Gas safety in the workplace

Author : Simon Hopwood, Draeger Safety

02 November 2021

Gas safety is a topic that is rising up the agenda in many industries. Already a key priority area for the Health and Safety Executive (HSE), it is widely expected that regulations in relation to gas safety will come under increasing – and stricter – focus in the future, particularly with ever-increasing attention on environmental considerations and the introduction of new and lesser known fuels, such as hydrogen, driving awareness of the topic.

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Whilst critical to the safety of many businesses, gas safety is often part of a broad portfolio of safety issues. As a result, it can be a complex and challenging issue to address effectively. Furthermore, misconceptions and misunderstandings around the topic are common.

As we move ever closer to the use of greener fuels such as hydrogen, we face new challenges with gas safety. Some of hydrogen's properties require additional engineering controls to ensure its safe use. Specifically, hydrogen has a wide range of flammable concentrations in air (LEL4% - UEL 74%) and lower minimum ignition energy (0.019 mJ) than gasoline or natural gas (methane LEL 5% - UEL 14.3%), which means it can ignite more easily.

Ignition energy of flammable gases such as petrol, methane, ethane, propane, butane, and benzene is in the order of 0.1 mJ, (Ayumi Kumamoto et al 2011). To put this into perspective, a static shock that you can feel would be in the order of 1mJ!

Add to this that it’s colourless, odourless, tasteless, non-toxic and burns with a flame that is almost invisible to the naked eye, and it’s easy to see how the dangers of hydrogen could be underestimated.

Therefore, specific training on gas safety – particularly for gases distinctive in certain industries – is usually an invaluable way of helping to correct these types of misconceptions.

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Another key issue to be aware of is that different types of monitoring and detection devices are needed for different settings and applications. For example, a common mistake (or ‘work around’) is for portable personal gas monitoring devices to be used instead of a permanent point detector. Portable monitors are battery powered, which introduces an opportunity for human error if they are not sufficiently charged and they are therefore unsuitable for constant monitoring requirements. Additionally, their alarms are designed to be heard or seen when worn about the person, so are not sufficiently loud to warn someone on the other side of a room, or other large space. Most importantly they cannot warn an operative when an area is safe to enter (outside of that space) without having to enter the hazardous area in the first place. If we consider again hydrogen, that is 14 times lighter than air, will rapidly rise, and any collection of a gas cloud will be near the ceiling and thus well out of reach of any portable device.

Using fixed permanent gas detection removes the opportunity for human error, or risk taking in situations where, for example, a portable device may have run out of charge but due to operational or production pressures, the temptation might be to enter an area of risk anyway, on the assumption that it is only for a short time. There have been cases of this happening where carbon dioxide has been present (a largely odourless and colourless gas) and fatalities have occurred as a result.

There are also examples of short cuts being taken to save money. Consider, a meat-processing factory that uses carbon dioxide and nitrogen in the packaging process. Both gases pose serious risks at certain concentrations. Yet it is not unheard of for a business to rely on someone opening external doors to ventilate the area as a ‘solution’ to this type of critical safety issue. All too often because it is seen as cheaper than addressing the need to monitor potential gas accumulation properly.

While carbon dioxide appears to have little toxicological effect in low concentrations, the risk of not having a suitable gas detection system in place is that if there is a build-up of higher concentrations, there is a risk of employees experiencing increased respiratory rate, tachycardia, cardiac arrhythmias, and impaired consciousness. While concentrations above 10% may cause convulsions, coma and even death.

Viewed in this light, it is clear that the only proper solution in this instance is a suitably-designed fixed gas detection system that would alert staff to the potential build-up of harmful gasses, whilst automatically triggering mitigating actions such as pre-programmed ventilation.

Image: Draeger

Furthermore, installation of smart sensors on fixed safety monitoring equipment enables staff to be proactively alerted of safety issues and interact with other systems, as well as identifying maintenance and servicing schedules. While in working environments such as food and drink manufacturing, a gas detection system can be set up, to not only sound an alarm when the gas readings rise above a safe level, but also to link up to a ventilation system. This means that not only are workers alerted to unsafe gas levels, but automated ventilation is activated by the control system to mitigate any impact. An added benefit of this type of approach is that systems are more efficient; instead of ventilation fans running permanently, they can be automatically triggered to turn on only when required, based on the condition of the atmosphere, as reported by the gas detection system.

Research from the Draeger Safety at Work report recently showed that if organisations are to optimise innovation and to utilise new connected technology to truly enhance safety in the workplace, there needs to be a conscious and consistent move to access and analyse smart technology data, and to use the findings to implement change. Analysing data produced by gas monitoring and detection devices offers valuable insight that will allow for better, more informed decision-making, both in the short and long-term. This data can also be evaluated to serve as the basis for more effective risk assessments and health and safety policies.

Other factors to consider when selecting an appropriate gas detector is the range of concentration anticipated and whether the presence of other gases may affect readings or even damage the sensor.

Overall, a gas detection device should be easy to use and provide sophisticated functionality; particularly important when connecting it to other devices and control systems for management-level summary data and reporting.

It is also essential to build flexibility into gas safety planning to ensure it can adapt in future, whether to add additional devices, or to introduce new functionality to capitalise on innovations or developments in connected technology.

Simon Hopwood, Draeger Safety

As in many other aspects of business, it’s a case of not necessarily opting for what appears to be the most cost-effective solution on day one but planning for the future – whether corporate expansion or the introduction of new technology or fuel sources which may generate new gas safety risks.

About the author:

Simon Hopwood has spent over a decade working with Draeger Safety in the UK and specialises in supporting businesses with their gas safety requirements. His experience includes work with a diverse range of industries, from food packaging plants and breweries to science and technology firms.