Give the viewer instructions on how to avoid the hazard. Bias the
sign towards action. Signs are really advertisements for safety. They
need to be persuasive.
Use direct words. "Wear Hard Hats" is better than "Hard
Hats are Required". Avoid difficult to interpret adverbs: "Respond
within one minute" is better than "Respond quickly."
Although the use of a symbol is strongly encouraged in order to better
communicate hazard information across language barriers, more and
more warnings themselves are now shown in two languages.
Signs and labels shall be of the size to allow the first line of the
message be read from sufficient distance to avoid the hazard.
Click
here
for greater guidance on legibility and letter height.
The new ANSI standard for safety signs emphasizes custom design. It
suggests that you add an Action statement, consequences,
a symbol, use mixed case and, in many situations, add emergency information.