OSA Magazine Logo
City Technology

Safe System Selection

Published: 27th Nov 2013 in OSA Magazine

Detecting safety in confined spaces

Mistakes in the workplace happen – fact. Most people use mistakes made as a learning tool, a reference point to look at an alternative when undertaking the same task next time. When working within confined space’s, however, mistakes made could ultimately mean loss of life, so learning to work safely in these potentially treacherous environments needs to be done prior to entering them to reduce or eliminate the potential for mistakes.

Appropriate safety instruction along with knowledge in the use of relevant equipment is essential to all operatives intending to work within confined spaces. Here are my five steps to working safely within confined spaces.

Step one – legislation

Firstly, understanding what appropriate legislation and guidelines are in place is paramount. The UK HSE regulations define confined space works as “Any place in which by virtue of its enclosed nature there arises a specified risk of harm from fire or explosion; loss of consciousness from increase in body temperature; loss of consciousness or asphyxiation from gas, vapour or lack of oxygen; drowning or asphyxiation from free slowing solids.”

Additionally, UK regulation also surmises that “Confined space entry should be avoided if an alternative means of achieving work can be completed. However, if entry is unavoidable, then a safe system of work should be followed. No person shall enter or carry out work in a confined space without sufficient arrangements for the rescue of persons in the event of an emergency.

Also, where there is a likely consequence of a relevant risk, the provision of rescue and resuscitation equipment must be provided.”

While lengthy and in depth, these pieces of law are in place as a result of previous lessons learned and as with any workplace where there are recognised national guidelines, failure to adhere to them leaves little ground to state a case of safe working practise.

Many mistakes within confined spaces are as a result of appointed persons or safety managers simply not understanding the nationally accepted recommendations when working in them. Taking the time to not only read, but understand these guidelines and how they impact on your confined space work is the first step to working safely.

Step two – training

Appropriate workplace training on the safety and hazards associated with confined spaces should be mandatory for all operatives working in them. Generally, UK confined space training will include instruction on applicable legislation along with practical and theory based learning on the safety products currently available.

These include – to various levels of ability – safe and appropriate use of harnesses, escape breathing apparatus, long duration breathing sets, gas detection units and other related PPE. Operatives should know and understand best practises to reduce risk of exposure to harm. All too often, familiarity with a working environment combined with a false sense of safety can lead to operatives becoming complacent and disregarding the potential hazards around them.

Within this training, instruction on using all your senses combined with a greater understanding of gas monitoring units is essential. Portable multi-gas monitors are readily available as relatively inexpensive, small and un-obstructive devices to alert the operative to gas, fume and vapour changes within the environment. Operatives should be taught how a gas monitor works including unit function test, how a gas unit will detect lower and upper explosive levels (LEL and UEL), short term and long term exposure limits (STEL and LTEL) and perhaps most importantly, identification of a faulty unit.

Proper instruction on the appropriate uses of breathing apparatus should also be achieved.

With various types of breathing apparatus available, understanding appropriate selection comparative to the working environment is important. In some circumstances, negative pressure filtered apparatus may be better suited than, say, long duration self contained breathing apparatus. It is knowing the differences in appropriate uses that will determine the safety of operatives working within confined spaces.

As with all training, while there is legislative guidance in place on when to undertake this instruction, regular updates in training should also be considered. It may well be that the individuals tasked and trained to work in confined spaces may not regularly undertake this type of work. That being the case, and as with any skills, they are forgotten as quickly as they are learned when not regularly used.

Step three – safety checks

Conduct a pre-entry check on equipment and the confined space environment prior to entry.

All too often, operatives are entering these environments without having achieved any pre-testing of either the equipment they intend to use to safeguard them while inside the confined space, or the initial status of the space they intend to enter.

Examination of safety equipment including harnesses, escape breathing apparatus and portable gas monitoring units should be achieved if for no other reason than the operative’s piece of mind. As a minimum, the key items to be examined should include an individual’s harnesses, any and all breathing apparatus to be used along with any gas monitoring equipment.

The industry standard when working temporarily in confined spaces is to use an ATEX rated portable four gas monitor. These units are configured with a CH4 flammable sensor, O2 Oxygen sensor, H2S Hydrogen Sulphide sensor and CO Carbon Monoxide sensor.

Configured to detect across this range of gases, the unit is set to alert the user by way of visual, audible and in some cases vibratory alarms when detecting a gas outside of accepted parameters.

Manufacturing and legislative guidance requires that these units are calibrated by an approved centre on a six monthly basis.

Additionally, guidance also recommends that a gas monitor function test should occur prior to every confined space entry.

When a gas detector sensor fails it can be unsafe for the user as they often have no way of knowing that the unit is faulty and not detecting all gas types. The visual display may well continue to show a zero reading without informing the user of the defect by way of an alarm.

In the absence of knowing, the operative would wrongly assume that all gas levels within the confined space were normal, and therefore potentially continue working within a hazardous environment.

This function test, or ‘bump’ test as it is known in the industry, should be taught to all operatives working within confined spaces. It involves a small canister which holds sufficient quantities of gas to trigger the gas monitor alarm. The gas is passed across the gas monitor sensors via a hose from the canister which then sets the gas monitor into alarm. This then assures the operative that the unit is fully functioning, or not, prior to any confined space entry.

Another common error when using portable gas monitors is made when the unit is switched on. Gas monitoring units will achieve a self test when initially switched on and take the ambient air around it as a baseline. As such, they should be activated outside of any confined spaces within a normal ambient air setting, rather than in a confined space, to ensure an accurate ‘zeroing’ of all sensors. As with all professions, knowledge of the tools and equipment to achieve any work safely is essential.

Step four – planning

Implement all identified safety equipment and follow the working method statement. When working within confined spaces it is important to follow all pre-agreed processes and methods for safe work. Ensure all equipment is in place and more importantly, where it needs to be in place. Use of escape breathing apparatus, for example, is of absolutely no use if it is outside the reach of the operative when required. 

Additionally, appropriate usage of portable gas monitors within a confined space need consideration. Will it be used in a passive setting where it is placed within the confined space in the same location during works? If so, it needs to be placed where it can detect likely gases such as identified plant, around hot works or ingress points, for example.

Alternatively, will the gas monitor be used in an active use capacity? This is where the operative will wear the gas monitor on his/her person throughout the confined space works.

This should be favoured over passive use when operatives are traversing away from the access/egress point. It is generally of more benefit to the operatives to wear a gas monitor about their person as ultimately any disturbed gases during movement would generate a quicker response from the unit than if it were in a temporary, fixed position. Additionally, some gases are lighter or heavier than air, so regular movement with the operative around a confined space is far more likely to initiate an alarmed response from the unit.

All this and more should be decided prior to commencement of work within a confined space and listed within the method statement. Any deviation to the planned safe process of work due to unforeseen circumstances should be discussed, where it may be decided to temporarily stop activities and rewrite a new method statement. At no point should any change in the safe system of work take place where operatives work outside the agreed process. Should this happen, any consequential incidents may not be adequately planned for, which may result in personal individual harm. Plan the work then work to the plan.

Step five – in case of emergency

Emergency arrangements when working within confined spaces need to be in place. With any planned confined space works, an attendant or stand-by person should be appointed to monitor all activities in and around the working environment. This individual should be trained to implement the predetermined rescue plan in the event of a confined space incident. 

If something can go wrong in the workplace, it should be planned for with appropriate measures in place to meet it. The workplace method statement should detail all identified hazards pertaining to the work being undertaken. On that basis, confined space works should include relative rescue and recovery equipment along with a pre-approved emergency action plan where all operatives are aware of the process to follow if things go wrong.

All too much focus is given to the work being undertaken without enough emphasis on achieving a response should things go wrong. An example of this was a recent telephone call we received from a company that was undertaking a confined space task that they had done numerous times before. During this task, however, a previously unidentified gas combined with hot-works within the space and created an ignition, causing a reported ‘minor’ explosion.

Fortunately, nobody was harmed but post incident, a review of equipment and processes in place to accommodate this type of incident found them woefully short of current best practises. This is not an isolated case, and no doubt the world over emergency response plans to confined space works vary enormously, depending on individual task-based knowledge and general attitude to risk.

Through correctly identifying the workplace hazards prior to commencement of works, selecting the appropriate risk controls, planning for the severity of actual harm and implementing sufficient emergency response, workplace incidents should be significantly reduced, and therefore so too will the potential for a fatal outcome. Appropriate consideration towards worst case scenarios during confined space works will also enable the site operatives to better respond to the potential emergency situations.


Confined spaces continue to be among the most hazardous environments to work in, and many mistakes by companies and individuals working within them have been made the world over. These mistakes have been highlighted, acted upon and in many circumstances subsequent penalties or prosecutions have followed. Unfortunately, it is inevitable that further mistakes will happen and more lives will be impaired or lost as a result of not following an appropriate safe system of work during confined space activities.

Employers need to ensure that a safe system of work is created proportionate to the risks of exposure, that appropriate safety equipment is acquired and in place, and perhaps most importantly, that all operatives involved in the task are aware of this safe process and work within it at all times. Safety equipment is readily available to assist when working within confined spaces and combined with appropriate training and identification of associated workplace hazards, operatives should be able to achieve work in these potentially life threatening environments without any undue harm coming to them.

Published: 27th Nov 2013 in OSA Magazine


Gary Watts

Gary Watts is part owner and operations director of Meditech Global, a medical, rescue and training services company based in the United Kingdom. His interest in safety equipment started in 2001 while in the employment of a national equipment distributor, just as safety equipment was becoming more accessible throughout the industrial sector. For more than 12 years Gary has been and continues to be taught by manufacturers in an array of safety and rescue based equipment, including breathing apparatus and rope rescue systems. As a certified breathing apparatus instructor, Watts actively teaches operatives working in confined spaces nationally.

In 2007, Watts trained as an emergency medical technician and has undergone various additional training since to enhance this status. Actively utilising his medical training within motorsport locations, Watts has first hand experience of dealing with trauma related injuries within a prehospital setting. Combined with his safety and rescue equipment knowledge and his emergency medical technician status, he has supported technically difficult onsite operations with the ability to offer an all-round immediate response where required.

In 2009 Watts achieved instructor status and has since been teaching and assessing within industrial locations on subjects such as confined space and height safety, along with prehospital medical training. Watts founded the company in 2011 and since this time a growing list of customers have procured Meditech Global’s medical, rescue and training services.

About Meditech Global

Through onsite operational support, Meditech Global offers emergency services trained and equipped personnel to safeguard workforces in technically challenging environments. Meditech Global’s rescue services continue to be utilised by four of the top 20 construction companies in the United Kingdom during technically challenging operations. Various gas and nuclear power stations also procure Meditech Global’s services during outage works, along with numerous highways agency contractors looking to enhance operational safety during inspection and maintenance works. In recent years this has included water rescue, where trained medical and rescue operatives safeguard customer workforces working on or around water.

As a registered Care Quality Commission (CQC) provider, Meditech Global also delivers professional, vetted and approved prehospital services during all its activities. These medical services are currently utilised by UK motorsport venues including Rockingham Motor Speedway and Silverstone Circuit. A range of accredited industrial and medical based training courses completes Meditech Global’s current services. 

Meditech Global’s staffing includes fire fighters, rope rescue technicians, paramedics, emergency medical technicians and water rescue operatives. This level of staffing ensures that whatever the operational demands, each undertaking is supported with the appropriate skill sets.

Gary Watts



+44 1536 206010

+44 1536 206010

Contact Us Events List Terms and Conditions Privacy Policy Sitemap Maintenance