- ▸ Intumescent coatings: Acid source in intumescent fire-protective coatings.
- ▸ Flame-retardant plastics: Halogen-free flame retardant for polymers.
- ▸ Liquid fertilizer: Phosphorus and nitrogen source for crops.
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →Ammonium polyphosphate (CAS 68333-79-9) is an inorganic polymeric phosphate salt. It is used as a halogen-free flame retardant in intumescent coatings and polymers and as a phosphorus-nitrogen source in liquid fertilizers.
Frequently Asked Questions
What is ammonium polyphosphate used for?
Ammonium polyphosphate (APP) is an inorganic polymeric phosphate salt used as a halogen-free flame retardant; it acts as the acid source in intumescent fire-protective coatings, as a flame retardant in polymers and plastics, and as a phosphorus-nitrogen source in liquid fertilizers. CAS 68333-79-9. It is supplied in industrial grades for coatings, polymer, and agricultural use.
How does ammonium polyphosphate work as a flame retardant?
In intumescent systems APP decomposes on heating to release phosphoric acid species that catalyze char formation, and the resulting expanded char layer insulates the substrate from heat and oxygen. This makes it a halogen-free acid source in intumescent coatings and a flame retardant in polymers. Performance depends on the chain length and grade selected.
What is the difference between ammonium polyphosphate grades (Phase I vs Phase II)?
APP is offered in different crystalline phases and chain lengths; lower-chain Phase I grades are more water-soluble and suited to liquid fertilizer, while long-chain Phase II grades are less soluble and preferred for coatings and polymer flame retardancy. All share CAS 68333-79-9. Select the grade and solubility profile to match your application and request the matching CoA.
Is ammonium polyphosphate water soluble?
Solubility depends on the grade: short-chain APP is appreciably water-soluble and used in liquid fertilizers, whereas long-chain APP is only sparingly soluble, which is desirable in coatings to resist leaching. Confirm the solubility class on the product specification. The SDS covers handling.
How is bulk ammonium polyphosphate packaged and priced?
APP is supplied as a powder or liquid in bags, supersacks, drums, totes, and bulk to manufacturers. Pricing depends on grade, chain length, form, and volume, so request a bulk quote rather than a list price. The SDS and CoA are provided with the quote.