This historical 1943 image, which was provided by the Center for Disease Control's (CDC), National Institute for Occupational Safety and Health (NIOSH), depicted a number of men engaged in the process of filling explosive ammunition shells with molten TNT (trinitrotoluene) inside a military ordnance plant. Seen here, were three men who were plant employees, and two Public Health Service (PHS) officers, who were observing, taking notes, and acquiring air samples, which they'd later test for the presence of the toxic TNT. Trinitrotoluene will irritate the skin upon contact, and actually will change the skin's color to a bright yellow-orange. Prolonged exposure leads to liver damage, anemia, enlargement of the spleen, and a compromised immune system, to name a few of its negative effects. TNT is also a known carcinogen. Neither the PHS officers, nor the factory employees wore any filtered breathing masks.
CDC/ Barbara Jenkins, NIOSH
November 4, 2012