Calcium pyrophosphate (Ca2O7P2) is a chemical compound that can be formed by the reaction of pyrophosphoric acid and a calcium base or by strongly heating calcium hydrogen orthophosphate or calcium ammonium orthophosphate.

Farnesyl pyrophosphate (FPP) is an intermediate in the HMG-CoA reductase pathway used by organisms in the biosynthesis of terpenes and terpenoids.

Pyrophosphates were originally prepared by heating phosphates: the prefix pyro- derived from Greek, means "fire" in this context. Pyrophosphates are good complexing agents and have many uses in industrial chemistry. Pyrophosphate is the first member of an entire series of polyphosphates.

Isopentenyl pyrophosphate (IPP) is an intermediate in the classical, HMG-CoA reductase pathway used by organisms in the biosynthesis of terpenes and terpenoids. IPP is formed from acetyl-CoA via mevalonic acid.

Tetrasodium pyrophosphate, also called sodium pyrophosphate or tetrasodium phosphate, is a slightly toxic and mildly irritating colorless transparent crystalline chemical compound with the formula Na4P2O7. It contains the pyrophosphate ion.

A salt or an ester of pyrophosphoric acid.

It has chemical formula K4P2O7.

Tetrasodium pyrophosphate, also called sodium pyrophosphate or tetrasodium phosphate, is a slightly toxic and mildly irritating colorless transparent crystalline chemical compound with the formula Na4P2O7. It contains the pyrophosphate ion. Toxicity is approximately twice that of table salt when ingested orally.[1]. There is also a hydrated form, Na4P2O7.10(H2O)