Polyphosphoric acids
[CAS 8017-16-1]

Identification

• Classification: Inorganic chemical industry >> Inorganic acid
• Name: Polyphosphoric acids
• Molecular Formula: (H)_n+2.(P)_n.(O)_3n+1
• CAS Registry Number: 8017-16-1
• EC Number: 232-417-0
• SMILES: [P](=O)(OC)(O)O

Properties

• Density: 2.06 g/mL
• Boiling point: 300 °C
• Water solubility: MAY DECOMPOSE

Safety Data

• Hazard Symbols: GHS05 Danger
• Risk Statements: H290-H314
• Safety Statements: P234-P280-P303+P361+P353-P304+P340+P310-P305+P351+P338-P363

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Serious eye damage	Eye Dam.	1	H318
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	3	H301
Skin corrosion	Skin Corr.	1C	H314
Skin corrosion	Skin Corr.	1	H314
Specific target organ toxicity - single exposure	STOT SE	3	H335

chemBlink Chemical Story

Polyphosphoric acids matters because polyphosphoric acid is a controlled mixture of condensed phosphoric acids joined by P-O-P bonds, whose combined acidity and dehydrating power make the mixture itself the useful reagent. This connection between molecular structure and observable behavior is more informative than a simple list of uses. CAS 8017-16-1 identifies the substance in this chemBlink record, while its practical significance comes from the way its functional groups, composition, or material structure control reactivity and physical properties.

The broader lesson is that chemical identity alone does not determine performance. Conditions such as pH, temperature, formulation, concentration, molecular distribution, or biological environment can decide whether the same underlying chemistry is useful, inactive, or hazardous. For chemists, Polyphosphoric acids is therefore a useful case study in connecting molecular-scale behavior with a real laboratory, industrial, biological, or materials-science outcome.

References: ECHA/PubChem identity records, CAS 8017-16-1; organic synthesis literature

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