The review was ordered by the Department of Health and will be carried out by two committees on toxicity and mutagenicity.
The spray was introduced in 1996, but has been the subject of increasing public concern and criticism from judges over its inappropriate use. It has replaced the truncheon as the first line of defence for the police even though it was introduced as a weapon for use only in extreme circumstances.
More than 100,000 beat officers have been issued with canisters of CS spray and civil liberties groups and health experts have pointed to dozens of cases in which it has been used when the threat to officers' safety has been negligible or non-existent.
Earlier this week an investigation was launched after reports that police sprayed a 76-year-old man in the face as he was being evicted from his home.
There were also reports this month that several innocent bystanders, including a four-year-old girl, were caught by the spray, which can cause skin blistering and sore eyes.
The chairman of the Police Complaints Authorities recently urged officers not to use it just to make arrests easier and warned of an impending backlash against its use.
The Association of Chief Police Officers said it supported the Government's decision to review the safety of the spray.
John Giffard, Chief Constable of Staffordshire and chairman of Acpo's self-defence arrest and restraint committee, said an independent review was "timely", but added that CS was safer than baton or a firearm. "There has been a certain amount of mis-information on the subject of CS use recently and this will help establish the facts more clearly.
"We believe that the proper use of CS spray poses no long term health risks ... and since 1996 no evidence has emerged to support the propositions that the properly controlled use of CS has long-term health problems. I am convinced that there are people alive today who would have died had CS not been available as an alternative to batons and firearms."
But a spokesman for the Department of Health said: "We're concerned not so much with the use to which the spray is put, but its likely medical and health effects on anyone who receives it."
Alun Michael, the Home Office minister, said the decision to review the spray's safety was a positive move, but insisted it was still an effective self-defence tool for police officers.
"CS spray has been scientifically tested to a level similar to that which would be required for a new pharmaceutical drug, and there is no evidence that it poses any significant threat to human health," he said. "Scrutiny by the committees on toxicity and mutagenicity will provide an independent review of the safety of CS."
It is the solvent used to propel the CS that causes irritation, rather than the CS itself.Reuse content