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Confined Space Working

Published: 10th Apr 2014

I am the son of a Civil Engineer who worked in the drainage and sewerage sectors for more than 45 years, both in the UK and in the Middle East.

I am still amazed by my father’s ability, even though he’s now retired, to regale me with tales of his working life, and, whenever required, his ability to provide reasoned and invaluable advice on a variety of engineering topics, in keeping with whatever challenges my company’s portfolio of projects may throw up.

The point to my introduction you may ask? It’s simply this: despite his working life having started in the 1960s and the technological advances having been made in almost every area of our daily lives, the reality is that while technology may have evolved, we, as human beings, have regressed.

Safety schisms

From my growing up in Seventies’ UK, at a time when Darth Vader himself was ‘moonlighting’ as the Green Cross Code Man talking road safety, and being introduced to the ‘Clunk-Click, every trip’ mandatory seatbelt campaigns of the early Eighties, I have witnessed the deterioration of our basic hazard perception skills to such an extent that I believe we no longer see ourselves as accountable for our ‘lemming like’ behaviour.

This is demonstrated by the following examples:

1) If we were to scald ourselves with a hot coffee, we look first to the absence of hazard warnings on the coffee cup lid, rather than inwards, when apportioning blame for the event. Having seen boiling hot water being poured into a cup some 30 seconds before the spill, is it not reasonable to expect that it may well still be hot when putting it to our lips? Apparently not.

2) When driving, we no longer rely on the common sense approach of reducing speeds, or leaving greater gaps between ourselves and the car in front in poor weather. Instead we prefer to castigate Toyota or Ford for the fact that their vehicle, supplied with 47 airbags and ABS brakes, did not stop in 0.3mm when we were driving at 50 mph on black ice – and caused a collision. Clearly the collision had nothing to do with our driving ability or attitude.

While so far the tone of this article may appear to be somewhat tongue in cheek, when it comes to the topic of confined space working, and the perils of hazardous atmospheres, we haven’t advanced very far from the days of having canary birds in cages to alert miners to their impending doom.

With all the aforementioned technological advances now to hand, I find it extraordinary that in some developed and developing countries alike, our sole progress is to have stopped the use of these ‘sacrificial’ canaries, lest we incur the wrath of outraged animal rights groups. Incredibly, we’ve replaced them with – wait for it – human sacrifices.

I remarked earlier about tales told by my father of past escapades in the workplace, when Health and Safety was almost a ‘black art’. Having heard stories about construction related fatalities – specifically one instance of people being overcome by ‘sewer gases’ in the Sixties – I could appreciate that workplace fatalities in respect of confined spaces and sewers may have occurred through a lack of understanding of the workforce, a lack of available training, safe systems of work or PPE. To still have such deaths recorded today is nothing short of criminal.

Anticipating hazards

For the purposes of this article, using some ‘doom and gloom’ poetic license, I will briefly touch on elements of the ‘Confined Space Regulations 1997 (UK)‘, to identify how a lack of basic hazard and risk assessment practise, combined with a lack of employee training can lead to companies putting their employees unnecessarily at risk, with disastrous consequences.

Let’s consider a very simple trench, to be excavated manually in a sandy location, and fewer than two metres deep.

In accordance with the Confined Space Regulations we are required to mitigate specified risks that could be reasonably foreseen – namely, entrapment (engulfment) or asphyxiation by a free flowing solid, in this case, sand, caused by a trench collapse.

Our experience of basic excavation safety might suggest that we focus on the provision of basic benching, shoring or sloping of sides to prevent such a collapse. Add in an access ladder or two, some perimeter edge protection and we have the basis for presuming that the known hazards related to the work have been eliminated, or at least suitably mitigated.

If we were to then introduce an additional environmental factor into the scenario, that of a water table level of, say, 1.8m below ground, would we then think to consider the risk of drowning through increasing levels of liquids, or dismiss it as being improbable, given the level of the water table is known and constant? I venture that this risk would, typically, be dismissed, so we are still within the requirements of the regulations.

Some recent history

During the construction phase of a well known housing development in the United Arab Emirates, just such a trench was being dug. Workers had reported the presence of a strange smell down in the bottom of the trench to their foreman.

They had started to leave the trench when the foreman gave the instruction to continue their work, given that the smell had disappeared. One of the workers collapsed and the foreman then sent in others to help the casualty. None of them made it out of the trench alive.

When the police recovered the victims’ bodies and investigations had been completed, it transpired that while moving around in the bottom of the trench – containing approximately six inches of water – workers had systematically been agitating the water surface sufficiently to release large concentrations of water soluble, hydrogen sulphide gas.

Back to – human – canaries

It is a well documented fact that the majority of reported fatalities in relation to confined space working – both worldwide and throughout this region – result from the victims being exposed to, and subsequently being overcome by hazardous atmospheres.

This statistic is made even more poignant when you consider the fact that a lot of these victims had gone, or been sent into the spaces to rescue an incapacitated colleague.

Why, then, with all the historical data available, should this still be the case today, 50 years on from the instance, as told to me by my father?

Take the trench example, left. Had the foreman recognised, as his workers had done, that the nagging ‘rotten eggs’ smell was indicative of a safety issue, he would have stopped the work and sought advice. This ‘human’ gas detector, when conducting his own test, detected no such smell, however, and sent the workers back to work.

Had he understood the effect that H2S has on the body, specifically our sense of smell, he would have known that the smell having disappeared was in fact an even more dangerous state of affairs – and the fatalities could have been avoided.

As with all tasks, when it comes to health and safety at work, the ‘Six P’s Principle’ applies:

Proper Prior Planning Prevents Poor Performance.

This is never more relevant than when it is applied to confined space working.

Factors to consider

1) Design

While not working in the UK and beholden to its Construction Design and Management (CDM) regulations, I firmly believe that at source, the designers of modern structures and systems heavily influence the occupational health and wellbeing of construction and maintenance workers alike through their inherent ability to either introduce or reduce unnecessary risks in the workplace.

As developing countries strive to improve their respective legislative platforms, it is incumbent upon them to embrace the notion that the employer’s ‘Duty of Care’ should in fact commence at the design phase.

With the level of technology now available, such as CCTV systems for conducting surveys of pipes and vessels, all manner of sensor arrays and measuring devices and remote or surface controlled plant and equipment such as Micro Tunnel boring Machines (MTBMs), the ability to incorporate engineering solutions to ‘design out’ problems faced – such as mandatory man entry into confined spaces – has never been so easy.

2) Defining confined spaces

Following on from the actual design of structures and systems, the location of residual confined spaces potentially requiring man entry is of vital importance to the development of Safe Systems of Work (SSOW).

Typically, competent health and safety professionals can allude to a definition of confined spaces, similar to that found in the Confined Space Regulations 1997 (UK):

“Confined space means any place, including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk; where “specified risk” means a risk of:

• Serious injury to any person at work arising from a fire or explosion

• The loss of consciousness of any person at work arising from an increase in body temperature

• The loss of consciousness or asphyxiation of any person at work arising from gas, fume, vapour or the lack of oxygen

• The drowning of any person at work arising from an increase in the level of a liquid

• The asphyxiation of any person at work arising from a free flowing solid or the inability to reach a respirable environment due to entrapment by a free flowing solid where “free flowing solid” means any substance consisting of solid particles and which is of, or is capable of being in, a flowing or running consistency, and includes flour, grain, sugar, sand or other similar material“

Author’s note:

Throughout the Middle East region, the interpretation in the first place of what constitutes a confined space on any given project, site or facility may differ from person to person, organisation to organisation, or country to country.

These very basic discrepancies throughout the region can be traced back to a series of contributing factors, such as:

• A lack of clear legislative guidance

• A lack of management or client awareness/enforcement

• Education levels of the migrant workforce, both manual labour and supervision

• Qualification levels of employed HSE professionals

• Budgetary constraints for training or equipment investment

3) Location and basic environment

The location, configuration and construction of confined spaces – once defined as above – can have a significant impact on the constituents of the required SSOW, with factors to be considered including:

• Is the confined space indoors or outdoors?

• Is it above ground or underground?

• What is it constructed of?

• Is it a standalone space or does it form part of a larger installation?

• What is the space usually used for?

• How might access to the space be gained?

Asking such questions serves to provide a clear picture of some of the basic hazards and risks to be mitigated, before any of the more technically challenging hazards and risks can be considered.

Taking the questions above as logical starting points, an assessment as to the suitability or otherwise of your current team to complete the required task can be made. If your existing cadre of employees is not sufficiently skilled or equipped to undertake the work in the first place, the early recognition of the requirement for specialist consultancy support, training or subcontractors may prove to be a life saver.

4) Task

In order to move closer towards the development of the required SSOW, the task to be performed inside the confined space should be clearly defined and understood. Factors to consider here include:

• Is it a one off or repetitive task?

• Is the task to be completed by a single individual or will it be performed by a team?

• How long will the task take to complete?

• When will the task be completed?

• Does the task itself require specialised training if it were not to be completed in a confined space?

• Does the task involve ordinarily hazardous processes or substances?

5) Hazards and risk

Having broken down the basic elements of both the individual task and the makeup of the confined space where the task is to be performed, we can then start to analyse the hazards, both individually and collectively, to build up our complete risk assessment. You must take care to cross reference the definitions, as found in the applicable Confined Space Regulations, for the area of operations, and consider which ‘foreseeable specified risks’ may exist and be required to be mitigated.

6) Control measures

Safe Systems of Work for confined space working may include some or all of the following control measures, depending on the factors discerned earlier:

• Permit to Work Systems including the use of entry logs

• Provision of intrinsically safe electrical installations/equipment

• Prohibition of Hot Works activities

• Provision of forced air ventilation systems including purge ventilation

• Atmospheric testing – both pre-entry and constant while the work is ongoing

• Use of Breathing Apparatus

• Use of man-entry tripods and winches

• Buddy systems/restriction of lone working

• Communication systems

• Defined maximum confined space working times

• Specific training programmes including third party conducted courses

7) Training

Once we have identified the hazards, completed our risk assessment and started to build up a Safe System of Work to be used, we must then identify any specific training requirements to ensure that those workers associated with the task can perform it safely.

Basic subject task training aside, such as cleaning, cutting, welding, painting and the like, we also look to focus on the specifics of confined spaces – entry and rescue courses; Gas Detection and Authorised Gas Tester training; the use of Self-Contained Breathing Apparatus (SCBAs) or other breathing systems, as applicable; and advanced First Aid training.

When it comes to training in respect of confined space working, care must be taken to select appropriate attendees, including the actual workers required to complete the task, those requiring sufficient knowledge to supervise it, as well as health and safety staff.

A word of caution

Unfortunately, when it comes to atmospheric testing, a little knowledge can be a dangerous thing.

In consideration of atmospheric testing, you need first to understand what you are testing for and why. For example, the testing of oxygen levels only in an area that may have the potential for H2S presence, such as in sewers, would not reduce the risk to employees. Likewise, to test for methane presence when the task may involve the production of carbon monoxide fumes may be similarly futile.

When it comes to the selection of atmospheric testing systems themselves, again care must be taken, with due consideration required to be given to the following:

• Do they require a person’s physical presence in an area where contaminants may be present, to record values? If yes, they would not be suitable for pre-entry atmospheric testing purposes

• Are they designed for single use or continual monitoring purposes?

• If for single use, how many do you need?

• Do they require spare parts, maintenance, calibration or servicing?

• Do they monitor levels of a specific gas such as oxygen or do they monitor levels of multiple gases simultaneously?

• How long does it take to take a reading?

• Are they battery operated and require charging?

• What is their detection range?

• Are they fixed installations or portable?

• If a contaminant’s trigger level is reached, do they have audible alarms?

In summary, it is clear that confined space working is as potentially hazardous today as it was during my father’s working life, and yet, with the health and safety profession having swiftly evolved to the point where problems faced are far more easily overcome, for all the systems and technologies available, the one constant, when analysing failure points of SSOWs, is man.

To this end, I would urge you, the region’s health and safety professionals, to stand up and be heard, so that our colleagues don’t collapse and be counted. Long live the canary!

Published: 10th Apr 2014 in Health and Safety Middle East

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2 articles on HSME
Confined Space Working
By Matthew Cox