peroxide is produced from sodium metal and oxygen (from air) in two steps:

Sodium monoxide is first produced by adding sodium metal intermittently to sodium monoxide in a rotary tube reactor while passing air through it countercurrently. The sodium metal rapidly distributes itself over the surface of the monoxide and in doing so is oxidized. The reaction temperature is 200 to 700 °C and the heat of reaction is sufficient to maintain this temperature. In this way a noncaking material is obtained. The monoxide formed, containing a few per cent of peroxide and less than 1 % sodium is withdrawn from the reactor intermittently.

The oxidation of the monoxide to sodium peroxide is carried out in a similar reactor at 350 °C. As this step is only slightly exothermic (-79.5 kJ/mol) heating is needed. The end product is formed as beads with a diameter of 0.5 to 1 mm and a purity of 97 to 98 %.