ATEX Ventilation & Your Confined Space Project
Confined Space Safety Starts With The Right ATEX Ventilation: Here’s Why
If you’re a professional working in a heavy industry sector, you’ll know that unsafe conditions for confined space working can have fatal consequences. You’ll probably also be aware that proper ATEX ventilation is, therefore, of lifesaving importance for operatives on-site.
But what are all the dangers involved in confined working? Why is ATEX certified equipment so important? And what does a high-performance ventilation system you can rely on look like?
Keep reading to discover quick read answers to essential confined space working and ATEX ventilation questions PLUS equipment recommendations from our experts…
Confined Spaces + ATEX Ventilation: 1, The ‘Double Risk’
The UK’s Health and Safety Executive introduces the concept of a confined space by describing these working areas as “both enclosed, or largely enclosed, and which also has a reasonably foreseeable risk to workers of fire, explosion, loss of consciousness, asphyxiation or drowning”.
To break this down into a practical, three-step definition:
• 1, Limited openings for entry and exit
• 2, Unfavourable natural ventilation
• 3, Not designed for continuous worker occupation
Examples of confined spaces include storage tanks, silos, enclosed drains, sewers, boilers, void spaces and cargo, ballast, and oil tanks.
How dangerous can these areas be? A US Department of Labor OSHA case study warns that a 16.5ft deep manhole and scene of a sadly fatal workplace incident was found in one reading to have as little as 12.5% to 14.1% oxygen and 16,845 to 23,968 PPM CO2. An oxygen-deficient atmosphere has less than 19.5% available oxygen. Any atmosphere with less than 20.8% oxygen should not be entered.
Despite this an employee who had been working alone carrying out grouting was found unconscious at the bottom of the manhole, a space with a 4ft wide internal diameter and 2ft opening built on limestone chat.
The employer did not have a confined space entry policy.
The lack of oxygen behind many serious confined space incidents can occur in a number ways, such as a reaction between some soils and oxygen in the atmosphere, reaction between groundwater on chalk and limestone (causing carbon dioxide to displace normal air), cargo reacting with oxygen and more, rust forming in tanks and more.
These risks can:
• Build-up in sewers and manholes and in pits connected to the system.
• Enter tanks or vessels from connecting pipes
• Leak into trenches and pits in contaminated land, such as old refuse tips and old gas works
In addition to a risk to the initial operative working in the area, a ‘double risk’ aspect of confined space working makes these areas especially dangerous: fatalities often occur to not just the people injured during confined space working but also to those who try to rescue them without proper training and equipment.
However, oxygen deficiency is just one of the risks during confined space working! Read on for an overview of the essential dangers.
Confined Spaces + ATEX Ventilation: 2, More Hazardous Atmospheres
Two more potentially fatal hazards also pose a serious risk to operatives working in confined space areas.
• 1, Flammable atmospheres
• 2, Toxic atmospheres
In the case of flammable atmospheres, in the case of working in a heavy industry sector the presence of flammable gas, vapour or dust in the proper mixture is a particularly pressing risk.
It’s simple: Different gases have different flammable ranges. If a source of ignition is introduced into a confined space containing a flammable atmosphere, an explosion will result.
For example, this UK HSE case study reminds us that two employees were burnt whilst removing paint in a confined space within a yacht. The cause of ignition? An electric sander.
No risk assessment for entry to a confined space had been carried out and work equipment hadn’t been selected based on risk in a confined space.
Similarly, toxic atmospheres can be an immediate threat to life but can occur in a number of different ways.
• 1, The product stored in the space: In these cases, the product can be absorbed into the structure and / or tank coating and give off toxic gases when removed. Or when cleaning out the residue of a stored product, toxic gases can be given off.
• 2, The work being performed in a confined space: Toxic atmospheres are generated in various processes. For example, cleaning solvents are used in many industries for cleaning/degreasing. The vapours from those solvents are very toxic in a confined space.
• 3, Areas adjacent to the confined space: Meaning toxicants produced by work in the area of the confined spaces can enter and accumulate in a confined space.
In one incident, highlighted as a case study by the US Centers for Disease Control and Prevention, two labourers – who were brothers – tragically died while cleaning the drainage system of a California organic waste recycling facility: “The brothers were part of a three-man crew that was flushing out
the drainage system consisting of 24-inch diameter underground pipes accessed by approximately 14 manhole shafts.
“While using a high-pressure water hose to flush residual compost, the 16-year-old was overcome by hydrogen sulphide and fell to the bottom of a 10-foot shaft. The 22-year-old collapsed at the bottom of the shaft after attempting to rescue his brother.”
The case study notes that “contributing factors identified in this investigation
were the high concentration of hydrogen sulphide in the shaft, failure to implement a confined space and hazard communication program, and the age of the youngest victim”.
The common theme of poor – or absent – confined space planning can be seen throughout these case studies. See below for help to understand how the right ATEX ventilation system can be a core part of planning for a confined space project.
(Image: Source. Shared under CC BY-SA 3.0)
Confined Spaces + ATEX Ventilation: 3, How to Equip for Safety
Making sure equipment to be used in a confined space will deliver in five essential ways is a vital first step to achieve a safer working environment.
• 1, Makes the area safer: For example, an SA CYCLONE Air Mover delivers safe and reliable ventilation and fume/vapour extraction in hazardous environments.
• 2, Won’t actively trigger a hazard: The same unit boasts ATEX/ UKEX and IECEx certifications to give the assurance that the equipment itself cannot cause an ignition source, a crucial performance factor for obvious reasons.
• 3, Delivers exceptional speed – and ease – of use: After all, reducing the spent in a hazardous area means greater safety. Fast set-up, simple controls and lightweight design should be expected from every item of equipment.
• 4, Offers proven durability to extreme levels: Robust construction to meet the unavoidable demands on equipment from a heavily industrial worksite should be clearly built into any unit by design.
• 5, Boasts exceptional reliability without compromise: Being safety-critical, the reliability of equipment in a hazardous area should be a priority factor when selecting a, for example, portable ventilation rig.
Ventilation equipment suitable for use in hazardous areas should also meet some additional requirements.
• 1, Sufficient airflow: 20 times the volume of the confined space per hour is recommended.
• 2, Sufficient reach: Pushing fresh air into a space, as opposed to extracting, is generally recommended as pushed air moves into the area 30 times faster and addresses the risk caused by extraction of a pocket of polluted air remaining. Ventilation achieves this by creating a real airstream inside the entire confined space.
• 3, Sufficient distance: A ventilator should be kept clear of the confined space to avoid pushing polluted air back into the working area.
Questions? SA Equip’s hazardous area equipment specialists help clients worldwide with the right equipment for their project. Just ask. Bespoke options, developed by SA Equip’s in-house R&D team, are even available if a unique specification is needed.
Confined Spaces + ATEX Ventilation: 4, Recommended Equipment
While every product in SA Equip’s certified heat, light, air and power range is trusted globally to simply perform in hazardous environments, some specific products are commonly used for their outstanding effectiveness, easy-transport design and reliability.
• SA CYCLONE Air Mover:
Overview: a high-power portable hazardous area ventilation fan designed for safe and reliable ventilation and fume/vapour extraction in hazardous environments.
Features: Maximum airflow of 5179 m3/hr, compact design, adaptors available for 20cm, 30cm and 40cm applications.
Specification: Ta -40°C to +55°C, IP66, 458 x 349 x 590mm (l x w x h) without adaptors, 22kg
Overview: A highly flexible ducting designed to enable you to create a versatile ventilation system quickly in hazardous and extreme environments.
Features: Suitable for use in EX Zones 1 and 2, includes hanging loops and attachment straps at either one or both ends.
Specification: 10cm, 20cm, 30cm or 40cm diameters, 5m and 10am lengths,
anti-static vinyl coated polyester fabric construction with integrated steel helix wire.
Overview: For hot works, paint or dust, allows you to filter extracted air in multiple different applications.
Features: Connected inline with flexible ducting and an air mover and as the air moves through it removes particles, odours and/or dust as relevant, expelling clean air from the output.
Specification: 2500m3/hr, pressure drop 340pa free airflow with 30cm connectors or 2500m3/hr, pressure drop 300pa with 40cm connectors, 970mm(l) x 665mm(w) x 740mm(h), 50kg (without carbon filters) or 100kg (with carbon filters).
Full technical specifications, options, datasheet and certifications are available for each product by following the links above.
Why SA Equip?
We’re much more than just a ‘supplier’. We help our clients across the world achieve optimal lighting, heat and ventilation results in challenging environments.
We specialise in portable EX heating, lighting, ventilation and power distribution with extreme performance built into every unit. A new hire option is available for outstanding flexibility.
Most of all, we bring almost 100 years of pacesetting service and knowledge – with a foundation in the most extreme shipping and oil industry environments – to customers across heavy industry, aerospace, defence, utilities, pharmaceuticals, distilling, power stations and more.
Simply speak to a member of the SA Equip team for help with choosing the right equipment for your hazardous area project.
(Note: nothing stated in this article is intended as, or should be considered to be, formal safety advice. Please conduct the correct legislative and policy research for your project).
See also: Illuminating Hazardous Areas, Why Combustible Dust Explosions Happen (And How to Reduce Your Risk)
