Hot surface warning sign (W017)

How to read it

ISO 7010 registers W017, “Hot surface, warning”, a warning sign in ISO 3864-1’s sense: one that indicates “a specific source of potential harm”. On equipment the lines appear as symbol 5041 of IEC 60417, “Caution, hot surface”, which an Epson manual gives as meaning that the marked item can be hot and should not be touched without taking care.

Also searched as: caution hot surface, heat warning symbol, hot plate symbol, hot surface symbol, hot symbol, IEC 60417-5041, W017.

Where the symbol came from

Geoffrey Peckham, writing in In Compliance Magazine, traces the three wavy lines to an IEC symbol for heat on function and control buttons. When ISO made a warning sign for hot surfaces, the IEC image went inside the standard black-banded yellow triangle. He notes that “CAUTION – HOT” in words alone is a commonly posted message.

In the British regulations

The 1996 regulations have no hot surface sign. Their nearest is “Flammable material or high temperature”, a flame in a triangle, with a note that it is for high temperature in the absence of a specific sign. ISO 7010 splits the two: W017 for a hot surface and W021 for flammable material.

Look-alikes

The low temperature sign, W010, is the cold counterpart: a snowflake in the same triangle. A flame in a triangle is W021, flammable material, and the GHS flame on chemical labels is a pictogram outlined in red, Kansas State University’s safety office notes, not a yellow triangle.