Which of the following chemicals is commonly used in neutralizers?

Sodium bromate is commonly used in neutralizers because it acts effectively to stabilize and reform disulfide bonds in the hair after a perm or relaxer treatment. During the perming process, the hair's natural disulfide bonds are broken down, which allows the hair to be reshaped. After the desired style is achieved, a neutralizer is necessary to restore these bonds and lock the new shape into place.

The role of sodium bromate in this process is crucial, as it aids in the oxidation process that reforms the disulfide bonds, thus providing the lasting effects of the perm and ensuring that the hair maintains its new shape. This makes it an essential component of the neutralization phase in perming treatments.

Other chemicals listed, such as ammonium thioglycolate and glyceryl monothioglycolate, are primarily used as reducing agents during the perming process, specifically to break down the disulfide bonds. Potassium, while a necessary element in some formulations, does not serve the specific function of a neutralizer in perming treatments.