Monoammonium phosphate

Monoammonium phosphate (CAS 7722-76-1), commonly known as MAP or designated E342 in food applications, is an inorganic ammonium salt used industrially as a flame retardant and pH buffering agent.

Where is Monoammonium phosphate used?

• Agriculture: high-analysis fertilizer applied directly to soil
• Fertigation: dissolved to supply phosphorus and nitrogen in plant-available form
• Textiles, paper and cellulosic materials: flame retardant that interrupts combustion at the fiber level
• Construction: intumescent coatings and fire-retardant board treatments requiring controlled char formation
• Leather processing and industrial manufacturing: buffer solutions and pH adjustment
• It delivers both nitrogen and phosphorus in a single compound.
• Component of ABC powder in some fire extinguishers.
• Crystals are widely used in optics due to birefringence properties.
• Nutrient source for yeasts and bacteria in fermentation.
• Used in the preparation of DNA and RNA samples for analysis.

Formulation notes

• For foliar application, sprayed at 100-300 g per 100 liters of water.
• For fertigation of citrus, apply 20-25 kg/ha per week or 150-350 kg/ha total.
• Should not be mixed with fertilizers containing calcium or magnesium.
• Can be used together with potassium nitrate, urea, and suitable water-soluble NPK products.

Typical specification

• NP fertilizer with a declared grade of 12% total nitrogen and 61% water-soluble P2O5 (12-61-0).
• Offered in powder form.
• Technical grade has a P2O5 content of minimum 60.8%.
• Solubility of 58 g/100 ml in water at 25 °C.

Regulatory status

• Marketed as an EC fertilizer (ABONO CE) of the NP type.
• Agricultural, technical, feed, food, and pharmaceutical quality classes should not be used interchangeably.
• Assigned INS number 342(i).
• The MTDI for phosphorus from all sources is 70 mg/kg body weight, expressed as P.

Storage, packaging and handling

• Containers should be stored between 5 and 35 °C in a dry, well-ventilated place.
• Commonly packaged in 25 kg bags.
• Moisture-exposed material can clump, lose flowability, have longer dissolution time, and cause bridging in dosing equipment.

Frequently asked questions about Monoammonium phosphate

What grade forms of monoammonium phosphate are available?

It is manufactured for both food and technical applications.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.