No other area in safety attracts as much attention as confined spaces.
There is a range of specialised equipment, regulations and standards directly aimed at confined spaces. In addition there are specialised modules for safe work in and classification of confined spaces so clearly it is one of the most highly focussed areas of occupational safety. The question becomes why there is so much attention and is it justified? And what about the cost?
The why is simple: confined spaces are just not good work places to be in. By definition they are not designed for ease of entry or with workers in mind. Typically, they are visited infrequently and little is confidentially known about the conditions inside them or the consequences of undertaking work in them. This leads to several safety risks and strong mitigating strategies are required if we are to truly protect workers from risk. Even so, history shows unforseen accidents still occur (see Appendix 1). So what are the risks?
Primary of these is atmospheric risk: nentilation in confined spaces is typically poor. It pays to remember that these are not designed for human occupation. Most the time, a confined space is devoid of occupation and serves to contain equipment or capture overflows such as sumps rather than serve as a workplace. Ventilation is not only something not present but in some cases is actually counterproductive to the normal function of the confined space. Unfortunately what is good for equipment is not always good for workers. It seems obvious but in the first instance humans need clean breathable air not only to work but to survive. This is the major safety risk of confined spaces.
Historically, statistics indicate accidents occurring in confined spaces have been more frequent and often more serious than accidents in other workplace environments. This is driven by the fact that when things go wrong in a confined space it is difficult to rapidly respond, and an already compromised work area becomes even more compromised. These same statistics show the most common source of injury relates either directly or indirectly to respiratory issues from toxic gases, depleted oxygen, and, less frequently but of greater severity - explosions from combustible gases.
Putting it bluntly, workers need clean safe air and without it we compromise their safety. No one should go to work and become exposed to unnecessary risk; knowing confined spaces hold considerable risk, it should become incumbent on managers to mitigate these known and historically evident risks.
Of course it goes without question that we should first seek to design plants where confined spaces do not exist. Engineering away the risk is always, and should always be the first action taken. This is not always practicable so we need to consider how to mitigate the risk.
In order to mitigate we need to know a few things:
- What is likely to be the major source of risk? Air or the quality of air is always high in this list.
- How do we confirm whether the risk actually exists i.e. assessment. This will always include at least a visual inspection before entry and an air survey.
- If a risk exists, how severe is it and how do I mitigate it for example can I supply fresh air from outside?
- Change? Is something likely to change whilst a worker is in the confined space that increases risk either as a consequence of doing the work or from external activity for example welding in a confined space can reduce oxygen and generate carbon monoxide, painting in a confined space can release toxins or a sudden rainstorm can inundate sumps and drains.
- Escape? In the worse case scenario, how do we recover our colleague quickly and safely to improve their personal outcome?
Those of us fortunate enough to not have to work in these circumstances have a duty to consider and plan for our colleagues that do work in such environments of potentially high risk.
Of course we are all under pressure to look at costs. Preparing to work in a confined space is more expensive than working in other areas. It is a high risk environment by design and we know historically failure to plan and properly resource has consequences for our colleagues. We need to understand costs and ensure our plans to reduce costs do not compromise on safety. The problem is you may never know the consequences of a decision until it is too late.
Cost is a complex area and needs a good deal of attention. Cost is often related to purchase price, however in reality this is not always a good indicator of performance particularly when related to risk. Safety expenditure is related to mitigating risk (and consequently injury) to workers.
A good example of this is demonstrated by a reported circumstance observed in the shipping industry a few years ago in relation to gas detection where an extreme situation did occur. In this case, a small foreign low cost cargo ship entered local port. As is required before any offloading of cargo can occur an inspection is required to confirm the safety of the operations.
During this inspection it became obvious that the only source of determining the atmosphere was safe available on board were two budgerigars. When questioned the Captain confirmed these were indeed used to confirm the atmosphere as safe. Budgerigars were used as they were cheaper than canaries and they had two as a safety mechanism in case one died. It seems humorous but it really did happen. This is not normal practice and the modern shipping industry is one of the strongest supporters of safety but it does make us wonder what cost savings drove such a decision. Fortunately for workers the atmosphere was not compromised and so no negative consequence occurred from this poor practice.
The real challenges for safety professionals is we are funding circumstances we hope never occur. This makes it really hard to demonstrate in the normal profit/loss circumstance the value of safety expenditure. The argument goes as follows "We have not had any incidents or accidents with existing systems and practice therefore we do not have a risk". The consequences of this can be a reduction in focus or reduction in safety expenditure. This, from a business sense, comes directly off costs and improves the bottom line. What needs to be understood is a lack of incidents do not reflect risk rather either and hopefully good management or in some cases risk. Safety devices are not in place to operate every day rather to operate on that one really bad day!!
Safety expenditure is always in focus for positive and negative reasons so we really need to understand how it relates to risk. Gas detection is a classic example of this.
Gas detection has a high profile in confined spaces. This is driven by the historical observation that the majority of injuries in confined spaces have been respiratory related. Gas detectors aim to provide a profile of the breathability of the atmosphere before entry and during work within a confined space. These are critical devices providing warnings to take action to mitigate a respiratory risk. This is achieved by either not entering initially or if in the confined space, donning respiratory protective equipment or escaping. The question becomes if the atmosphere is the risk why not just wear protective devices?
Respiratory protective equipment is useful in confined spaces but often not practicable due to space and work requirements. Hoses and restricted entry means adoption of fresh air supply equipment (known as Supplied Air Respirators) can in itself present risks and planning must account for an escape means should air supply fail. Filters (known as Air Purifying Respirators) can only be used for a limited number and concentrations of toxins so are restricted in function and a gas detector is needed to establish concentration. All these have costs and training needed, cannot work with bearded employee’s (due to leak) and do not protect from explosion due to ignition of combustible gases and vapours. Respiratory protection is an important part of the story but not the solution.
When it comes to gas detection we want two basic things
- We need to know accurately what’s there and how much (concentration) and
- We need to know it fast (speed of response).
The "what’s there" and "how much" determines whether it’s safe to enter to do the work breathing or if some alternate strategy is needed the air present so accuracy is of utmost importance. If heating or potential sparking from the work is possible then also there is explosion risk.
The "how fast" is critical to responding to changes that arise in the confined space during work. This is arguably extremely critical as workers are already at high risk and will face potential difficulty in escaping. This is demonstrated in Appendix 2 which relates to a reported incident in mining directly attributed to slow responding gas detection. It is well worth considering in that whilst not a confined space in the classical industrial definition the slow speed of response of a gas detector still compromised the safety of the workers involved and they did not have to deal with restricted means of escape.
Earlier we spoke of the cost of safety with gas detection as a classic example of challenged expenditure so how does this relate to compromised safety?
A Compromised System
Gas detection function could be considered a level one area of focus in the hierarchy of safety for worker safety in confined spaces. Often it is solely based of a gas detectors reading that either entry is permitted or work undertaken. If that detector fails to respond accurately then either worker safety is potentially compromised or the job could be delayed. If we consider the two established areas on concern earlier mentioned
- We need to know accurately what’s there and how much (concentration) and
- We need to know it fast (speed of response).
How do we verify this?
We need to know accurately what’s there and how much (concentration).
Manufacturers and various codes, standards and regulations are clear on this. Validate the gas detector function and accuracy before use. A detector must be capable of detecting gas and doing so accurately. Since no one can truly know what conditions exist when using a gas detector or how the gas detector may have previously been exposed too no one can accurately predict whether a gas detector will work accurately each time. Even in storage gas detectors will change in performance so test before use each and every time is necessary. Doing less could compromise either the safety of the worker because the warning system is compromised or the job may not proceed due to over reading. Either way the job is compromised.
Here’s a thought? Ever sent a gas detector for service to be told the sensor is either faulty or not working? How long has it been faulty? What made it fail and what risk was placed on the worker and the company? History is littered by those who did not take gas detection seriously enough to spend the money on checking the detector with dire consequences. It’s like buying a car without brakes or hooking up a fall arrest harness to an untested unrated anchor. You just wouldn’t do it.
We all know of ill informed people or bravado of people not using gas detectors and ending up with serious injuries or death. It they do that at least it was their choice (which we should do all we can to stop) but to give them a tool and compromise it without testing completely is unforgivable. You wouldn’t give them a car to drive without brakes (or brake warning lights).
The real cost comes from the ability of the gas detector to continue to work after use in the work environment. The cost of testing is small if done correctly. MSA have dramatically reduced the amount of test gas used with low flow regulators, and testing technology to dramatically reduce the time taken (and cost) of testing. Even so some companies still report claims that testing is not necessary normally by those not taking the risk.
What really costs is when sensors or gas detectors fail through what could be considered normal use. The cost of these can be enormous and is not often disclosed when the product is presented. Confined spaces are confined work environments and yet few manufacturers provide integrated armour, shock protection and waterproofed designs as standard (if at all) like the MSA Altair series. Altair series detectors carry up to 5 years warranty on sensors and housing in normal use environments like confined spaces. The cost savings are made up front on long term reliability and availability by selecting a robust product rather than compromising safety by not testing.
We need to know it fast (speed of response)
When things go wrong you want to know fast. The typical performance standards allow up to 30 seconds and as long as 1 minute for certain sensors to respond to 90% of the gas environment. Just try holding your breath for 1 minute and then try get out a tight manhole of find an air supply. So why do sensors take so long to respond?
In simple terms standard sensor technology that exists in most gas detectors used today was not capable of responding quicker so to establish a standard that could not be met did not make sense. MSA Xcell sensors have changed all that and will challenge out held beliefs on sensor response time. Using new design technology and new proprietary electrochemistry these sensors have response times of up to 4 times faster than industry average along with significant extended in use life.
Even so the Australian and New Zealand standard for oxygen and toxic sensor performance (AS/NZS 4641) is largely voluntary except in NSW coal mines regulations so few actually test to it. MSA Xcells and Altair X series have met these requirements.
The take home message.
Don’t look to save costs by compromising response time and robustness in the purchase price. Look at the long term cost of performance reliability and safety risk. A good detector is one that works every time.
Never assume the detector is working correctly and reading gas. Blowing on it does not test all sensors for accuracy and speed and only a gas test as indicated by various standards will validate this. It is a cost saving that isn’t worth the risk.