Personal protection against gas / issued by the Home Office (Air Raid Precautions Department).

Date:
1938
Catalogue details

Licence: Public Domain Mark

Credit: Personal protection against gas / issued by the Home Office (Air Raid Precautions Department). Source: Wellcome Collection.

    27/136 (page 17)
    CHAPTER III THE DETECTION-OPF. GASES 7. Principles of Gas Detection The rapid transmission of information that gas has been used, with its nature and details of the areas affected, is a very necessary factor of success in air raid precautionary measures. By gas detection is meant the recognition of the presence of gas and the identification of its type. The presence of gas may be detected in a number of ways :— (i) by the smell, (i) by immediate irritant effects, (ili) by visible signs, (iv) by chemical testing. Most gases hitherto used in warfare have either a dis- tinctive smell or a characteristic irritant effect on the eyes, nose or throat. In many cases also there will be visible indications of gas, such as the presence of a cloud or liquid splashes on the ground. To a large extent, therefore, reliance can be placed upon the senses, particularly the sense of smell, but chemical tests may be available in addition for the identification of particular gases. 8. Detection of the various Types of Gas Detection of tear gases Tear gases are easily detected owing to their im- mediate irritant effect upon the eyes. As many of the tear gases are persistent, and consist of dark brown liquids, care must be taken not to confuse gases of this group with blister gas contamination.