Gas Mask and Respirator Wiki
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The S10 respirator was the mainstay respirator of the British forces between 1987 and 2012 which represented a major step forward in respirator development in protection compared to the previous S6 (offering 12 hours of continued protection) but also serviceability and modularity. The S10 saw reasonably wide adoption from Britain to Australia along with Malta and New Zealand and proved popular with law enforcement until the development of the FM12.


As the S6 respirator was nearing the 20-year mark of service the evolving CBRN threats presented in the late cold war prompted Porton Down to begin research and development on a new service respirator. These experiments and tests culminated in the R# series of respirators (including the R8 often wrongly called the S8) these experiments revolved around better performance with optical equipment and furthering resistance to threats.

With the exception of the R8 none of these designs made it into production, and even with the R8 its issuing was extremely limited at best and by the early 1980s, the S6s age was becoming more and more apparent leading to the NGASR 3848 document being issued[1] setting out a list of requirement and expectations that the respective branches desired from a new respirator. Leading on from this several prototypes were developed in the early 1980s by Porton Down and possibly Avon Rubber along with Layland Birming Rubber with field trials having seemingly started in 1982 with the last known prototype dating from 1984. Information from these documents will be added once it can be researched.

Coming off a successful trial the S10 respirator entered production in 1986 with Avon Rubber plc as the only contractor for the mask (marking the first time a service respirator of Britain has only had a single manufacturer) this is despite a Soviet document alluding that LBR possibly had involvement in the development cycle however this is currently unconfirmed. After mass production had started issue began sometime in 1987 with its first major trial being in the gulf war where several issues in relation to hot environments arose: namely the harnesses slipping, poor ventilation and valves sticking. This was due to the design of the S10 being centred around a hypothetical war in Europe between NATO and the Warsaw pact, however many of the issues presented were resolved in the coming years with minor amendments to the design but the issue with heat continued to plague the S10 up until it was phased out.

Mid-life redesign

The mid-life redesign took place just after the Gulf war to correct and improve certain parts and features of the S10 respirator, which are; harness buckle tabs, orinasal cup, valve rubber specification and lower harness buckle attachment point on the mask itself.


The S10's basic layout consists of 2 round lenses, a forwards facing exhale valve with integrated Primary Speech Module and 2 ports on each lower side of the respirator which on regular S10's house the Secondary Speech Transmitter (And clansman radio system port) on one side with the filter port on the other.


Diagram from Survive to Fight detailing components of the S10

Eyepieces on the S10 consist of a rather brittle plastic and come in 2 different types. The more common indented Lens which is known as a "plano lens" (respirator designation L2A1) allows for use with optics and provides minimal disruption to the field of view. However, it prevents any use of the optical correction inserts which require a separate lens type which is referred to as "corrective lens" (respirator designation L3A1). These specialized corrective lenses have several disadvantages when compared to the L2A1 lenses, namely the FOV is significantly reduced and (similar to the S6) it causes a "fisheye" effect when looking out the outer side.

S10 Lenses are held on with plastic rings that have rubber gaskets, these outer rings/ridges also provide outsert capability. The rings themselves can be removed via the help of the S10 repair kit to allow for replacement of broken/damaged lenses however to do this without the correct tools is both difficult and could end up damaging/breaking the lens assembly.

Speech Capability

Speech clarity in the S10 stems from 2 places, the Primary Speech Module or as Avon calls it the "speech cone" and the Secondary Speech Transmitter, better known for being the radio port. The Primary Speech Module works via reverberating the noise coming from the exhale valve port and the space around it to make the user more easily understood, this eliminates the need for a forward-facing speech diaphragm. A similar design (which is patented by Avon) can be found on Avons M50 and its variants. The PSM cover also doubles as the cover for the exhale valve.

The Secondary Speech Transmitter is an actual speech diaphragm that allows for use of field telephones and radio equipment much more easily than more traditional forward-facing designs it also allows for integrated use of the Clansman radio system with a specialised attachment that clips on. This design is also found on single port FM12's.

Drinking Device

First introduced on the S10, the drinking system is the regular Avon style but lacks any sort of drinking system "holder" or clip in the canteen cap as is found on the FM12, M/C50 etc. Working via a leaver connects to a spindle that has the drinking tube and shutoff valve on it. To activate the drinking system the leaver is turned from the "up" position anti-clockwise until it is fully in the "down" position, doing so will also rotate the drinking tube to the user's mouth.

The S10 was issued with the L9A1 drinking cap for 58 pattern water bottles, which allows for the "Drinking Coupler Male (DCM)" to be inserted and used.

A design flaw that can be found on all S10's is spindles have a tendency to crack, this can cause a leaky drinking system and a propensity for inner drinking tubes to fall out or not turn correctly.


The Differences between pre and post midlife redesign roundels.

Consisting of a rigid butyl rubber mask the respirator can withstand blister agents and all known chemical and nerve agent-based weapons at the time of its introduction for a length of up to 4 hours. The mask itself has a ridge running around the edge for use with Mk IV NBC suits. Masks can be dated by the date roundel on the side of the mask itself, pre and post midlife redesign masks can be distinguished via if the roundel only "AVON" or "Avon UK" with the latter indicating a post midlife redesign mask. Coming in 4 sizes the mask's size can be found on the right hand side.

S10 Mask sizes.
Size No. Worded Correlation.
1 Extra Large
2 Large
3 Medium
4 Small

Headharness & Adjustment System

The headharness is a rubber 6 pointed style which attaches by use of plastic "buckle tabs" that have 2 different styles depending on the respirators era (pre or post midlife redesign), these buckle tabs are designed to clamp down tightly upon the straps holding them in place.

The Headharness itself is designed for quick donning with the 2 lower straps being thinner and more stretchy allowing for the headharness to be pulled over the head.


Picture of interior showing airflow.

The S10's interior consists of the Airguide (oronasal cup), inner drinking tube, exhale valve assembly and the inner side of the lenses.

Pre and post midlife redesign airguide.

The Airguide comes in 2 different styles depending on if they're pre or post midlife redesign, the earlier type having circular air inlets on each top-side while the later type has more of a slit. The airguide and installed via being slotted into a ridge located on the valve assembly and a "button" located near the chin area. Another difference with pre and post midlife redesign is that the airguide is secure to the "button" with an "air guide clip", this was to prevent fogging of the lenses more reliably when combined with the cutout at the top of the airguide. The airguide also has the main chin rest, a design choice continued on to the Scott GSR. Airguides come in 4 sizes, these are not officially supposed to be interchangeable with respirators that are not the corresponding size but there are accounts of soldiers doing so.

When not in use the inner drinking tube sits off to the right side, rotating downwards toward the user's mouth when the lever is turned.

The exhale valve assembly, which doubles as a speech module houses the exhale valve and the ridge for the airguide to be secured.

The interior side of the lenses holds the "clips" for the optical correction inserts to be attached to.

Accessories & Attachments

Optical Correction Inserts

Called optical correction monocles by Avon these inserts provide a user who requires glasses the ability to see correctly while wearing a respirator. To use these a different respirator lens is needed, with the entire respirator having its own designation, the L3A1 as opposed to the L2A1 with the regular lenses, this is due to the outer edge of L2A1 lenses being too high and causing the inserts to warp. The inserts were installed by a trained CBRN technician via taking the inner outcrop of the insert and pulling it through a raised hole on the inside of the lens rims, the same is then done for the outer arm of the insert into the corresponding raised hole with the excess that sticks out of the attachment point being tucked behind the seal.

The inserts caused some significant issues with the respirator, however, including some stemming from the specialised lens type needed to use them. One such issue was fullers earth decontamination power had a habit of falling behind the inserts and getting stuck, hindering vision and possibly causing respiratory problems when a user dons the mask. Another issue that occurred especially in hot climates was the sun being magnified by the lenses and causing the lens to degrade, the side effect of which can still be seen today with many L3A1 respirators having significant lens damage from layer separation and deterioration. The lenses themselves produced a "fish eye" effect not too dissimilar to the one seen in the S6 when a user looks either left or right causing possible nausea.


Outserts for the S10 consist of a rubber "holder" where the outsert lens is placed into which clips onto a small ridge that runs around the outside of the lens rims, the outset lenses themselves are very slightly domed as to allow use with either L2A1 or L3A1 lens types. The outserts come in a variety of different types which are for different uses against threats, these include laser blocking outserts and the famous "anti flash" outserts as used by the SAS with the SF10. Clear outserts surprisingly do not exist.


The S10 VPU is similar in appearance to American VPU's of the same era, it is unknown if they are derived from American VPU's. VPU's required a specialised PSM cover with a notch at the top to allow for the VPU to be attached. The VPU was only ever used the SAS and in very limited numbers, British police making both the VPU and specialised PSM cover very rare.

Radio Equipment

Expanding upon the clansman radio "bracket" for use with the S6, S10's have an integrated port within the SST that allows for the microphone to be easily attached and detached. The microphone itself uses a regular clansman style microphone component mounted into a rubber-coated "housing" which has a wire running from it to be attached to the clansman radio headset, the microphone provides reasonably clear audio and is a definite improvement over a boom mic.

Nomex/Fire Retardant hoods

Hoods made to fit the S10 family were often issued to the SAS with the SF10, hoods were often also used by Armed Police using the S10 and regular soldiers performing specialist duties.

Repair Kit



Over the S10's service life there have been 3 main kits using 3 different haversacks utilised by the RAF and Army, each are listed in tables below with an additional kit that would've sometimes been used to use up old stocks. The navy used a significantly different kit to the other branches. W = only issued in wartime. The navy used significantly different kits, which lacked a sealed canister, detector paper & NAPS, BATS plus combo pens. One extra thing that naval kits had however was that all kits were named with a name tag (same type that was used with the MkIV GSR onwards).

Early (1986-1991)
Full Contents of Kit
Pre midlife redesign S10 respirator facepiece (L2A1 or L3A1)
Mk.2 or Mk.2A haversack
L10A1 or Mk.2 No.1 filter(s)
Respirator Card
No.2 Mk.2 detector paper
No.1 Mk.1 DKP1
No.2 Mk.1 DKP2
L1A1 facelet
Cloth disinfecting (cleaning cloth)
Atropine Combo Pens (L2A1) W
NAPS (Nerve Agent Pre-Treatment Tablet Set) tablets W
Mid-Early (1990-1995?)
Full Contents of Kit
Pre midlife redesign S10 respirator facepiece (L2A1 or L3A1)
1990 Pattern PLCE haversack
L10A1 or L12A1 (PS10) filter(s)
Respirator Card
No.2 Mk.2 detector paper
No.1 Mk.1 DKP1
No.2 Mk.1 DKP2
L1A1 facelet
Cloth disinfecting (cleaning cloth)
Atropine Combo Pens (L4A1) W
NAPS (Nerve Agent Pre-Treatment Tablet Set) tablets W
Mid-Late (1993-2002)
Full Contents of Kit
Pre & Post midlife redesign S10 respirator facepiece (L2A1 or L3A1)
DPM IRR PLCE haversack
L12A1 (PS10) filter(s)
Respirator Card
No.2 Mk.2 detector paper
No.1 Mk.1 DKP1
No.2 Mk.1 DKP2
Oro-Nasal mask (3m dust mask) or L1A1 facelet
Cloth disinfecting (cleaning cloth)
Atropine Combo Pens (L4A1) W
NAPS (Nerve Agent Pre-Treatment Tablet Set) tablets W
BATS (Biological Agent Treatment Sets) W

Late (2002-2014)
Full Contents of Kit
Post midlife redesign S10 respirator facepiece (L2A1 or L3A1)
DPM IRR PLCE haversack
L12A1 (PS10) filter(s)
Respirator Card
No.2 Mk.2 detector paper
No.1 Mk.1 DKP1
No.2 Mk.1 DKP2
Oro-Nasal mask (3m dust mask)
Cloth disinfecting (cleaning cloth)
Atropine Combo Pens (L4A1) W
NAPS (Nerve Agent Pre-Treatment Tablet Set) tablets W
BATS (Biological Agent Treatment Sets) W


Do not add a "doffing procedure" as it did not exist with the S10.

Dress States. As per Survive to Fight.
State Respirator Meaning
0 Respirator/Mask Carried Respirator/1st set of IPE within Unit.
1 Respirator/Mask Carried IPE carried or immediately available.
2 Respirator/Mask Carried Suit worn, boots & Gloves carried.
3 Respirator/Mask Carried Suit & Boots worn, Gloves carried.
4 Respirator/Mask Carried Suit,Boots & Gloves worn.
Donning Procedure. As per Survive to Fight.
1. Stop breathing, close eyes, turn back to wind, lean forward, shield hands. Remove helmet (and spectacles) place helmet between knees, top uppermost.
2 Pull back [NBC suit] hood
3. Grasp the respirator by the PSM and remove from haversack.
4. Put thumbs under bottom 4 harness straps and keep apart. Thrust chin into facepiece.
5. Pull harness over head allowing plenty of space, release gently. Check head pad is central and no straps are twisted.
6. Blow out hard.
7. Shout GAS, GAS, GAS.
8. Continue normal breathing, Open eyes.
9. Pull up hood.
10. Check elasticated edge of hood locates over rib [rim] of respirator. Check seal of suit under chin.
11. Repalce helmet, (pick up glasses).
12. Do up haversack.

Another somewhat unknown drill was that for ordnance disposal while using the S10. Found in the repair kit manual (1986 & 1991 editions) it calls for the Male Drinking Device to be removed from the respirator (The MDD is the only component in the S10 to have any metal in it, there's a small spring to close the valve when not in use.) and for the drinking tube to be tied two times, haversacks and anything which had metal mustn't be carried as to prevent a magnetic mine or some other similar explosive device from been detonated.

Current uses

The S10 is currently being used by the Australian Defence Force (ADF) as the ADF-10 as of March 2021, but is currently being phased out in favour of the Airboss LBM.

The S10 and SF10 are in use by Hong Kong riot police and the Special Duties Unit (SDU) but is slowly being replaced by a plethora of masks.


Finishing in 2014 the UK issued S10 was fully replaced by the Scott GSR with a handful of respirators retained for training and testing purposes.

Starting in 2019 the ADF10 is slowly being replaced by the Airboss LBM.

New Zealand issue S10s have been fully replaced by the Scott GSR as of March 2021.

Commercially the S10s successor was the FM12, which is based upon the basic design principles of the S10.

Malaysia has replaced all S10 in service with C4, FM12, and Avon C50. All S10 are in the process of disposal.


The basic S10 mask and layout proved popular around the world with different services and nations, this lead to various different types, copies and variations to be created to suit different needs.


The AR10 designation refers to a wide range of respirators issued to non-combatant personal, these come in various setups and layouts ranging from some being a regular S10 to others being closer to the SF10, with many respirators in-between.



N10 with white PSM cover. Credit to GasmasksUK

Developed in the early 1990s by Avon for industrial usage the N10 was first exclusively sold to British Nuclear Fuels Ltd under government contract to replace their aging stocks of converted Light A.G. respirators and converted C7's, later being sold to other companies commercially by Avon. Early government contract N10s and later commercial N10s can be told apart via the early contract respirators having a smooth blanking plate with no Branding, name or cert info. N10s are best known for their use at Sellafield nuclear reprocessing plant where they remained in service until around 2016.

Differences from S10

One of the main most noticeable differences is that all plastic furniture save for the valve assembly and drinking port blanking plug are in a light grey colourway which includes a blanking plate in place of the Secondary Speech Transmitter, another significant difference is the strap system which uses a more industrial type ripped fastener system, which allows for the respirator to be secured more reliably to the users face. Another minor little known variation from the S10 is the filter port o-ring is significantly thinner than the one which comes standard with most S10 family respirators, this is assumed to be for allowing a filter to sit closer to the respirator saving on space.

Rare N10 with drinking tube. Credit to

As is usual for all S10 variants without a drinking tube the valve assembly hasn't been milled out to accommodate the drinking system.

A Primary Speech Module cover unique to the N10 was issued to supervisors at Sellafield and possibly other places where it was used, this PSM cover was white instead of the usual grey.

Another extremely rare variant which bares the N10 designation is an N10 which seemingly has a drinking tube from factory, nothing is known about these and its highly likely it'd fall into the AR10 category in terms of usage (civilian agencies, police etc).


The N10 is known to have been used commonly with the Scott Pro2000 P3 filter at Sellafield, it was also seemingly used with normal and blue L12A1 (PS10) filters.


Used by the SAS, SBS and a handful of other special operations units within the British armed forces the SF10 is a modified version of the S10 platform. Used from approx 1988 (not 100% known) to around the early to mid-2000s when it was replaced by the CT12 the SF10 was designed to be a light tactical breach respirator that could withstand impacts, these requirements can be seen in the lack of a drinking tube and flat polycarbonate lenses. Another difference between the SF10 and regular S10 is that the valve assembly isn't milled out for a drinking tube, this is the same on all S10 variants that lack drinking tubes. SF10s were commonly used with Nomex hoods.

Many "SF10s" aren't in fact genuine SF10's, Police AR10s existed in the exact same setup, to prevent getting scammed try to make sure that the SF10 you are buying has the following; Anti flash outserts, specialised filter. furthermore having a nomex hood and a genuine SAS beltloop bag is further guarantee that it is a genuine article.


An extremely rare derivative of the SF10 which has an internal microphone mounted in place of the drinking tube.


In the early 1980's, the United States had begun the XM40 Trials to once again find a replacement for the aging M17 Series Field Protective Masks that had been in use since 1959. Many companies submitted designs for a new protective mask, including Avon Rubber, who in 1983, submitted a version of their S10 Respirator which had been modified to fit U.S. Army requirements.

This modifications consisted of:

  • Non-'Plano'-Type Lenses
  • M1 Quick-Disconnect Drinking Tube Adapter instead of the Avon DCM
  • Dual-port compatibility, unused port blanked with standard MCU-2/P Side Voicemitter
  • C8R1 Elastic Head Harness

The kit itself was also changed from the standard S10, comprising of:

  • Low-profile snap-on Plastic Outserts
  • C2 Canister
  • Butyl Protective Hood (Optional)
  • Carrier, MCU-2/P Series Mask

In addition to this, the US10 also adhered to the XM40 Trials Requirements by introducing several variations for specific roles:

  • US10 - Infantry
  • US11 - Aircrew
  • US12 - Combat Vehicle Crew
  • US10 SPM - Special Purpose/Decon

The US10, with its chlorobutyl rubber and polymer hardware was unconventional when compared to its adversary competitors from American companies, all of whom stuck to using olive drab silicone and metallic hardware for their concepts. In trials, the US10 Performed exceptionally when compared alongside ILC Dover and Scott Prototypes, however despite exceedingly good marks in protection, reliability, and end-user trust, the US10 and the ILC XM40 lost to the poorest-performing Scott XM40, likely due to the latter being the lowest bidder for the contract [citation needed].

On the private market, less then 6 US10 Specimen are known to exist, with a majority residing in private archives at Fort Leonard Wood and Avon Rubber Headquarters.

Foreign Copies And Export Models

Due to the S10's successful reputation, at least two countries currently developed their own copies of the S10. These include Pakistan and China, however, some models have been exported to other countries.


A rather rare export model of the S10, redistributed by KX Defense[2][3], an American company. Its key difference is that the mask was pre-packaged with a six-point elastic head harness, seen on most US military masks, unlike the standard rubber one used on the original. While it was designed for law enforcement agencies within the US, it still retained the drinking tube, overall it's just the standard S10. Meaning it is compatible with most, if not all of its accessories.[4]


A licensed and direct clone of the Avon S10, in service with the Pakistani Armed Forces. The PAK-10 is noticeably cheaper in build quality and materials used, with this being most evident in its weight of 0.3KG compared to the S10's 0.6KG. The rubber (which might be synthetic) is slightly sticky and is jet black in colour in contrast to the S-10s dark grey. Another difference can be found in oral-nasal cup and how it is shaped and attached, with it clearing being a different design. It isn't known which factories produce the PAK-10 however at least one of the factories has the stamp of "SIL" (can be seen in the photos section). This factory from what can be gathered by translation of Urdu web pages is somewhere in Islamabad.


A licensed and direct clone of the SF-10, possibly issued to Pakistani special forces.


Main article : MF-20

A Chinese clone with close resemblance to N10 but with a secondary voice emitter like on the S10.


Main article: MF-22

A Chinese clone of the S10, similar only in appearance. The MF-22 features a different voice diaphragm and exhale valve assembly, as well as a different, exhale valve cover. Currently in service with the Chinese PLA. There is a dual-inlet version designated as MF-22A.


Used by the Australian Defence Force.



Information on variations on S-10 Mask has been sourced from here