Prohibition Safety Sign FAQs
Written by the Technical Team at Caledonia Signs
Last reviewed: July 2026
Welcome to the Caledonia Signs Prohibition Signs Knowledge Centre
Prohibition safety signs play an important role in workplace safety by clearly communicating actions and behaviours that are not permitted. They help prevent unsafe activities, protect employees, visitors, and contractors, and ensure that important workplace restrictions are understood. From factories and warehouses to construction sites, offices, laboratories, and public buildings, prohibition signs provide a simple and effective way to communicate safety rules.
Understanding when and how to use prohibition safety signs can raise many questions, including what the signs mean, where they should be displayed, which regulations apply, and what types of restrictions they communicate. Knowing the correct colours, symbols, and applications helps businesses choose the right signage to manage risks and maintain a safer working environment.
This page answers some of the most frequently asked questions about prohibition safety signs, including UK regulations, BS EN ISO 7010 standards, sign symbols, common examples, placement guidance, and the consequences of failing to display required safety signage. Whether you manage a warehouse, factory, construction site, office, or commercial property, this guide provides practical information to help you understand and use prohibition signs effectively.
Effective prohibition signage should form part of a wider health and safety system that includes risk assessments, employee training, safe working procedures, and appropriate control measures. By displaying clear, compliant prohibition signs in the correct locations, businesses can reduce unsafe behaviour, improve safety awareness, and create a safer environment for everyone.
What are prohibition safety signs?
Prohibition safety signs are workplace signs that indicate an action or behaviour must not be carried out because it could create a safety risk or breach workplace rules. Their purpose is to clearly communicate restrictions and prevent people from carrying out activities that may cause injury, damage, or create unsafe conditions. They are commonly used in workplaces, public buildings, and industrial environments to help control risks and maintain safe working practices.
Prohibition signs are easily recognised by their red circular border with a diagonal red line across a black pictogram on a white background, following the principles of BS EN ISO 7010 safety signage. The red circle and slash indicate that something is prohibited, while the pictogram shows the specific action or behaviour that is not allowed. This standardised design allows people to understand restrictions quickly, even where different languages are spoken.
Common examples of prohibition safety signs include No Smoking, No Entry, No Access for Unauthorised Persons, No Mobile Phones, Do Not Touch, and No Open Flames. These signs are frequently used in factories, warehouses, construction sites, laboratories, offices, and public areas where certain activities could create hazards or interfere with safety procedures.
In the UK, prohibition safety signs form part of effective workplace safety communication and should be used where restrictions are needed to reduce risk. When correctly selected, positioned, and maintained, prohibition signs help reinforce safety rules, prevent unsafe actions, and support a safer environment for employees, visitors, and contractors.
What regulations apply to prohibition safety signs in the UK?
In the UK, prohibition safety signs are covered primarily by the Health and Safety (Safety Signs and Signals) Regulations 1996. These regulations require employers to provide suitable safety signs where risks cannot be adequately controlled through other measures. Where a specific action or behaviour needs to be prevented to protect people from harm, an appropriate prohibition sign should be displayed to clearly communicate the restriction.
Prohibition safety signs should follow recognised design standards, including BS EN ISO 7010, which provides internationally recognised safety symbols and pictograms. These signs typically feature a red circular border with a diagonal red line over a black pictogram on a white background, making them immediately recognisable as instructions that something is not permitted. Examples include No Smoking, No Entry, No Open Flames, and No Unauthorised Access signs.
Employers should determine where prohibition signs are required through suitable workplace risk assessments and ensure they are displayed in locations where the restriction needs to be understood before people carry out an unsafe action. Signs should be clearly visible, easy to understand, and maintained in good condition so that safety messages remain effective.
Although prohibition signs are an important part of workplace safety management, they should be used alongside other risk control measures such as safe working procedures, training, supervision, and physical safeguards. Correctly selected and installed prohibition safety signs help businesses communicate restrictions clearly, support UK health and safety responsibilities, and reduce the likelihood of unsafe behaviour.
Where should prohibition safety signs be displayed?
Prohibition safety signs should be displayed in locations where people need to be clearly informed that a specific action or behaviour is not allowed. Signs should be positioned before the point where the prohibited activity could take place, giving employees, contractors, and visitors enough time to understand the restriction and comply with the requirement. Correct placement helps prevent unsafe actions before they occur.
Common locations for prohibition signs include entrances to restricted areas, access points, machinery zones, storage areas, hazardous locations, and areas where specific activities could create a risk. For example, No Smoking signs should be displayed in areas where smoking is prohibited, No Entry signs should be placed at unauthorised access points, and No Mobile Phones signs may be required in areas where phone use could affect safety or equipment operation.
Prohibition signs should be installed where they are clearly visible, well lit, and not hidden by doors, equipment, stored materials, or other workplace items. In larger workplaces such as factories, warehouses, and construction sites, additional signs may be needed along routes or near specific hazards to ensure the restriction remains clear throughout the area.
The number and location of prohibition safety signs should be determined through a suitable risk assessment and reviewed whenever workplace conditions or procedures change. Using correctly positioned signs that follow recognised standards such as BS EN ISO 7010 helps ensure restrictions are communicated effectively and supports a safer environment for employees, visitors, and contractors.
Caledonia Signs Expert Tip: Use Signs at the Point Where the Restriction Starts
Prohibition signs are most effective when they are displayed before someone reaches the area or activity that is not permitted. For example, place “No Entry” signs at restricted access points, “No Smoking” signs where the restriction begins, and “No Mobile Phones” signs before entering areas where phone use could create a safety risk. This gives people the opportunity to understand and follow the instruction before they enter the restricted zone.
Always use clear, BS EN ISO 7010-compliant prohibition signs with the recognised red circle and diagonal line symbol, and ensure they are positioned where they can be easily seen. Regularly check signs for damage, fading, or obstructions, and update them whenever workplace layouts, processes, or safety procedures change. A well-placed prohibition sign helps prevent unsafe actions before they happen.
What types of instructions do prohibition safety signs communicate?
Prohibition safety signs communicate instructions that certain actions, behaviours, or activities must not be carried out because they could create a safety risk or breach workplace rules. Their purpose is to prevent unsafe behaviour by clearly showing what is not permitted in a particular area. These signs provide an immediate visual reminder to employees, contractors, and visitors about restrictions that must be followed.
Common prohibition instructions include No Smoking, No Open Flames, No Entry, No Unauthorised Persons, No Mobile Phones, Do Not Touch, and Do Not Operate Machinery Without Authorisation. These signs are commonly used in workplaces where certain activities could cause harm, interfere with safety procedures, damage equipment, or increase the risk of fire or accidents.
Prohibition signs are widely used in factories, warehouses, construction sites, laboratories, offices, healthcare environments, and public buildings. For example, a No Smoking sign may be displayed near flammable materials, a No Entry sign may restrict access to hazardous areas, and a No Pedestrians sign may prevent people entering vehicle operating zones.
Recognised by their red circular border with a diagonal red line over a black pictogram on a white background, prohibition signs follow the principles of BS EN ISO 7010 safety signage. When correctly selected, displayed, and maintained, they help reinforce workplace rules, reduce unsafe actions, and support a safer environment for everyone.
What happens if a workplace does not display required prohibition signs?
If a workplace does not display required prohibition signs, it may increase the risk of unsafe behaviour, accidents, and injuries. Prohibition signs are used to communicate actions that are not permitted, such as entering restricted areas, smoking near flammable materials, or carrying out activities that could create a hazard. Without clear signage, employees, contractors, and visitors may not be aware of important safety restrictions.
In the UK, employers have a responsibility to manage workplace risks and provide suitable information, instruction, and warnings. Under the Health and Safety (Safety Signs and Signals) Regulations 1996, safety signs should be used where risks cannot be adequately controlled by other means. If a required prohibition sign is missing or unclear, a business may be failing to provide effective safety communication and could face enforcement action from relevant authorities.
Inadequate prohibition signage can contribute to workplace incidents, particularly in environments such as factories, warehouses, construction sites, laboratories, and industrial facilities. If a lack of signage contributes to an accident, businesses may face consequences including improvement notices, prohibition notices, prosecution, financial penalties, compensation claims, and reputational damage.
To reduce these risks, workplaces should identify areas where restrictions are needed through regular risk assessments and ensure appropriate prohibition signs are clearly displayed, maintained, and reviewed. Using correctly designed signs that follow recognised standards such as BS EN ISO 7010 helps businesses communicate restrictions effectively and supports a safer working environment.
What are common examples of prohibition safety signs?
Common examples of prohibition safety signs are signs that communicate actions or behaviours that are not allowed because they may create a safety risk or interfere with workplace procedures. These signs help prevent unsafe activities by providing a clear visual instruction that something must not be done. They are widely used in workplaces such as factories, warehouses, construction sites, offices, laboratories, and public buildings.
One of the most recognisable examples is the No Smoking sign, which is used in areas where smoking could create a fire risk or where smoking is prohibited by workplace policy or legislation. Other common examples include No Open Flames, used where ignition sources could create a danger, and No Mobile Phones, which may be displayed in areas where phone use could affect safety, equipment operation, or security.
Access control is another common use of prohibition signs. Examples include No Entry, No Unauthorised Persons, No Pedestrians, and No Access for Forklift Trucks signs, which help prevent people from entering hazardous areas or using routes that are unsuitable for them. These signs are particularly important in warehouses, factories, construction sites, and areas with vehicle movements or restricted operations.
Other prohibition signs may include Do Not Touch, Do Not Operate Machinery Without Authorisation, No Photography, and No Food or Drink where specific workplace rules or safety controls apply. Prohibition signs are recognised by their red circular border with a diagonal red line over a black pictogram on a white background, following the principles of BS EN ISO 7010. When correctly displayed, they help reinforce safety rules and reduce the likelihood of unsafe actions.
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