Smoke 21 : Solid or liquid particles 0.3 to 0.5 in diameter. A suspension of particles in a gaseous medium. A substance used in warfare for screening purposes
US Army Center for Health Promotion and Preventive Medicine CHPPM, TG 204 Glossary of Terms For Nuclear, Biological, and Chemical Agents And Defense Equipment (Section 5 - Chemical Terms), MD, USA 2001. http://www.au.af.mil/au/awc/awcgate/army/tg204.pdf , (DfnsEqu/Chem - Amer) {490}