Chlorine gas , Chlorine dioxide , Nitrogen dioxide , Calcium, benzoyl peroxides and Azodicarbonamide are the ingredients that were used to bleach flour in the US for a short time.
Step-by-step explanation:
Harvey W. Wiley, head of the FDA struggled against benzoic acid, saccharin, sulfites and bleached flour. He prevented the bleaching of flour and got the practice of bleaching flour banned in the US for a short time.
Flour bleaching is a chemical treatment that are added directly to the freshly-milled flour to produce whiter and finer-grain flour.
These bleaching agents are poisonous, powerful irritant and dangerous to inhale. Alloxan causes diabetes and creates greater risk to the public.