Warning (Hazard) Signs Explained
Yellow triangle signs warn people about a danger before they reach it, from live electricity to moving forklifts.
What warning signs mean
A yellow triangle with a black border and black symbol warns of a hazard. In South African catalogues these are often listed with WW codes under SANS 1186. The triangle points up, and the colour is chosen to be seen from a distance.
General warning
An exclamation mark: a hazard with no specific symbol.
Electrical hazard
A lightning bolt: risk of electric shock.
Forklift trucks
Vehicles moving in the area.
Common warning signs and where they go
| Warning | Typical places |
|---|---|
| Electrical hazard / high voltage | Distribution boards, substations, transformers, generator rooms |
| Forklift trucks | Warehouses, loading bays, aisles and pedestrian crossings |
| Slippery floor | Kitchens, wash bays, entrances on rainy days |
| Corrosive or toxic substances | Chemical stores, cleaning stores, labs, battery rooms |
| Flammable material | Fuel stores, paint stores, gas cylinder cages |
| Hot surface | Kitchens, boilers, pipes, presses and heat machines |
| Overhead load / crane | Workshops and yards with cranes or hoists |
| Trip hazard / uneven floor | Steps, ramps and changes in level |
| Guard dog / electric fence | Gates, walls and perimeter fences |
Using warning signs well
- Place the sign where people see it before they reach the hazard, not on top of it
- Do not overload a wall; too many signs together get ignored
- Add a text panel for visitors and contractors who may not know the symbol
- Combine with a mandatory sign when the hazard needs PPE, for example “electrical hazard” plus “wear insulating gloves”
- Replace faded signs; yellow fades in direct sun, so use UV-resistant material outdoors
Frequently asked questions
What do yellow warning signs mean?
A yellow triangle with a black border warns of a hazard nearby. It does not tell you what to do; it tells you to be careful.
What is the difference between a warning sign and a prohibition sign?
A warning sign (yellow triangle) tells you about a danger. A prohibition sign (red circle with a bar) tells you an action is not allowed.
Can I add my own text under a warning sign?
Yes. A supplementary text panel such as “Danger: high voltage” or “Forklifts operating” helps visitors understand the symbol. We print combined symbol-and-text signs to order.
Which warning signs does an electrical board need?
At least an electrical hazard warning sign. Many sites also add a “Danger: authorised persons only” sign and an electrical shock first aid poster. Your electrician or safety officer can confirm.
Order Your Signs Today
Express Print makes SABS-style safety signs on ABS, aluminium, Chromadek, Correx and photoluminescent vinyl, in Rivonia, Johannesburg. Tell us the sign codes and sizes and we will quote you.
