Q505: What is CS spray made up of and when do the police use it?
CS (named after the initials of the inventors Corson and Staughton) combines the compound (o-chlorobenzylidine malononitrile) a white crystalline substance which is dissolved in the inert solvent MiBK (methyl iso-butyl ketone) and held by this substance in suspension. When it is expelled from the canister as a liquid jet, the CS compound which is suspended in the liquid compound (MiBK) separates from the matrix liquid on contact with the air.
Any cannister of whatever description, designed or adapted for discharge of CS spray is a prohibited weapon.
Police officers are regularly trained in the use of CS spray and an officer who is faced with violence, or the threat of violence, may decide to use it in the circumstances.