Working in Confined Spaces

  • Health & Safety
a man working in a confined space
Peninsula Logo

Peninsula Group, HR and Health & Safety Experts

(Last updated )

In this guide, we'll discuss working in confined spaces, confined spaces regulations, and safe systems of work.

No workplace is without hazards and risks. Especially if your staff work in confined spaces regularly. If you must conduct work in one, you need to follow confined space regulations. Otherwise, your business could suffer severe consequences.

Failure to carry out a risk assessment - or follow other legal duties - could result in the serious injury of an employee. Consequently, your company might face legal proceedings, employment tribunal claims, and even business closure.

In this guide, we'll discuss working in confined spaces, confined spaces regulations, and safe systems of work.

What is a confined space?

A confined space is an area that's enclosed or largely enclosed. For the law to consider it a confined space, it must present a reasonably foreseeable risk to workers. Such as not having enough oxygen, exposure to hazardous substances, or a lack of fire safety.

A confined space could be something small and restrictive, such as sewers. Or, it might be an area with a large cubic metre capacity, such as a grain storage silo. Whilst both spaces differ in size, they each present certain risks.

What is the current legislation for working in confined spaces?

The Confined Spaces Regulations (1997) is the legislation that advises on working in a confined space. It highlights the key duties businesses must comply with when conducting this type of work.

The legislation states that employers must:

  • Avoid carrying out tasks in confined spaces. For example, avoid entry and commence work activity outside instead.
  • Conduct a risk assessment. This will highlight the present risks of the confined space, and any other dangers you should be aware of.
  • If entry is unavoidable, ensure work carried out follows safe systems. For instance, having ongoing communications with those working in confined spaces via radio.
  • Implement emergency arrangements in case of emergency situations. For example, appointing a person in charge of calling emergency services if an accident occurs.

Following the above will ensure any work you perform in confined spaces is done in a lawful, safe manner.

Do you have to be trained to work in confined spaces?

Yes, employees working in a confined space must undertake relevant training. This ensures they are able to perform the work safely.

Confined space training might:

  • Discuss what makes a confined space dangerous.
  • Detail what to consider when conducting risk assessments.
  • Raise awareness of workplace legal responsibilities.
  • Outline emergency procedures.

Employees working in a confined space should be a competent person, trained in both the work and use of emergency equipment.

What documents do you need to work in confined spaces?

If your risk assessment reveals that the confined space is high-risk - under UK law - you will need to carry out a permit-to-work. Permits-to-work is a documented procedure that sets out requirements for you to continue working safely.

It also authorises specific employees to carry out specific work in a specific time frame. This includes an outline of what work will be done, and how you plan to conduct it. It's essential in any high-risk work, because it provides a documented trail of the considerations you make in regard to hazards.

You cannot follow a generic document when writing permits-to-work, as they are designed for specific use only. Permits-to-work are highly-detailed to establish Health & Safety compliance. So ensure those performing them manage them carefully.

What are the specified risks of working in a confined space?

The Confined Spaces Regulations (1997) outline several specific risks of working in a confined space. You should ensure yourself and your employees are aware of them all. So you know how to mitigate or remove them.

Let's explore these specified risks in more detail.

Fire or explosions

Fire or explosions present significant risks when working in a confined space. This is typically because of a build up of liquids, gases and other substances. Similarly, using hot power tools or machinery increases fire risk because of the sparks they produce.

Loss of consciousness from increased body temperature

Another risk of working in a confined space is extreme heat because of inadequate ventilation. The use of heavy personal protective equipment (PPE) and construction work only worsens this. This can result in the collapse - or even heat stroke - of your employees.

Noxious fumes and reduced oxygen levels

Employees may also lose consciousness if exposed to dangerous substances and gases in excess. For example, noxious fumes such as ammonia or chlorine. This can pose a threat as gases flooding in can reduce oxygen levels. Consequently, workers might be unable to breathe properly.

Drowning from liquid level increase

Excess water is another specified risk of working in confined spaces. Due to the little to no drainage, enclosed spaces fill up with water quicker. Meaning, floods can occur rapidly and prevent workers from finding a safe exit. This could put workers in danger of drowning.


Asphyxiation is another risk associated with working in a confined space. A build up of dust, grain, or any other contaminant can mean workers struggle to breathe. Even if water gets into a closed compartment (causing rusting), it could result in a depletion of oxygen levels. Subsequently, staff may asphyxiate.

How to prevent injury whilst working in a confined space

Now you're aware of the risks a confined space can present, you should follow a safe system of work. This includes several factors, and each one is equally necessary to ensure compliance with Health & Safety laws.

We've outlined our brief guide to working in a confined space below:

Conduct risk assessments

The first step to take when working in confined spaces is to conduct a risk assessment. A risk assessment will help ensure safe entry into the enclosed space. Moreover, it will outline what hazards the enclosed space presents - and the risks these pose.

For example, performing one might reveal that the valves cannot be locked shut. Which means you run the risk of workers being exposed to hazardous substances.

For more guidance on how to conduct a risk assessment, visit the Health & Safety at Work Regulations website. Or, take a look at our guide.

Provide breathing apparatus

You should also ensure you provide your staff with appropriate personal protective equipment (PPE). This includes any breathing apparatus which will help employees breathe properly.

Protective gear might also include:

  • Gloves to avoid burns.
  • A helmet if operating in unsteady construction.
  • A face mask to increase oxygen levels.

The law requires you to provide PPE when undertaking high-risk work. And that any PPE you supply must be at the expense of your business.

Enforce training requirements

To prevent injury in confined spaces, you should lay out what training you expect from employees. Emphasise that it's a requirement and necessary to any work you perform in confined spaces.

You could ask employees to complete an online course, or bring in a competent person to provide the training. Either are lawful, but in-person training might be more effective, as employees can practice first hand.

Make emergency arrangements

You should also ensure you make emergency arrangements for employees when they work in a confined space.

This includes having a staff member trained in first aid. And having rescue equipment stored in a safe, nearby location, which you can easily access in case of emergency.

Get expert advice on working in confined spaces from Peninsula

Ensure you follow the approved code of practice when working in confined spaces. This includes providing PPE and training, assessing the risks of a confined space, and implementing safe systems.

This will ensure the Health & Safety of your employees, and prevent serious injury from occurring. If you don't manage to work in a confined space lawfully, you could risk legal trouble, hefty fines, and damage to your business's reputation.

Peninsula offers expert advice on working in confined spaces. Our teams provide 24/7 HR advice which is available 365 days a year. We take care of everything when you work with our HR experts.

Want to find out more? Contact us on 0800 028 2420 and book a free consultation with an HR consultant today.


Got a question? Check whether we’ve already answered it for you…

Related articles

  • person writing on note pad


    Health & Safety Audit

    In this guide, we'll discuss what a Health & Safety audit is, the benefits of conducting one, and the process to follow.

    Peninsula TeamPeninsula Team
    • Health & Safety
  • a woman on her phone holding her head on a couch


    Endometriosis at Work

    In this guide, we'll discuss the effects of endometriosis on your employees, how Peninsula can help you support them, and the legislation you must follow.

    Peninsula TeamPeninsula Team
    • Occupational Health
  • a woman in PPE working


    Health & Safety Software

    In this guide, we'll discuss Health & Safety software, its benefits, and how Peninsula can help with your workplace safety management.

    Peninsula Team Peninsula Team
    • Health & Safety
Back to resource hub

Try Brainbox for free today

When AI meets 40 years of Peninsula expertise... you get instant, expert answers to your HR and Health & Safety questions

Sign up to our newsletter

Get the latest news & tips that matter most to your business in our monthly newsletter.