PAVA spray

PAVA spray is an incapacitant spray dispensed from a hand-held canister in a liquid stream. It contains a 0.3% solution of pelargonic acid vanillylamide (PAVA), a synthetic capsaicinoid, in a solvent of aqueous ethanol. The propellant is nitrogen. This solution has been selected because this is the minimum concentration which will fulfil the purpose of the equipment; namely to minimise a person's capacity for resistance without unnecessarily prolonging their discomfort. PAVA is significantly more potent than CS gas.

The liquid stream is a spray pattern and has a maximum effective range of up to 4 metres. Maximum accuracy, however, will be achieved over a distance of 1.25 – 2 metres. The operating distance is the distance between the canister and the subject's eyes, not the distance between the user and the subject.

Effects of PAVA
PAVA primarily affects the eyes, causing closure and severe pain. The pain to the eyes is reported to be greater than that caused by CS. The effectiveness rate is very high once PAVA gets into the eyes; however, there have been occasions where PAVA and CS have failed to work&mdash;especially when the subject is under the influence of alcohol or drugs. Exposure to fresh moving air will normally result in a significant recovery from the effects of PAVA within 15 – 35 minutes.

Pharmacologically, like other capsaicinoids, PAVA works by direct binding to receptors (TRPV1) that normally produce the pain and sensation of heat, as if exposed to scalding heat.

British police use
PAVA is approved for police use in the United Kingdom. British police forces have traditionally used CS Gas spray. More recently, some forces have opted to use PAVA.

Both PAVA and CS are prohibited under section 5 of the Firearms Act 1968 as a: "weapon of whatever description designed or adapted for the discharge of any noxious liquid, gas or other thing"&mdash;meaning that it is unlawful for a member of the public to possess them. Police officers, as servants of the Crown, are exempt from this restriction.