What chemicals are in toothpaste that whiten teeth?

Whitening TP's: Abrasives to remove surface stain and some form of hydrogen peroxide to bleach the enamel. They are only minimally effective and there is some danger in using these toothpastes on a regular basis.

Whitening toothpaste: All whitening toothpastes rely on being more abrasive to remove superficial stains from coffee, tea, cigarette smoke etc. They do not contain any whitening ingredients.While they may help initially, continued use can make the teeth darker as the outer lighter color is worn away revealing the darker inner structure. Also may make them more sensitive.