A peroxide forming chemical is one that contains a peroxo (O-O) unit, one that has the chemical formula of O2² ... a peroxide formation inhibitor (e.g., tetrahydrofuran or diethyl ether inhibited with ...

Technically, ether is not a chemical; it is a class of organic chemicals that contains a Carbon-Oxygen-Carbon (C-O-C) fragment. But the term "ether" is also a universal abbreviation for diethyl ether.