Know how to use "fewer" and "less"? Find out.
phosgene phos·gene (fŏs'jēn', fŏz'-)
A colorless volatile liquid or gas used as a poison gas and in making dyes.
A colorless, volatile gas that has the odor of freshly mowed hay. When it reacts with water (as in the lungs during respiration), phosgene produces hydrochloric acid and carbon monoxide. It is used in making glass, dyes, resins, and plastics, and was used as a poisonous gas during World War I. Also called carbonyl chloride. Chemical formula: COCl2.