The lethal danger posed by enclosed spaces in the supply chain

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Tragedies can, and do, result from the obscure risks in confined and enclosed spaces across the container supply chain – and the carriage of dangerous chemicals, with associated toxic gases, naturally heightens these risks.

There are innumerable spaces found through the global supply chain that should be considered enclosed or confined, some more obvious than others. They include limited openings for entry and exit to/from a confined area, a space with inadequate ventilation and one not specifically designed for continuous worker occupancy.

Unfortunately, these spaces claim many lives each year when ill-prepared workers enter them, often for reasons that are never fully understood.

The key risk is that workers may not readily recognise spaces that could present danger. In the context of hazardous chemical transportation unitised cargo equipment, and in particular tank containers, form the main focus of these risks. Although there might well be a heightened awareness of danger by those involved in transporting these units as opposed to regular dry containers, incidents do unfortunately occur.

There are a variety of tanks used to transport cargo globally, including road tank trailers, tank railcars and (ISO) tank containers. Such cargo transport units (CTUs) are prime examples of a confined space risk in the supply chain.

Whilst the main lid of such tanks provides access and egress to the interior of the CTU, access is restricted, and there exists an inherent danger to workers who enter this space from oxygen concentration or the presence of toxic substances. The air we usually breathe contains 79% nitrogen and 21% oxygen. Once the oxygen content of the air decreases or increases, the associated risks change.

Oxygen-enriched atmospheres give rise to an increased risk of fire and explosion. An atmosphere with an increase of as little as 1% to 2% oxygen can be extremely hazardous. When compared with a fire in normal air, an oxygen-enriched fire will be more intense, will burn at higher temperatures and has a greater heat output rate. Where reduced oxygen content is concerned, judgement becomes impaired and, ultimately, life can no longer be supported, even if the remaining content of the atmosphere is harmless. Lack of oxygen is a silent killer.

Put simply, without sufficient oxygen the human body starts to shut down very quickly, with two primary implications being heart failure and brain damage. In the event of heart failure, the brain can survive for approximately six minutes, but after five minutes irreversible damage can be sustained. Any rescue operations are, therefore, time-critical and, even with an immediate deployment, the risk of serious injury or fatality is elevated.

The quick onset and catastrophic nature of these symptoms often leads to others rushing to the aid of the casualty, unaware of the reason for their collapse. Statistically, over 60% of fatalities connected to confined and enclosed spaces are suffered by those who observe the casualty without appreciating the cause and enter the space to attempt a rescue – people innately seeking to help.

Risk management

Assessing the need to work in any given confined space is a basic starting point – by asking the question: is entry essential? There are examples where work could be performed from the exterior. However, where a tank container is concerned, many tasks associated with cleaning and maintenance will render workers entering the confined space inside a tank unavoidable. In these cases, adequate precautions must be made, and the next step should be a risk assessment of the work to be undertaken by a competent person and thereafter a safe system of work should be developed and implemented, along with a permit to work.

This competent person should be appointed and tasked with ensuring that the risk assessment is adequately completed and that safe working practices are followed throughout. In addition, a competent “watcher” should be physically present throughout the work, providing an immediate response in case of emergency. The “watcher” should monitor each stage of the work undertaken to ensure compliance with the defined safe system of work.

Annex 8 of the ILO, IMO and UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code) focuses on the risk assessment process. This should have, as a minimum, the following elements: the task to be carried out; the working environment, materials and tools to be used; the training and competence of those undertaking the work; and, finally, arrangements for emergency response and rescue should it be required. In addition, access should only be allowed under a safe system or permit to work procedure and the supervision of a responsible person. A permit to work assists in ensuring that a formal check is undertaken, confirming that all elements of the safe system of work are in place ahead of a worker being allowed to enter the confined space.

While not exhaustive, TT offers the following risk mitigation strategies, applicable to both tank container operations and most other enclosed space situations within the global supply chain:

• Always assume that confined spaces are unsafe
• Create awareness of the risks and continually invest in staff training
• Procedures need to be robust but not overly burdensome or complex, in order to impede a tendency for short cuts
• Embody a culture where time and resource are fully aligned to safety, regardless how minor the immediate task
• If entry is unavoidable, undertake a risk assessment to ensure that there is a safe system of work
• Where possible, ventilate the area before entry. Use breathing apparatus if the air inside the space cannot be made fit to breathe
• Test the air before entry; monitor it and the workers during the procedure, deploying a watcher who is physically present
• Ensure that people inside the space can communicate with those outside
• Restrict access to authorised personnel by, for example implementing a permit system
• Ensure that the workers selected are competent and physically able to do the task
• Perform emergency rescue drills, providing practice in the process of safely removing an injured or unconscious person

These basic suggestions have either no, or very little, cost implication and can save lives, keeping a company’s greatest asset, their people, safe.

Further information and advice can be accessed via the TT Club’s website, where these advisory documents can be downloaded free of charge: StopLoss: confined spaces (ttclub.com) and StopLoss: tank containers (ttclub.com)

This post is by Mike Yarwood, managing director, loss prevention at freight insurance specialist TT Club