Gas Mask and Respirator Wiki
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The General Civilian Respirator first came into being from a patent filed by John A. Sadd on the 10th of January 1935, with the overall stated goal of an improved respirator which, by means of simplicity, could be easily mass produced and thus suited to civilian usage. In subsequent years, the General Civilian Respirator was issued to every civilian by the government in the late 1930s and early 1940s. Civilians were legally required to have their gas masks within reach at all times, and there was an extensive propaganda campaign designed to increase awareness.


The masks sheet rubber was thin and fairly poor quality - many ARP manuals note that the same chemicals used to clean the Civilian Duty cannot be used to clean the GCR. An Izal solution (one or two eggcupsful of Izal/Izol to 3 gallons of water) was used to clean CD respirators, whereas manuals recommended a disinfectant comprising 2% Formalin (an aqueous solution of formaldehyde) for GCR cleaning. Many rubber producers were contracted for the facepiece including Avon, Henleys Tyre and Rubber co. and Leyland Birmingham Rubber.  

Vision was provided by a thin non-flammable celluloid sheet that was stitched into place. This was a structural weakness of the respirators' design. It was later feared that small amounts of deployed gas could seep through the stitch holes on the front. This flaw was rectified in 1940, the solution being to apply latex around the stitched areas to create a gas-proof seal. 

The straps of this mask were very basic and simply went over the head (3-pointed harness). The length of the straps could be changed by removing the safety pins and replacing them when the desired length was reached.

In early 1940, an immediate inspection of all civilian masks was proposed. This inspection was to be carried out by wardens. Under the Civil Defence Act, citizens could be fined £5 for repairs or replacement of a respirator if such damage was caused by negligence.


GC filter

The GCR filter (GC Mk II and later, GC Mk III) was attached to the mask via a rubber band that could be removed prior to disinfection. Like most filters, it contained an activated charcoal layer and a particulate layer consisting of asbestos-wool, and later, resin-wool.

Interestingly, very early models (1935) of this mask do not have asbestos in their particulate layers. Instead, the particulate layer consisted of Merino wool impregnated with Carbon Black. This was soon swapped for Merino wool impregnated with asbestos. 

After May 1940, an additional filter known as the Contex Extension filter was introduced to supplement existing filters due to fear of arsenical smokes. Local wardens were given the overall task of fitting these new Contex filters to every civilians mask.  

Some of the GC filters are marked with coloured bands around the filter container. A green band signifies that resin-wool was used. A white band is sometimes seen on GC filters as well. According to 'Care and Repair of Respirators' (1939 Ed.) the white band signifies a filter whose charcoal has been supplied after a certain date.

The filters used on the GCR can be categorized by either their GC marking or their 'MB' markings. As per Porton Down (1989), the GCR can be equipped with the following GC filters: 

GC Mk II (additionally, Mk II A or Mk II B)

GC Mk III (additionally, Mk III A or Mk III B)

The significance of the 'A' and 'B' designations is unknown, with researchers at Porton Down concluding that 'A' and 'B' may be in reference to the source of the charcoal or possibly denoting a different chemical impregnation of said charcoal. 

GC filters generally have a stamped 'MB XX' mark on them, where 'xx' is the year of manufacture, e.g. MB 37 = filter was produced in 1937. During the aforementioned 1989 study, the following conclusions were reached:

All filters with MB 36, MB 37, MB 38, MB 39 and MB 40 contain asbestos.

All GC filters equipped with the Contex Extension filter will contain asbestos, but the Contex itself does not.

Filters marked with MB 41 need caution as they may or may not contain asbestos as this was during the asbestos-wool resin-wool transition period.

Filters marked with MB 42, MB 43, MB 44 and MB 45 are highly unlikely to contain asbestos.

Mk II and Mk III filters were filled with both asbestos-wool and resin-wool, thus the Mk number is not useful in determining asbestos presence. 

Fitting and care of respirator[]

The GCR was produced in 3 sizes (Small, Medium and Large) with one of the headstraps being marked as such. During initial fitting, it was recommended that men first try a 'Large', women and adolescents 'medium' and children 'small'. The GCR was not equipped with apparatus for spectacle usage, thus if spectacles were worn, had to be removed prior to wearing.

To put on the respirator

Hold the respirator by each of the side straps with the thumbs underneath the straps, so that the inside of the window is facing you. The respirator will thus hang from the straps in the proper position for putting it on the face. Lift the respirator to the face, thrust the chin forwards into it and draw the straps over the top of the head as far as the will go.

Release the straps and make any small adjustments that may be necessary, e.g., the edge of the rubber may be turned inwards under the chin, one of the straps may be twisted or the facepiece may not be straight.

Strap Adjustment

When the respirator has been put on, make sure that the buckle is at the back of the head just below the crown so that the two side straps are roughly level. Then adjust the straps, keeping the buckle in the same correct position so that the facepiece is in contact with the skin all round the face.


Eye position

Action required

Wearers' eyes are roughly in middle of window, eyebrows visible below top of window Respirator is considered to fit well, no action necessary.
Wearers' eyes are much above the window, eyebrows cannot be seen Ensure respirator is properly fitted, ensure no twisting or rubber caught anywhere. If fitting problem persist, a larger size is advisable. If wearer is already wearing size 'LARGE' it means the wearers face is of unusual length, but ARP manual (1941 Canadian reprint) claims respirator will still offer full protection.
Wearers' eyes are much below the window Smaller size respirator recommended.

Care and Inspection of Respirator

This table has been produced using information from ARP manuals. Check references section for more details.

Respirator part

Care & Inspection

Facepiece Keep in container when not in use.

Do not expose to high temperatures e.g. near radiator.

Always remove respirator by drawing the head harness, never remove respirator by pulling the filter upwards.

Do not expose to strong sunlight.

Facepiece can be sponged gently with water (not hot) and soap, taking care to ensure excess water is drained from sponge before application.

Facepiece must be periodically checked for cracking, perishing or holes in the rubber. Suppleness can be checked by taking the edging and, with finger and thumb about 1 inch apart, stretching the rubber to about 2 inches.

If wet from rain, dry with cloth.

Ensure all stitched areas on the mask are in good condition.

Ensure stockinette that covers the seam on the facepiece is adhered firmly.


When cleaning the GCR window from the inside, ensure hand supports the window from the outside.

Periodically check for splits, creases or holes.

If window is creased, it must be checked carefully for holes.

Inlet valve Periodically check for perishing or other damage.
Straps Do not hang by straps, always store in box.

Check for other damage.

Safety pins Ensure they are present and usable.
Filter Canister Check for dents or other damage

Ensure water does not come in contact with filter contents.

Rubber band Check for perishing, cracks, splits or other damage.

Repair of General Civilian Respirator[]

Unlike the Civilian Duty and the GS respirators, no special tools are required for repairs.

Parts (Stores Nomenclature) Required for Repair procedure
Tape, adhesive 1'' Affixing Contex Extension Filter Place Contex with its smooth recessed face and rim uppermost on a table.

Place the respirator filter over the Contex, so the rims of the filter and the Contex meet.

Measure and cut 24'' of adhesive tape.

Hold the respirator filter and Contex together and place one end of the tape on both protruding rims. The tape should be placed so it lies equally on both the Contex and respirator filter.

Rotate the respirator so the tape is wound symmetrically around the new filter assembly.

Once the tape has made one complete pass around the rims, smooth with a finger so the tape becomes more closely moulded.

24'' of tape will allow for 2 turns around the filter rims, with a small amount of excess.

If the tape becomes puckered whilst adhering, either smooth out with finger or undo tape slightly.

Pins, Safety Harness -
Rubber Band Affixing container -
Rubber Patches General facepiece repair Any facepiece with small tears or perforations can be repaired with locally purchased rubber patches or rubber solution. Repair kits for bicycle tyres may be used.

No repair should be attempted if the tear extends to the edge of the facepiece or if the tear occurs within 1/4 inch of the eye panel.

In the case of slits - the rubber patch should be no less than 1/4 inch longer than the slit at each end.

In the case of punctures that can only be seen by stretching the facepiece - a circular patch 5/8'' in diameter is adequate.

If prepared patches are not available, a patch of rubber may be cut from another badly damaged GCR facepiece.

Vulcanising the rubber is not to be attempted.

All patches should be placed on the outside of the facepiece.

Rubber Solution General facepiece repair As above
Valve, Inlet No.1 Replacement of inlet valve Lift old valve off stud, and fit the new valve by stretching the hole in the valve over the stud.

Ensure valve is sat firmly on the base of the stud.

Gas Drill for General Civilian Respirator[]

As soon as 'GAS' alarm is recieved:

  1. Hold breath, remove spectacles and/or headgear.
  2. Pick up the respirator by the straps, with thumbs underneath straps.
  3. Thrust chin into respirator and draw straps over head as far as they will go.
  4. Adjust as necessary. Pick respirator container back up and put headgear back on. 

When the threat of gas has believed to have passed:

  1. The air must be tested before fully removing the respirator, in order to do this, gently lift one side of respirator with two fingers and sniff.
  2. If gas is detected or if in doubt, put respirator back on fully.
  3. Exhale strongly to remove any gas that may have entered the mask during testing. 
  4. If no gas is detected, remove respirator and put in container. 

Supply and Politics of the General Civilian Respirator[]

In October 1935, a memorandum sent to the Defence Requirements Committee by the Chemical Defence Research Department suggested that the number of GCRs required would range in at some 30 million. This number was reached by excluding the civil population residing in the extreme South, West and North-West of Britain - these particular populations were excluded as it was believed the prospect of a gas attack in these areas was considered low and thus did not warrant issue of respirators. The CDRD secured overall design authority for the GCR and agreed with the Home Office that by the end of 1936 they would have finalised the GCR design, however, by July 1936, the Home Office expressed its satisfaction with the GCR design. Approval was given to the Defence Policy and Requirements Committee to speed up production of the GCR - with the aim of at least 5 million GCRs by the conclusion of 1936. Although the GCR programme had been in place since 1935, one of the glaring issues surrounding the GCR program stemmed from a lack of a suitable assembly location. This was rectified when a disused cotton mill in Blackburn, Lancashire passed into Government ownership on 13th July 1936. Work began dismantling the old weaving equipment and refurbishing the mill for respirator assembly and on 30th November, the mill began assembling the GCR. Mr. George Lloyd (then the Home Secratary) formerly opened the Blackburn mill on 12th January 1937. 

The Blackburn mill had assembled 750,000 GCRs by February 1937 and could boast a weekly production rate of 250,000 GCRs. Whilst a weekly production of 250,000 or 1 million per month seems satisfactory, Mr. G Lloyd stated previously on the 12th November 1936 that he originally expected  a monthly production of 2 million.  The original October 1935 memorandum (30 million GCRs) was once again revised to 40 million GCRs with an ideal completion date of summer 1938. The Blackburn mills' weekly production rate was greatly increased throughout 1937 and by June 1937, 9 million GCRs had been produced. On 30th November 1937, Mr. G Lloyd stated to the House of Commons that the Blackburn mill had a rate of 650,000 per week - 150,000 more than the estimated 500,000 per week.

By the opening of 1938 Britain had secured some 25 million GCRs. Once again, the total number of GCRs required was revised. Due to the difficulty of determining the size required for each individual and the potential of replacements for damaged respirators, it was agreed that a 20% reserve stock was required. It was also decided that no part of Britain could be considered truly safe from gas warfare, thus all civilians (some 44 million) were to be given GCRs. The number of GCRs required was thus 52.8 million (44 million for each civilian and a 20% (8.8 million) reserve stock). Due to the new production goals, approval was given for production of 45 million GCRs by the end of 1938. On the 15th June 1938, Mr. Lloyd stated the following:  Tests which have been made in the assembly of respirators show that 30,000 can be assembled by 29 persons in eight hours; and provided the work of distribution is carried out concurrently with that of assembly it should be completed shortly afterwards.

During a Commons debate on 3rd November 1938, Sir S Hoare noted that some 40 million respirators had been made with around 38 million distributed, and by March 1939, a report by Sir J Anderson stated In the matter of civilian respirators, we have taken delivery of 50,000,000 respirators and their containers' Despite ample GCR stock as early as 1939, GCR production continued and eclipsed the 52.8 million deemed necessary. The 1989 Porton Down study on respirator canisters mentions that G.C. Trotman claims 93 million GCR and CD respirators were produced. 

The estimated cost of the GCR programme was around £4 million. 

The distribution of the GCR remained lopsided, with major key areas such as London receiving their masks as an overall priority. Government planners concluded that the best course of action was to distribute masks in such a manner that a central reserve for key areas was built up first, rather than a uniform distribution programme. As late as June 1939, it was noted that Cornwall, Cumberland, Devonshire and Gloucestershire were still lagging in fully distributing all necessary respirators. Echoing this, Lieutenant-Commander Agnew also noted that there was still a great deficiency of all kinds of A.R.P. equipment in major industrial areas of Cornwall. 

The GCR attracted some negative attention when Wing-Commander E. J. Hodsoll, a Home Office official, stated publicly on 23rd October, 1935 that the civilian respirator would only offer protection from war gases for a minuscule 15 minutes. The negativity surrounding the GCR would even reach the House of Commons - on the 27th February 1936, Mr Gallacher questioned Mr G Lloyd, asking him if the GCR used cardboard and string and later asking  whether he (Mr. G Lloyd) is satisfied that this mask will afford genuine protection against possible gas attacks and not merely an illusion of protection Lloyd defended the GCR programme stating that Hodsolls' proclamation of 15 minute protection was, while not technically incorrect, based on the highest concentration of gases. That is to say, the GCR would provide 15 minute protection against very high concentrations of war gases and in Mr Lloyds opinion, such high concentrations were unlikely to be experienced by the civil population. During the same session, Mr. Lloyd stated that under expected concentrations, the GCR would provide satisfactory protection for several hours. 

ARP planning would undergo another nosedive in public relations when a group calling itself the 'Cambridge Scientists Anti-War Group' conducted scientific tests on various information provided by the government in relation to air-raid protection - chiefly the gas-proofing of rooms, respirator protection and government advice on extinguishing incendiary bombs. The group argued that from a 1937 study they conducted, looking at the rate of which gas may enter a supposedly sealed room, the government proposals for civil defence were wholly inadequate. During one Commons session, one Mr. Sorenson questioned other members if they were aware that the CSWAG have declared that there is no effective protection whatever? 

Government officials subsequently questioned the validity of the CSAWG studies - on 18th February 1937, Sir Nicholas Grattan-Doyle pressed Mr. Lloyd, asking him if he intended to reassure the public about the robustness of government air-raid planning in light of CSWAGs criticism. Mr. Lloyd countered that the CSWAG studies were not valid as in his view, the studies were conducted and interpreted along purely theoretical lines. Mr. Lloyd furthered his criticism of CSWAG by stating the official government studies were done based upon carefully conducted experiments employing actual war gases.  In reference to CSWAG comments on government recommendations on gas-proofing rooms, Mr. Lloyd reiterated his belief that the official gas-proofing methods were greatly adequate. Earlier on 15th February 1937, Mr. Lloyd had also questioned the CSWAGs motives for attacking government plans - noting that it was difficult to determine if CSWAGs criticisms were scientifically or politically motivated. CSWAGs studies also came under fire from other academics such as Jack Haldane (author of Callincus: a defence of chemical warfare, (1925), who also pondered the accuracy of the methods employed by CSWAG.

Whilst a collector or casual observer dealing with the GCR might be temped to chastise the government, noting its pitifully thin poor quality rubber or its questionable celluloid eyepiece, one must consider that the GCR design was, in Flight-Lieutenant Challens' words (1943): designed simply for wearing while people go to a refuge.


The GCR was packaged in outer cardboard cartons of 150 facepieces. Each carton contained inner boxes of 25 facepieces. Each outer carton was equipped with a coloured gummed strip. The colour indicated the size of the GCR facepiece. The colours and dimensions are as follows:

White strip - Large GCR facepiece ( outer carton dimensions - 19.75 in x 16.75 in x 9.5 in) Weight - 31lbs

Red strip - Medium GCR facepiece (outer carton dimensions - 19.75 in x 16.75 in x 8.75 in) Weight - 28lbs

Blue strip - Small GCR facepiece (outer carton dimensions - 19.75 in x 16.75 in x 8 in) Weight - 26.5lbs

Filters for the GCR were packaged in cardboard cartons. Each carton contained 10 cardboard tubes, with each tube containing 5 filters (G.C. Mk II). Dimensions of filter cartons were - 20 in x 15 in x 8.25 in. Each filter carton weighed 40lbs.

Rubber bands for GCR were supplied in groups of 10.

50 inlet valves supplied in cylinders.

Cardboard boxes for GCR were issued in groups of 100 (unfolded). A piece of plywood measuring 10.75 in x 5.375 in x 9.25 in was used to roll the boxes into shape.


Example of a handmade/private purchase cover. Judging by the drawn red cross emblem, the previous owner was possibly connected to a First Aid Party organisation

The GCR was issued in a cardboard box, with instructions printed on the inside lid. However, due to private purchases and handmade box covers, there exist many different varieties of storage containers for this mask. The main reason for after-market storage solutions was due to the cardboard being thin, poor quality and a lack of resistance to general wear and tear.

Sloan's patent drawing for GCR container

Women had special handbags where they could carry their masks. After the war, unfortunately, many of these masks were cut, at the filter end to make an elastic band which was used as a makeshift slingshot by children.

Elkes biscuit company produced tins for respirator storage, often with painted lines such as 'TAKE CARE OF YOUR GAS MASK' and 'STORE IN A COOL PLACE'. These tins were red and sported a metal opening/closing latch and carrying handle. It should be noted that these tins did not replace the standard issue carboard box, but instead the box was placed inside the tin to protect it.

Home Guard units were initially issued the same GCR in the standard cardboard box. Predictably, the cardboard did not survive long during the rigours of training, thus Home Guard units were issued their respirators in cylindrical brown metal tins. These tins were lined with soft fabric and featured a twine carrying strap. Some respirator care instructions were printed on the lids inside. This particular container was patented by William N. Sloan on the 7th October 1938. This container was also presumably available for purchase by private citizens.

In addition to the above, E.I. & Co made a octagonal respirator storage tin in the same brown metal as the Home Guard tins. This particular tin opened/closed on hinges. The tins sides' were flanked by metal loops to attach a shoulder strap to.

End of compulsory carrying[]

On 12th October 1939, The Home Secretary announced that the Government no longer considered the carrying of masks in reception areas as 'essential'. This action was motivated by a number of complaints garnered from civilians who were annoyed by over-bearing wardens harassing those who didn't have their masks.

Flapper/Flutter valve[]

Flutter Type Valve General Civilian Mask from Johannes' collection (

Some GCR masks were fitted with an additional flapper valve, similar to the Civilian Duty Respirator. These particular masks were issued to those suffering respiratory problems, mostly asthmatics. They are otherwise identical to the regular GCR and were issued in the same box.

Ear Protector Accessory[]


On 11th November 1938, an inventor named Werner Daya filed a patent for an aftermarket device that, when used in conjunction with the GCR would provide protection for the users' ears. Daya noted that German civilian masks encapsulated the entire head and thus protecting the ears from gas, whereas the GCR left the ears exposed.

The ear device was constructed of a suitable elastic, to which one end has a circular band (see Fig 2, part '1') which slides over the filter assembly. The ear caps (see Fig 1/2, part '6') were constructed of a wire frame covered with rubber or other resilient material, Werner's patent also included the possibility of the ear caps being constructed with interal ear plugs made of sponge (the patent drawing does not show this particular addition). Ensuring a gas-tight fit, the device had a buckle system (see Fig 2, parts '15' and '16') which could be adjusted for the user.

Commonwealth Variants[]

This mask was issued to Commonwealth countries such as; Malta, Canada and New Zealand, all having their own variations (except for Malta). It was made by two main companies Seibe Gorman and Avon. Pictures of this mask's variations can be found in the gallery below.


References[] (Johannes' collection)

'Protection against Gas and Air raids, Pamphlet No.2 'RESPIRATORS' (Canadian reprint, 1941)

'Personal Protection against gas' (1936 Ed.)

'Personal Protection against gas' (1938 Ed.)

ARP Cigarette Cards (1938, Wills' Tobacco Company)

'Improvements in respirators, gas masks' (John A. Sadd, 1935, 1936) (Patent)

'Asbestos in World War II Respirator Canisters' (Porton Down, 1989)

'An improved box for a gas-mask' (William N. Sloan, 1938) (Patent)

History of the Second World War - Civil Defence (T.H. O'brien, 1955)