What do the colours and shapes of safety signs mean?
Every safety sign pairs a shape with a colour, so a person can read its meaning from across a room before they can read the words. The same pattern is used in AS 1319 and in the ISO 7010 symbol set.
| Sign type | Shape and colour | What it tells you | Examples |
|---|---|---|---|
| Prohibition | Red circle with a diagonal bar, black symbol on white | Do not do this | No smoking, no entry, no forklifts, no mobile phones |
| Warning | Yellow triangle with a black border and symbol | Be careful, a hazard is present | Electricity, slippery floor, forklift crossing, hot surface, overhead load |
| Mandatory | Blue circle with a white symbol | You must do this | Wear eye protection, hearing protection, a hard hat, gloves or a mask |
| Safe condition | Green rectangle or square with a white symbol | A safe place or a way out | Emergency exit, first aid, emergency shower, assembly point |
| Fire equipment | Red square with a white symbol | Where fire equipment is | Fire extinguisher, hose reel, fire alarm call point |
| Danger | Red oval with white lettering | A serious hazard, often a lock-out or tag-out notice | Danger, do not operate; high voltage |
What are the most common hazard symbols at work?
The warning triangle is the family people meet most. A few symbols cover most workplaces: electricity (a lightning bolt), slips and trips (a falling person), forklifts and moving vehicles, hot surfaces, laser and radiation, biological hazards, falling objects, moving machinery that can crush or entangle, and a general exclamation mark for any hazard that has no picture of its own. Under ISO 7010 each symbol has a code, such as W001 for a general warning and W012 for electricity, which helps when you order, audit or record a sign.
What are the nine GHS hazard pictograms?
The Globally Harmonized System of Classification and Labelling of Chemicals, called GHS, uses nine pictograms. Each sits in a red-bordered diamond on a chemical label and safety data sheet.
| Pictogram | Meaning | Typical products |
|---|---|---|
| Flame | Flammable gases, liquids, solids and aerosols; self-heating | Solvents, paints, aerosols |
| Flame over circle | Oxidiser, which can feed a fire | Pool chlorine, some cleaning agents |
| Exploding bomb | Explosive, self-reactive or organic peroxide | Some industrial peroxides, fireworks |
| Gas cylinder | Gas under pressure | Compressed gas, LPG, refrigerants |
| Corrosion | Corrodes metals or burns skin and eyes | Acids, caustic cleaners |
| Skull and crossbones | Acute toxicity, fatal or toxic if swallowed, touched or breathed | Some pesticides, cyanides |
| Exclamation mark | Irritant, skin sensitiser, harmful, or narcotic effects | Detergents, many solvents |
| Health hazard | Carcinogen, mutagen, respiratory sensitiser, or serious long-term effects | Some solvents, isocyanates |
| Environment | Harmful to aquatic life | Some pesticides and fuels |
Australia's Work Health and Safety rules adopt the GHS, but check the current requirements for your jurisdiction, because some elements, such as the environment pictogram, are optional here. Chemical transport uses a related but different set of diamond labels from the Australian Dangerous Goods Code.
How do you read a hazard sign correctly?
- Look at the shape first: circle means an instruction, triangle means a warning, rectangle means information.
- Check the colour: red is stop or fire, yellow is caution, blue is a must-do, green is safe.
- Read the picture, then the words underneath; a good sign has both.
- Ask what the sign expects you to do next, and whether you can do it from where you stand.
Where should hazard signs go, and how do you keep them useful?
Put a sign where the person needs the message: at the entry to the area, at eye height, in good light and not behind racking or a door. Fewer signs work better than many, because a wall of signs trains people to ignore all of them. A sign also does not replace a control. In the hierarchy of control, signage is an administrative measure, so remove the hazard, guard it or change the work first, and use the sign to cover what remains.
How do you audit your site's hazard signs?
Walk each area and check four things: the sign is still needed, it is the correct standard sign and colour, it is legible and not faded or damaged, and it is in the right place. Record any missing or wrong sign as an action with an owner, and re-check after changes such as a new layout, a new chemical or a new machine. Many sites add a sign check to the monthly area inspection and to the pre-start walk when work changes.
Step by step
- Walk the area. Go to each work area, store and entrance with a list of the hazards in that area.
- Match hazards to signs. For each hazard, check that a standard AS 1319 or ISO 7010 sign is present in the right colour and shape.
- Check condition and position. Replace signs that are faded, damaged or hidden, and move any that cannot be seen from the point of entry.
- Check chemical labels. Compare container labels and safety data sheets for the right GHS pictograms and signal words.
- Record and close actions. Log missing or wrong signs as actions with an owner and date, and check them again at the next inspection.
A worked example
A food plant added a new cleaning chemical on the night shift and relied on the old corrosive sign on the store door. During a monthly area inspection the team leader found that the new product carried a different set of pictograms, including a skull and crossbones, while the store door still showed only corrosion. She logged an action, the store sign was changed within the week, and the team added a sign check to the standard list whenever a new chemical is approved.