Electrical warning signs are used in workplaces, commercial buildings, factories, warehouses and construction sites to alert people to potentially dangerous electrical equipment and installations.

Two of the most commonly encountered messages are Danger Electricity and Danger High Voltage.

Both warn about electrical hazards, and both may feature the familiar black lightning bolt inside a yellow warning triangle.

However, the wording is not interchangeable in every situation.

A Danger Electricity Sign provides a general warning about an electrical hazard, while a High Voltage Sign specifically identifies a high-voltage risk.

So which should you choose for an electrical cupboard, switchgear room, industrial installation or workplace entrance?

This guide explains the differences, where each sign may be appropriate and what to check before buying electrical safety signs.

What Is a Danger Electricity Sign?

A Danger Electricity Sign warns people that an electrical hazard is present.

It is a general electrical safety warning that can be used where the risk needs to be clearly communicated without necessarily specifying a particular voltage.

These signs commonly feature a yellow triangular warning symbol containing a black lightning bolt.

The recognised electrical hazard warning symbol is identified as W012 in BS EN ISO 7010.

Where Are Danger Electricity Signs Used?

Depending on the installation and relevant risk assessment, they may be suitable for:

• Electrical cupboards.

• Electrical equipment enclosures.

• Plant rooms.

• Switchgear areas.

• Industrial machinery.

• Electrical distribution equipment.

• Relevant maintenance and testing areas.

The sign alerts people to the presence of an electrical hazard.

It does not, by itself, tell them the operating voltage, identify safe access arrangements or establish that equipment has been isolated.

When Should You Choose a Danger Electricity Sign?

A general Danger Electricity Sign may be appropriate where an electrical warning is needed but a more specific high-voltage message is not justified.

For example, a commercial building may have an electrical cupboard containing distribution equipment.

A Danger Electricity Sign could be a suitable warning, depending on the installation and access arrangements.

Buying tip: Choose the warning based on the actual electrical hazard, not simply the appearance of the sign.

What Is a High Voltage Warning Sign?

A High Voltage Warning Sign specifically warns about an electrical installation or equipment operating at high voltage.

These signs may feature wording such as:

• Danger High Voltage.

• Warning High Voltage.

• High Voltage Keep Out.

• Danger High Voltage Equipment.

• High Voltage Danger of Death.

The correct message depends on the installation, its hazards and the intended audience.

Where Are High Voltage Signs Used?

They may be appropriate at:

• High-voltage substations.

• Relevant electrical switchgear rooms.

• High-voltage equipment enclosures.

• Transformer installations.

• Industrial high-voltage equipment.

• Certain electrical testing facilities.

• Other locations containing high-voltage apparatus.

A High Voltage Sign provides more specific information than a general Danger Electricity notice.

What Counts as High Voltage in the UK?

In the context of the Electricity at Work Regulations 1989, high voltage generally means voltage exceeding 1,000 volts AC or 1,500 volts DC, measured between conductors or between a conductor and earth, as applicable.

This definition is useful when distinguishing high-voltage installations from lower-voltage electrical systems.

However, the appropriate signage still depends on the installation and the relevant safety requirements.

Important: Lower-voltage electrical equipment can also cause serious or fatal injuries. The absence of high voltage does not mean the absence of danger.

Danger Electricity vs High Voltage Signs: Key Differences

The key difference is specificity.

A Danger Electricity Sign warns that electrical danger exists.

A High Voltage Sign communicates that the danger involves high voltage.

Neither sign should be chosen without considering the actual installation.

Which Sign Should Be Displayed on an Electrical Cupboard?

Electrical cupboards are found in offices, schools, warehouses, factories, hospitals and other commercial buildings.

They may contain distribution boards, electrical controls or other equipment.

General Electrical Cupboards

Where a cupboard contains electrical equipment but is not a high-voltage installation, a Danger Electricity Sign may be appropriate.

Depending on the circumstances, an Electrical Cupboard notice or access restriction may also be useful.

High-Voltage Electrical Cupboards or Enclosures

Where equipment genuinely operates at high voltage, a suitable High Voltage Warning Sign may be needed.

Additional access restrictions and other precautions may also apply.

Should Every Electrical Cupboard Have a High Voltage Sign?

No.

Not every electrical cupboard contains high-voltage equipment.

Using a High Voltage Sign where the installation is not high voltage can communicate inaccurate information.

Choose signage that reflects the actual hazard.

Which Sign Is Best for a Switchgear Room?

Switchgear rooms can contain different types of electrical equipment.

Some contain low-voltage distribution equipment, while others contain high-voltage switchgear.

The correct warning should reflect the installation.

Low-Voltage Switchgear Rooms

A general Danger Electricity warning may be suitable where electrical risks need to be communicated.

Other notices may be appropriate depending on access restrictions and operational requirements.

High-Voltage Switchgear Rooms

A specific High Voltage Warning Sign may be appropriate where high-voltage equipment is installed.

These areas may also require controlled access and other safety arrangements.

Buying tip: Don't select a sign solely because the room is called a switchgear room. Check the equipment and its operating voltage.

Danger Electricity vs Danger of Death Signs

Another common question is whether to choose a Danger Electricity Sign or a Danger of Death Sign.

Both communicate serious electrical hazards, but the wording differs.

Danger Electricity

Provides a general warning that an electrical hazard exists.

Danger of Death

Emphasises that the hazard could have fatal consequences.

A Danger of Death notice may be used in relevant high-risk electrical environments, but it is not automatically required for every electrical installation.

The appropriate message should reflect the risk and applicable requirements.

Avoid selecting the most dramatic wording simply because it appears more noticeable.

The sign should accurately communicate the hazard.

Can Low Voltage Electricity Be Dangerous?

Yes.

Low-voltage electrical systems can cause electric shock, burns and fatal injuries.

The severity of an electrical incident depends on several factors, including:

• The electrical conditions.

• The current passing through the body.

• The path of the current.

• The duration of contact.

• The surrounding environment.

• The nature of the work being carried out.

This is why a Danger Electricity Sign can be important even where equipment is not classified as high voltage.

High voltage is not the only type of electricity that presents serious risk.

Which Electrical Warning Sign Should You Buy?

The following examples can help narrow down your choice.

These are examples rather than a universal list of legal requirements.

The correct signs depend on the installation, access arrangements and risk assessment.

Where Should Electrical Warning Signs Be Displayed?

Electrical warning signs should be positioned where people can recognise the hazard before encountering it.

Common locations include:

• Electrical cupboard doors.

• Switchgear room entrances.

• Equipment enclosures.

• Relevant plant room entrances.

• High-voltage installation boundaries.

• Appropriate approaches to electrical testing areas.

Consider the Direction of Approach

A sign should be visible to people approaching the hazard.

For example, a warning fixed to the inside of an electrical cupboard may not communicate the risk before the cupboard is opened.

Check for Obstructions

Avoid placing signs where they can be hidden by:

• Open doors.

• Stored materials.

• Machinery.

• Temporary equipment.

• Other notices.

Choose a Suitable Viewing Distance

The sign should be large enough to recognise from the distance at which people need to see it.

A small equipment warning may be suitable for close-range viewing, while a warning at an industrial entrance may need to be larger.

Choosing the Right Electrical Warning Sign Material

Once you've identified the correct message, consider the mounting location.

Self-Adhesive Vinyl Signs

Self-adhesive signs may be suitable for compatible smooth, clean surfaces such as electrical cupboard doors and equipment panels.

Rigid Plastic Signs

Rigid plastic signs may be suitable for walls, plant room entrances and other locations where a mounted board is required.

Outdoor Electrical Warning Signs

Outdoor installations may require durable materials and suitable fixings.

Check the individual product specification to ensure the selected sign is appropriate for the expected conditions.

What Size Should You Choose?

Consider:

• Viewing distance.

• Mounting position.

• Lighting.

• Available space.

• Whether wording needs to be read from further away.

There is no single sign size suitable for every electrical installation.

Are Danger Electricity & High Voltage Signs Required by UK Law?

Electrical safety in UK workplaces is governed by several legal requirements.

The Electricity at Work Regulations 1989 establish duties relating to electrical systems and work activities.

The Health and Safety (Safety Signs and Signals) Regulations 1996 require appropriate safety signs where significant risks remain after other relevant control measures have been taken.

Recognised safety sign symbols, including the electrical hazard warning symbol, are specified in BS EN ISO 7010.

However, displaying a Danger Electricity or High Voltage Sign does not automatically establish compliance.

Signs should support appropriate arrangements such as:

• Electrical risk assessment.

• Suitable equipment design and maintenance.

• Safe isolation procedures.

• Access controls.

• Competent electrical work.

• Safe systems of work.

• Appropriate training and supervision.

A warning sign is not a substitute for making an electrical installation safe.

Common Mistakes When Buying Electrical Warning Signs

Avoid these purchasing mistakes:

1. Using a High Voltage Sign on equipment that is not high voltage.

2. Assuming low-voltage equipment cannot be dangerous.

3. Choosing signs based only on their appearance.

4. Displaying a general warning where a more specific message is necessary.

5. Installing signs where they cannot be seen before the hazard.

6. Using signs instead of suitable access controls.

7. Choosing unsuitable materials for outdoor installations.

8. Selecting signs that are too small for the viewing distance.

9. Assuming a warning sign replaces safe electrical isolation.

10. Failing to review signs when equipment or installations change.

Danger Electricity vs High Voltage Signs: Buying Checklist

Before ordering, check the following.

Identify the Installation

• Electrical equipment or area identified.

• Operating voltage confirmed.

• Electrical hazards assessed.

• Access arrangements reviewed.

• Relevant safety requirements considered.

Select the Warning

• General electrical warning considered.

• High-voltage warning selected where appropriate.

• Additional access notices reviewed.

• Isolation or maintenance notices considered separately.

• Sign wording accurately reflects the hazard.

Choose the Product

• Suitable size selected.

• Appropriate material chosen.

• Mounting location identified.

• Viewing distance considered.

• Required quantity confirmed.

Installation & Maintenance

• Signs visible before approaching the hazard.

• Notices not obscured.

• Damaged signs replaced.

• Signage reviewed when installations change.

Frequently Asked Questions

What Is the Difference Between Danger Electricity and High Voltage Signs?

Danger Electricity Signs communicate a general electrical hazard. High Voltage Signs specifically warn about high-voltage equipment or installations.

Can I Use a High Voltage Sign on a Normal Electrical Cupboard?

Not automatically. If the cupboard does not contain high-voltage equipment, the wording may be inaccurate. A general Danger Electricity Sign may be more appropriate.

What Is the Electrical Hazard Warning Symbol?

The recognised symbol is a black lightning bolt inside a yellow warning triangle, identified as W012 in BS EN ISO 7010.

Are High Voltage Signs Legally Required?

Appropriate safety signs may be required where significant risks remain after other relevant controls. The correct signage depends on the installation and applicable requirements.

Is Low Voltage Electricity Dangerous?

Yes. Low-voltage electrical systems can cause serious or fatal injuries.

Where Should Danger Electricity Signs Be Displayed?

They may be appropriate on electrical cupboard doors, equipment enclosures, plant rooms and other relevant locations where electrical hazards need to be communicated.

Do Electrical Substations Need High Voltage Signs?

High-voltage substations will generally need suitable warnings and access controls. The exact signage should be determined by the installation and applicable requirements.

Can Danger Electricity Signs Be Used Outdoors?

Selected products may be suitable for outdoor use where the materials and fixings are appropriate for the environment.

What Size High Voltage Sign Should I Buy?

Choose a size appropriate for the viewing distance, mounting location and lighting conditions.

Buy Electrical Hazard Signs from The Sign Shed

Whether you're identifying an electrical cupboard, updating a switchgear room or replacing warning notices at a high-voltage installation, choosing the correct sign helps communicate electrical risks clearly.

At The Sign Shed, we supply a wide range of Electrical Hazard Signs for UK workplaces, commercial buildings, factories, warehouses and industrial premises.

Our collection includes:

• Danger Electricity Signs.

• High Voltage Warning Signs.

• Danger of Death Signs.

• Electric Shock Warning Signs.

• Electrical Cupboard Signs.

• Electrical Isolation Notices.

Choose from a selection of sizes and materials to suit different applications.

Made in Britain, with automatic bulk savings available on eligible orders.

Shop Electrical Hazard Signs at The Sign Shed and find suitable warnings for your workplace.