Chemical warfare

by Amos A. Fries; Clarence J. West

Protective Clothing

Protective clothing was an additional feature of the general program of protection. As far as factory protection is concerned, the use of protective garments was more or less of a temporary expedient and they were abandoned as fast as automatic machinery and standard practice made their use less necessary. It is likewise a question regarding their value at the front. It is very certain that the garments developed needed to be made lighter and more comfortable to be of much value to the fighting unit.

The first development of protective clothing was along the lines of factory protection. The large number of casualties in connection with the manufacture of mustard gas made it imperative that the workmen be protected not only from splashes of the liquid mustard gas, but also from its vapors. The first suit developed provided protection to the entire body. The ordinary clothing materials and even rubberized fabrics offered little protection but it was found that certain oilcloths were practically impermeable to mustard gas. The suit was a single garment, buttoning in the back, with no openings in the front, no pockets and with tie-strings at wrists and ankles. The head was protected by means of an aluminium helmet, supported by means of a head band resting on the head like a cap and slung from the inside of the helmet; this permitted slight head motions independent of the helmet. In order to provide cooling and ventilating and pure air breathing, the suit was inflated by pumping a considerable volume of air into the suit through a flexible hose long enough to permit considerable freedom of movement.

This suit had the very great disadvantage of limiting the range of motion to the length of the hose. Because of this, a Tissot type mask was used in place of the helmet and hose connections. The hood was made of the same special oilcloth as the suit, enveloped the head and neck and extended a short distance down the back and over the chest. The canister was slung on the left hip by an oilcloth harness and was kept from swinging by an oilcloth belt around the waist. The canister was much larger than the standard box respirator, had a much longer life with lower resistance and weighed about 3.5 lbs.

Fig. 80.—Impervious Overall Suit
for Mustard Gas.

Another type of impervious overall suit was developed which protected against mustard gas for over 100 minutes. The material was a cotton sheeting which was impregnated with linseed oil containing a suitable non-drying material, which was thoroughly oxidized in the fabric. These suits proved to be very uncomfortable, especially in warm weather, because they entirely prevented the escape of perspiration from the body.

Semi-permeable suits were then prepared, in which the cotton sheeting was impregnated or coated with a solution of gelatin and glycerine. The fabric was then “tanned” to render the gelatin insoluble in water. Such a suit is valuable for factory wear, but the impregnating material is easily leached out and the suit is therefore not recommended for field service.

This was built with an inside layer of dry cloth together with an outside layer of treated cloth to afford the necessary chemical protection against mustard gas. Work of fabrication consisted in treating the cloth with simplexene, cutting the suits to design and size, and sewing them together.

Treatment consisted in passing the fabric through a dye machine, then through the wringer rolls where the excess oil was expressed. The inner layer of dry cloth was found necessary, since the cloth was cut as soon as treated. Simplexene does not attain the maximum degree of “tackiness” for two or three days, owing to the presence in the oil of a small amount of volatile spirits. However, by allowing the cloth to air for 48 hours before cutting, the inner lining could probably be dispensed with.

The fighting suits were distributed among various detachments using mustard gas in field tests, and in other places where protection against vapor was needed and where field conditions were approximated. The tests showed that the suit gave satisfactory protection for considerable periods against mustard gas vapors. No other suit, equal both in porosity and protection, has yet been submitted, although samples furnishing better protection with much higher resistance have been examined. The protection of the simplexene suit is about 30 minutes against saturated gas. A large number of these suits were made and taken abroad for field tests at the front.