CAUTION sign

How to read it

OSHA’s sign rule, 29 CFR 1910.145, says caution signs warn against potential hazards or caution against unsafe practices, and indicate a possible hazard. Its tag rule keeps caution tags for minor hazard situations, where a non-immediate or potential hazard or unsafe practice presents a lesser threat of injury. Yellow is also OSHA’s colour for marking physical hazards such as tripping, falling and being “caught in between”.

Also searched as: ansi caution, caution signal word.

Old-style and ANSI-style CAUTION signs

The two designs reverse the colours of the header. On the older OSHA design, from ANSI Z35.1-1968, the sign is yellow with a black upper panel, the word caution is in yellow letters on that panel, and the rest of the wording is black. On the ANSI Z535 design the word CAUTION is in black letters on a yellow panel. OSHA’s rules have accepted both since 2013.

Look-alikes

A WARNING header is orange, one step up the scale, for hazards that could cause death or serious injury; the chair of the ANSI colour subcommittee says that orange must not look yellowish, so that it isn’t confused with the yellow of CAUTION. The yellow warning triangle of ISO 7010 uses yellow too, as a triangle with a black pictogram and no signal word.