The S10 CBRN Respirator is a military gas mask that was formerly used within all branches of the British Armed Forces. Following the mask's replacement by the General Service Respirator in 2011, the S10 is now widely available to the public on the army surplus market.

The S10 was introduced in 1986 as a replacement for the S6 NBC Respirator^[1] in service from the 1960s, and is manufactured by Avon Rubber.^[2] S10s were issued to British nationals in Saudi Arabia during the 1991 Gulf War and were marked by a blue coloured PSM (Primary Speech Module) fitting or a blue painted spot on the forehead.

The S10 respirator was originally due to be replaced by the new General Service Respirator (GSR) in 2007, although replacement efforts officially began in 2011 and all S10 Respirators have since been replaced with the GSR. All issued filters for the S10 have expired, the last of which expired in 2014. No new S10 Respirators will be bought.^[3]

The mask includes a fail-safe drinking device, a Secondary Speech Transmitter (SST) on the side^[4] which a Clansman radio system microphone can be clipped to, and corrective lenses can be fitted to the eyepieces. The mask also contains an inner oro-nasal mask to decrease fogging on the lenses. This mask is fitted with optical insert hooks, and therefore can be used by soldiers who wear glasses.

Variants include:^[1]

• SF10, intended for security and special forces use (replaced, at least in SAS service, by the CT12 version of the FM12)
• AR10 for police forces
• N10, a commercial version.