toothpaste and pyrotechnic applications
Overview
Potassium Nitrate (KNO₃, CAS No: 7757-79-1) is an inorganic salt widely used in both agricultural and industrial applications. It appears as white crystalline powder or granules and has high water solubility.
The combination of potassium and nitrate ions makes it an excellent nutrient source for plants. It is also used in pyrotechnics, food preservatives and toothpaste due to its oxidizing properties. Available in high purity (≥99.9%) and technical grades.
Applications
Potassium Nitrate has a wide range of uses in industrial, agricultural and consumer products:
Agricultural Fertilizers
Essential nutrient source for plants. Provides both potassium and nitrate-form nitrogen. Particularly used in fruit trees, vegetables and ornamental plants.
Food Additive (E252)
Used as a preservative in meat products. Prevents microbial growth in processed meats like sausages and salami, and provides color stability.
Toothpastes
Used to reduce tooth sensitivity. Blocks dentin tubules to alleviate hot/cold sensitivity.
Pyrotechnics
Used as an oxidizing agent in fireworks, gunpowder and other explosives. Key component in smokeless powder production.
Metal Processing
Used in cleaning metal surfaces and stainless steel production. Also serves as an additive in metal coating baths.
Solar Energy Storage
Used as a heat transfer fluid in solar energy storage systems. Offers high melting heat and thermal stability.
Technical Specifications
| Property | Value | Unit | Test Method |
|---|---|---|---|
| Chemical Name | Potassium Nitrate | - | - |
| Other Names | Saltpeter, Nitre, E252 | - | - |
| CAS Number | 7757-79-1 | - | - |
| EC No | 231-818-8 | - | - |
| Formula | KNO₃ | - | - |
| Molecular Weight | 101.10 | g/mol | - |
| Appearance | White crystalline powder or granules | - | Visual |
| Odor | Odorless | - | - |
| Purity | ≥99.9 | % | ICP |
| Moisture Content | ≤0.1 | % | Karl Fischer |
| Density | 2.11 | g/cm³ | ASTM D854 |
| Melting Point | 334 | °C | ASTM D1519 |
| Solubility (20°C) | 316 | g/L | ASTM E1148 |
| pH Value (5% sol.) | 6.0-8.0 | - | ASTM E70 |
| Chloride Content (Cl) | ≤10 | ppm | ASTM D512 |
| Heavy Metal Content (Pb) | ≤5 | ppm | ICP-MS |
Safety Information
Hazard Symbols and Statements
Oxidizer Health Hazard Environmental Hazard
Personal Protective Equipment (PPE)
- Dust-resistant gloves (nitrile or neoprene)
- Chemical goggles or face shield
- Dust mask or respirator
- 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: 15-30°C
- Keep away from flammable materials and organic substances
- Store separately from acids and reducing agents
Fire Fighting
- Suitable extinguishers: Water spray, dry chemical
- Toxic gases (nitrogen oxides) may be released during fire
- Firefighting personnel must use full respiratory protection
- Use water spray or mist in large fires
Handling and Storage
Transportation
- Ensure containers are tightly closed
- Prevent moisture contact
- Transport separately from flammable and organic materials
- Have absorbent material available for spills
- Provide adequate ventilation in transport vehicles
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 40°C
Spill Response Measures
- Evacuate exposed personnel from area
- Use appropriate personal protective equipment
- Collect spill by dry method (sweeping)
- Do not use water - solubility increases and contamination may spread
- Wipe spilled area with damp cloth
Regulatory Information
GHS Classification
- Oxidizing Solid Category 3
- Acute Toxicity (Oral) Category 4
- Eye Irritation Category 2
- Acute Aquatic Hazard Category 1
Important Regulations
- REACH: Registered
- EPA: Listed in TSCA inventory
- Food Codex: Approved as E252
- European Pharmacopoeia: Compliant
- FDA: Approved as food additive (21 CFR 172.160)
Compliance Certificates
- ISO 9001:2015 Quality Management System
- ISO 14001:2015 Environmental Management System
- Food grade certificate (E252)
- Pharmaceutical grade certificate (USP/BP/EP)
Environmental Information
Environmental Impact
Potassium Nitrate can be harmful in aquatic environments at high concentrations. Excessive nitrate loading can cause eutrophication in water sources. It occurs naturally in soil and can be degraded by microbial activity.
Biodegradation
- Water: Nitrification/denitrification by microbial activity
- Soil: Degraded by microbial activity
- Air: Not degraded by photochemical reactions
Waste Management
- Not classified as hazardous waste
- Can be disposed in licensed waste facilities
- Do not discharge to sewers or surface waters
- Dispose in accordance with local regulations
- Can be removed by biological treatment in wastewater treatment plants
Frequently Asked Questions
Why is Potassium Nitrate used in agriculture?
Potassium Nitrate contains two essential nutrients for plants (potassium and nitrate-form nitrogen). It is easily absorbed by plants, does not cause salt accumulation in soil and balances pH. It particularly improves fruit quality and increases plant resistance to diseases.
Is Potassium Nitrate safe in foods?
Yes, food-grade Potassium Nitrate (E252) is safe within certain limits. It is used as a preservative in processed meat products. Approved by FDA and EFSA. However, excessive consumption may pose health risks.
How should Potassium Nitrate be stored?
It should be stored in a dry, cool and well-ventilated place. Protect from moisture and water. Keep in original packaging, tightly closed. Should be kept away from flammable materials and organic substances.
What should I do if Potassium Nitrate 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.
What is the application rate of Potassium Nitrate in agriculture?
Application rate varies depending on plant type, soil structure and climate conditions. Generally applied between 50-300 kg/ha. In greenhouse cultivation, it can be mixed into irrigation water at 0.5-2 g/L. Soil analysis should be performed for exact dosage.