Safety Signs and Colours Explained: What Each One Means

Safety signs give quick, clear information about hazards and what people must or must not do. The Health and Safety (Safety Signs and Signals) Regulations 1996 require employers to use them where a risk cannot be avoided or adequately reduced in other ways, and to make sure employees understand what they mean.

The four main types of sign

Type	Shape and colour	Meaning	Examples
Prohibition	Red circle with a diagonal bar, black symbol on white	You must not	No smoking, no access, do not use mobile phones
Warning	Yellow triangle with a black border and symbol	Danger, be careful	Forklift trucks operating, electrical hazard, slippery floor
Mandatory	Blue circle with a white symbol	You must	Wear hard hats, wear eye protection, wear hi-vis
Safe condition	Green rectangle or square with a white symbol	Safety equipment or escape	Fire exit, first aid, emergency eyewash, assembly point

Fire equipment signs, such as those showing the location of a fire extinguisher, hose reel or call point, are white symbols on a red square or rectangle.

What the regulations require

Provide safety signs where the risk assessment shows a risk that cannot be avoided or adequately controlled by other means
Use signs that meet the regulations, including the standard colours and shapes. Signs to BS EN ISO 7010 meet these requirements.
Maintain signs so they stay visible and legible
Explain the meaning of signs to employees, along with what they should do
Use other signals where needed, such as illuminated signs, acoustic signals, hand signals and verbal communication

Signs are not a control on their own

A sign does not remove a hazard. It should support other controls in the hierarchy of controls, not replace them. Too many signs in one place can also mean none of them are read, so keep them relevant and remove ones that no longer apply.

Pipework and containers

Containers and pipework carrying hazardous substances must be labelled. Containers use the hazard pictograms from the classification and labelling rules, and pipework can be marked with the pictograms and the substance name at key points.

Hand signals

The regulations also set out hand signals, for example for directing lifting operations and vehicles. These include start, stop, emergency stop, raise, lower, and move in a direction. Banksmen and signallers must use the standard signals so that drivers and crane operators understand them. Our guide to construction traffic management covers vehicle marshalling on site.

Fire escape signs

Escape route signs show a running figure and a directional arrow on green, and must lead people all the way to a final exit. They should be visible in an emergency, which may mean illuminated or photoluminescent signs. The fire risk assessment should confirm they are in the right places.

Training that helps

Our safety hazards eLearning and health and safety induction eLearning cover safety signs for all staff. In construction, CITB’s Health and Safety Awareness course explains site signs. For managers, IOSH Managing Safely and the NEBOSH National General Certificate cover safety signs within the wider legal framework.

Frequently asked questions

What do the colours of safety signs mean?

Red means prohibition or fire equipment, yellow means warning, blue means mandatory and green means safe condition or escape.

What shape is a mandatory sign?

A blue circle with a white symbol.

Are safety signs a legal requirement?

Yes, where a risk cannot be avoided or adequately controlled by other means, under the Safety Signs and Signals Regulations 1996.

What standard do safety signs follow?

Signs to BS EN ISO 7010 meet the requirements of the 1996 regulations.

Read the source

The Health and Safety (Safety Signs and Signals) Regulations 1996; HSE L64, Safety signs and signals, guidance on the regulations; and BS EN ISO 7010, graphical symbols and registered safety signs. Facts checked on 6 October 2026.

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