The material in this Article is extracted from Chapter 16 (Human Factors and Ergonomics) of the book Plant Design and Operations.

Guidance as to the types of signs and their meanings is provided below.

Prohibition

Prohibition signs mean "You must not" or "Do not do . . ." or "Stop". Signs of this type have a red circle, a white interior and a red bar, as illustrated in Figure 16.4.

Figure 16.4
Prohibition Sign