The S6 NBC Respirator was the protective gas mask

Gas mask

A gas mask is a mask put on over the face to protect the wearer from inhaling airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Some gas masks are also respirators, though the word...

 issued to the British armed forces. It was developed in the 1950s and used from the 1960s up until the introduction of the current-issue S10

S10 NBC Respirator

The S10 NBC Respirator is a military gas mask used within all branches of the British armed forces, and is currently in working service. The S10 is also widely available to the public on the army surplus market.-History:...

 in 1986, after which it was withdrawn from mainstream service, but some still remain in service with RAF personnel.

History

The S6 was developed by the Defence Science and Technology Laboratory, Porton Down from the 1950s and manufactured by the Birmingham & Leyland Rubber Company. Although made obsolete by the introduction of the S10, production of the S6 continued in Turkey after the adoption of the new mask by British forces. During the widely documented Iranian Embassy Siege

Iranian Embassy Siege

The Iranian Embassy siege took place from 30 April to 5 May 1980, after a group of six armed men stormed the Iranian embassy in South Kensington, London. The gunmen took 26 people hostage—mostly embassy staff, but several visitors and a police officer, who had been guarding the embassy, were also...

 of 1980, the S6 is the mask seen being worn by SAS

Special Air Service

Special Air Service or SAS is a corps of the British Army constituted on 31 May 1950. They are part of the United Kingdom Special Forces and have served as a model for the special forces of many other countries all over the world...

troops.

Specifications

The S6 features an innovative air seal around the inside of the face piece to improve the fit and comfort of the mask; the pressure inside the seal can be adjusted by means of a tap inside the nose cup. The mask could also be made to benefit left-handed people, where the filter canister is positioned on the right of the face mask instead of the left.