In a cold permanent wave, which chemical acts as the reducing agent that breaks disulfide bonds?
a.Sodium hydroxide
b.Hydrogen peroxide
c.Sodium bromate
d.Ammonium thioglycolate
Explanation
Cold waves use ammonium thioglycolate (ATG) as the waving lotion. It is a reducing agent that breaks disulfide bonds at room temperature. The neutralizer (usually hydrogen peroxide or sodium bromate) then re-forms the bonds in the new shape.
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