Box respirator gas mask

Instruction leaflet to explain to soldiers how to use a box respirator for protection during a gas alarm, (Catalogue ref: WO 142/183)


Directions of use of small box respirator.

At ordinary times, the haversack containing the Box Respirator is to be carried slung over the right shoulder, WITH THE FLAP FASTENERS NEXT THE BODY.

  • To Change to the Gas Alert Position:
  • Pass the left arm backwards through the sling so that the haversack hangs in front of the body.
  • Raise the haversack on to the chest by pulling the sling with the left hand until the brass stud on the sling is low enough to button on to the leather tab on the left side of the haversack.
  • Take the coil of whip cord out of the haversack, pass it through the ring pointing to the right of the haversack, round the body, and tie it firmly to the ring pointing to the left of the haversack.
  • Unbutton the snap fasteners, but keep the flap closed towards the body to protect the respirator from wet.
  • Unfasten the buckle of the tape which keeps the box in the haversack, and lift out the box; remove the indiarubber stopper from the bottom and then put the box back in the haversack.
  • On the Sounding of the Gas Alarm:
  • Open the haversack by pulling the cover forward, and grip the mask with the right hand.
  • Take the mask out of the satchel and seize it with both hands, the fingers gripping the edge of the mask and both thumbs pointing inwards and upwards UNDER the elastic. Throw the chin well forward ready to enter the mask.
  • Push the chin well into the mask and at the same time draw the elastics over the head AS FAR AS THEY WILL GO, i.e. till the central tape is tight.
  • Holding the metal mouth tube in the right hand outside the mask, push the rubber mouth piece well into the mouth and draw it forward so that the rubber flange is between the teeth and the lips, and grip the two small rubber projections with the teeth. Then start breathing in and out through the tube.
  • Open the nose clip by pinching from the outside the circular wire spring below the goggles; push the clip buttons on to the lower part of the nose and release the spring, making sure that the nostrils are closed.
  • Complete the fitting of the mask by pulling it well on over the jaw and by smoothing the edge all round the face.
  • Do not attempt to speak while wearing the respirator except in case of necessity.
  • If it is necessary to speak, breathe in deeply, grasp the metal tube outside the mask and carefully remove the mouthpiece from between the lips – care being taken not to move the nose-clip.
  • After speaking, immediately replace the mouthpiece and make certain that the nose-clip is properly adjusted.
  • If the eye-pieces become dull they can be cleaned by inserting the forefinger into the pockets alongside the goggles and wiping the inside of the windows. The eyepiece is held with the other hand while this is being done.
  • If the nose-clip slips off the nose, replace at once.
  • After use, carefully dry the mouthpiece and eye rims from the inside and also inside surface of the mask, so as to remove the condensed moisture resulting from the breath.

Replace the stopper in the bottom of the box when the gas-alert is no longer on.

Extract from notes from the War Office [Chemical Warfare Department] about the box respirator gas mask which explain how it worked, (Catalogue ref: WO142/183)


The small box respirator.

General description.

The small box respirator consists essentially of a box connected by means of a breathing tube to a mask constructed to fit closely over the face. When the respirator is in use, all air inhaled by the wearer passes through the box along the breathing tube into the wearer’s mouth. The box contains granules which absorb the poisonous gases, so the air passing along the breathing tube is pure.

Exhaled air, on the other hand, does not pass through the box. It is diverted through a side tube and expelled from the respirator by the working of two valves, one, in the bottom of the box opening on inspiration and closing on expiration, and the other, situated on the breathing tube just outside the face-piece, opening on expiration and closing on inspiration.

The mask, besides containing the mouth piece, is provided with goggles and a nose-clip, and fits tightly across the forehead, down the sides of the cheeks, and under the chin. It is held in position by elastics which are slipped over the head and arrested in the proper position by a head tape.

The fabric of the mask is impervious for reasonable lengths of time to all gases, and therefore provides protection for the eyes against lachrymation [watering]. The goggles, if steamy, can be wiped by inserting the forefingers in the temple pockets provided in the mask. The nose must be closed by the clip in order to prevent any breathing into the face piece and to ensure that inspiration and expiration take place only through the mouth-tube. The apparatus is carried in a special haversack which is divided into two compartments, one containing the box and the other the mask.


THE BOX. – This is an oval, corrugated metal tin. In the bottom is inserted a push-in lid carrying the inlet valve: this can be prised out for inspection. The valve consists of a circular rubber disc fitted on a stud in the centre of a perforated metal plate and covering the perforations. On inspiration, the rubber disc lifts, allowing air to enter; on expiration, the disc is pressed down, closes the perforations and prevents expired air from passing through the box. In the bottom of the box is soldered an arch-shaped brass gauze, concave to the base of the box. The chief function of this gauze is to equalise the resistance offered to the passing of air through the middle and outer portions of the contents, and thus to ensure that the air passes uniformly through the whole of the purifying chemicals. The filling of the box is as follows:-

From bottom to top:

  • A layer of special charcoal in small granules
  • A layer of strongly alkaline and oxidising granules
  • A second layer of special charcoal in small granules. The layers of granules are separated by iron wire gauze: on the top of the last layer of charcoal are placed
  • A piece of cheese-cloth soaked in paraffin wax
  • Two pieces of towelling moistened with glycerine
  • An iron wire gauze, strongly ribbed to prevent the ends bending upward.

The moistened towelling prevents any dust from being drawn up the breathing tube into the wearer’s mouth: the waxed cheese-cloth prevents the glycerine draining into the charcoal.

The entire contents of the box are held in position by two strong springs pressing down on the iron gauze (3).

The lid is soldered on and provided with a metal outlet tube to which the breathing tube is fitted.

The box, so constructed, protects against all poison gases, including lachrymators [chemical that causes tears to flow]

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