Scavenger (chemistry)

A scavenger in chemistry is a chemical substance added to a mixture in order to remove or de-activate impurities and unwanted reaction products, for example oxygen, to make sure that they will not cause any unfavorable reactions. Their use is wide-ranged:

• In
  photolytically in the atmosphere. It is the most important oxidant for carbon monoxide, methane and other hydrocarbons, sulfur dioxide, hydrogen sulfide
  , and most of other contaminants, removing them from the atmosphere.
• In molecular laser isotope separation, methane is used as a scavenger gas for fluorine atoms.
• ascorbic acid are used as oxygen scavenger corrosion inhibitors
  .
• free radical scavengers that act as antioxidants; synthetic catalytic scavengers
  are their synthetic counterparts
• Organotin compounds are used in polymer manufacture as hydrochloric acid
  scavengers.
• Oxygen scavengers or
  self adhesive labels that are placed inside modified atmosphere packs to help extend product life (notably cooked meats) and help improve product appearance. They work by absorbing any oxygen left in the pack by oxidation of the iron powder contained in the sachet/label.^[1]
• alkylating electrophiles, which may be exogenous toxins or produced in the course of metabolism (e.g. NAPQI from paracetamol
  ).