Diammonium Phosphate (DAP)
Diammonium Phosphate (DAP) is a highly water-soluble, white crystalline fertilizer containing nitrogen and phosphorus. It is one of the most widely used phosphate fertilizers globally, providing a balanced source of nutrients essential for plant growth. DAP supplies ammonium nitrogen (NH₄⁺) and phosphate (PO₄³⁻), which promote vigorous root development, improve soil fertility, and enhance crop yield and quality. Besides agriculture, DAP serves important roles in food additives, fire retardants, and industrial applications. It’s favored for its high nutrient content, ease of application, and compatibility with other fertilizers and soil amendments.
Diammonium Phosphate (DAP) Uses
Primary Uses
- Agriculture & Horticulture
- Fertilizer: DAP is predominantly used as a phosphorus and nitrogen fertilizer for a wide range of crops including cereals (wheat, rice, corn), legumes, vegetables, fruits, and turfgrass. Its high nutrient concentration promotes early root development and improves plant vigor.
- Soil Amendment: Improves soil nutrient balance, especially in phosphorus-deficient soils.
- Starter Fertilizer: Applied as a starter fertilizer at planting to supply essential nutrients during early crop growth stages.
- Foliar Application: Sometimes used in soluble form for foliar feeding to correct nutrient deficiencies.
- Animal Feed Supplement
- Added in small amounts to animal feed as a source of phosphorus and ammonium, aiding in animal nutrition.
- Food Industry
- Food Additive: Serves as an acidity regulator, nutrient supplement, and yeast nutrient in baking and brewing processes.
- Yeast Growth Promoter: Enhances fermentation efficiency in brewing by providing essential nutrients.
- Industrial Applications
- Fire Retardants: Used as a flame retardant additive in wood products, textiles, and paper to reduce flammability.
- Corrosion Inhibitor: Acts as a corrosion inhibitor in metal treatment and water conditioning.
- Water Treatment: Occasionally used in water treatment processes for phosphate supplementation and corrosion control.
Secondary Uses
- Pharmaceuticals
- Used as a buffering agent and nutrient in pharmaceutical formulations and fermentation processes.
- Laboratory Reagent
- Employed in chemical analyses, buffer preparations, and fermentation studies.
- Miscellaneous Industrial Uses
- Used in detergent formulations as a builder and water softener.
- Component in fertilizers blends and specialty nutrient mixtures for controlled-release formulations.
- Basic Identification Attributes
- Chemical Name (IUPAC): Diammonium hydrogen phosphate
- Common/Trade Name: Diammonium Phosphate (DAP)
- CAS Number: 7783-28-0
- HS Code: 3105.30.00
- Molecular Formula: (NH₄)₂HPO₄
- Synonyms:
- Diammonium hydrogen phosphate
- Ammonium phosphate, dibasic
- DAP fertilizer
- Physical & Chemical Properties
- Physical State: White crystalline granules or powder
- Odor: Odorless
- Solubility: Highly soluble in water (~370 g/L at 20°C)
- Melting Point: Decomposes at approx. 190°C
- pH (1% aqueous solution): Slightly alkaline (~7.5–8.0)
- Density: ~1.8 g/cm³ (bulk density varies)
- Stability: Stable under normal conditions; hygroscopic (absorbs moisture)
- Safety & Hazard Attributes
- Hazard Class (GHS): Generally non-hazardous; irritant if dust inhaled
- Toxicity: Low toxicity; ingestion in large quantities may cause irritation
- Reactivity: Stable; incompatible with strong acids and alkalis
- Handling Precautions: Avoid inhaling dust; use dust masks and gloves
- Storage & Handling Attributes
- Storage Conditions: Store in a cool, dry, well-ventilated place away from moisture and incompatible substances
- Container Type: Bags or bulk containers with moisture barrier
- Shelf Life: 2–3 years if stored properly
- Handling Precautions: Use PPE to avoid dust inhalation and skin contact
- Regulatory & Compliance Attributes
- Regulatory Status: Approved fertilizer and food additive by most global regulatory bodies
- Transportation: Non-hazardous material; follow standard transport guidelines for fertilizers
- Environmental Compliance: Compliant with environmental norms regarding phosphorus use
- Environmental & Health Impact
- Biodegradability: Not applicable (inorganic salt)
- Ecotoxicity: Excessive use can lead to eutrophication of water bodies; responsible application required
- Bioaccumulation: Not applicable
Carcinogenicity/Mutagenicity: Not classified as hazardous
Safety Handling Precautions
- PPE Required:
- Dust mask or respirator when handling bulk powder or granules
- Safety goggles
- Gloves (nitrile or latex)
- Protective clothing
- Handling Guidelines:
- Avoid dust generation and inhalation
- Use in well-ventilated areas
- Prevent moisture contact to avoid caking
- Storage Measures:
- Keep containers tightly sealed
- Store away from incompatible materials such as strong acids
First Aid Measures
- Inhalation: Move to fresh air; seek medical attention if respiratory irritation occurs
- Skin Contact: Wash with soap and water; seek medical advice if irritation develops
- Eye Contact: Rinse eyes thoroughly with water for at least 15 minutes; seek medical care if irritation persists
- Ingestion: Rinse mouth; drink water; seek medical attention if large amounts swallowed
Firefighting Measures
- Fire Hazards: Non-flammable; may decompose at high temperatures releasing ammonia and phosphorus oxides
- Extinguishing Media: Use water spray, foam, dry chemical, or CO₂ as appropriate for surrounding fire
- Special Precautions: Wear full protective gear and self-contained breathing apparatus if involved in fire
- Decomposition Products: Ammonia, nitrogen oxides, phosphorous oxides