How Often Do You Need Confined Space Training?

General Safety By Matthew Coombes

What is a confined space?

A confined space is any place that is enclosed by nature – though this does not always mean it is entirely closed. This can include a sewer pipe, a well, a chamber/tank/silo, pits or trenches. It may also include a small room or other enclosed areas which are small.

Confined space legislation states that working in confined spaces should be avoided where possible, by working from outside the confined space. This is similar to the stance on working at height, where it is preferable to work from underneath a roof instead of on top of it.

Where working in confined spaces can’t be avoided, the additional risks need to be identified, assessed and precautions need to be taken. Some of the most common risks are highlighted below.

Limited Oxygen Environment

When working in a confined space, there can often be a limited supply of oxygen which presents an increased risk of loss of consciousness and asphyxiation or drowning.

Many confined spaces will also be below ground level, or have components that are low-level. Invisible, odourless gasses which are denser than air such as carbon dioxide and carbon monoxide can be found in below ground spaces and low-lying components. These gasses can easily render a person unconscious or asphyxiate them if they are unaware of the presence of the gas.

Inhaling carbon dioxide/carbon monoxide can lead to light-headedness and confusion which makes it harder to think clearly and look to escape the space. Movement may also be limited making it not possible to egress quickly or easily.

Many fatalities related to working in confined spaces are as a result of asphyxiation and fatalities frequently occur when an individual is attempting to rescue someone who is in a confined space.


Chemicals that readily release vapours into the air, such as flammable gasses, solvents and chemical reactions can reduce the breathable air content of a confined space. This short video by the Construction Industry Training Board (CITB) highlights an example of a confined space which you may not expect, a domestic bathroom.

Even mixing household cleaning products such as bleach and ammonia can create deadly gasses that can render you unconscious in a confined space and lead to death.

In addition to this, the prior contents of the confined space or location in relation to services and flammable materials may mean that the space contains enough flammable materials that it has an explosive atmosphere. A welder repairing a slurry silo could ignite leftover methane, or non-intrinsically safe electrical equipment can create a spark. There may also need to be considerations for static energy which can create a sufficient spark to cause a fire.

What does confined space training involve?

Depending on the risks associated with the confined spaces in which you will be working, there will be a different requirement for training. Generally, the higher the risk, the more in-depth the training that you will need in order to work safely, or manage work safely.

Typically, confined space training will include:

  • An understanding of legislation.
  • Understanding the risks that confined spaces involve.
  • Preparing to enter and managing work safety in confined spaces.
  • Entering and exiting confined spaces.
  • Preparing and using respiratory protective equipment (RPE) for working and escape purposes.
  • Using equipment and tools safety.
  • Dealing with emergencies.

There may be additional or specific course requirements for low, medium and high-risk training in addition to this.

How often do you need confined space training?

The purpose of training is to develop competency and understanding around a topic, in this case to protect workers from a specific risk. You should get refresher training if you feel that your understanding or competency around the topic has reduced.

As well as this, many training courses will have a limited duration for certification.
CITB Confined Spaces training needs to be refreshed every three years.

City & Guilds Level 2, Level 3 and Level 5 Confined Space training is typically refreshed every three years.

Other specific training you may need to work in a confined space

Personal Protective Equipment (PPE) & Respiratory Protective Equipment (RPE)

Depending on the risks present there may be additional equipment involved in the work which would need its own specific training. A good example of this is that different RPE fits different individuals, so they will need to understand how to properly equip, use and unequip the equipment that suits their face.

Lock-off, Services and Equipment

Locking off services such as steam, electricity and water to prevent them from entering or interacting with the confined space is essential in many circumstances. You don’t want water or steam entering a confined space when a person is inside it, and electrical current freely flowing through a confined space can electrocute those in contact with it.
The same applies for locking off equipment that may be in the confined space such as mixers and fans.

Staff involved in the confined space activities and staff present on the site will need to have an understanding of lock-off procedures to ensure that they do not activate attached services or equipment while persons are within the confined space.

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