Respiratory Protection for Industry
Published: 10th Oct 2002
Industry can breathe easy with modern Respiratory Protection Equipment systems
Whilst circumstances will generally dictate which form of respiratory protective equipment (RPE) is most suitable to a particular application, recent technological advancements have meant that there is now much more of a choice within those parameters.
For example, where breathing apparatus (BA) is required, design and functionality enhancements have brought about greater flexibility in use, more comfort for the wearer and improved cost effectiveness – not just for today but also well into the future. For the safety specifier, this can solve two problems – how to continue to improve wearer safety whilst saving money in the long term. It would be impossible to cover the entire RPE range in the space available. For this reason, this article will concentrate on three specific types: Emergency Escape Breathing Apparatus (EEBA), Airline and Self-Contained Breathing Apparatus (SCBA).
The Buying Decision
The PPE Directives set the basic parameters for selecting RPE but buying isn’t just about the cost today – it is about comfort, performance and the ability to keep up with new technology in the future. A lower cost system may look good on paper but if it is difficult, impractical or even impossible to upgrade in the near future, it will prove to be false economy.
For example, when considering breathing apparatus, financial implications should not outweigh the overall benefits of an upgradeable, integrated system that can continue to improve wearer safety as new technology is developed. In the same way, in general industrial applications there is no point in opting for an escape set that cannot be used by untrained personnel in an emergency.
When it comes to Standards, purchasers of RPE for use within Europe should obviously be looking for compliance with European Standards (EN), CE Marking and any additional legislative requirements of the “host” country (HSE requirements and Home Office Regulations in the UK, for example). Equipment from the USA and Australia is governed by very different standards and will not be relevant outside of those countries.
Ongoing maintenance and support is of obvious concern with equipment from “abroad” and should be an important element in the buying decision. Reputable manufacturers will usually offer a maintenance and after sales support package, particularly for SCBA, and it is essential that geographical constraints do not restrict the ability to service or repair essential equipment.
In the same way that different hazards require different levels of protection, different industries have different applications. In chemical plants, for instance, personal escape sets can be found on plant walls and may be issued to visitors for personal use in case of an incident. Those working in utilities, particularly during confined space working, will carry an escape set throughout the duration of their shift as a matter of course.
Industrial environments that present a hazard that is immediately dangerous to life and health (IDLH) will require breathing apparatus to be worn. Tank cleaning and rescue operations are typical applications but these will require a different specification of breathing apparatus than that worn by a firefighting force at a petrochem plant, for example.
The quality of air in workplace environments can be affected by a number of factors including the manufacturing process, materials used, cleaning methods and airflow.
The creation of gases and vapours can turn a previously safe atmosphere into a toxic and possibly lethal workplace area. In addition, the need to monitor oxygen levels (for deficiency or enrichment) can be as important as the need to monitor and control potentially explosive or flammable environments.
The need to assess working atmospheres is important across a number of industries. For example, the brewing industry can experience increased levels of nitrogen (used to make a more effervescent beer) which could lead to oxygen depletion and, as a result, asphyxiation. In steelworks, leaks of carbon monoxide, which is used as a process gas, can create a potentially hazardous environment. Those working in the food industry can suffer from the effects of disinfectants containing hydrogen peroxide or, in refrigeration and cold storage areas, unhealthy levels of ammonia. Telecomm and other utility workers can also find a build up of gases in confined spaces – particularly those underground.
To ensure absolute safety, employees should always perform a risk assessment to ascertain the hazards that may be present and then continue to monitor the workplace area before entering a potential hazardous environment – especially in confined spaces, an area which has its own legislative requirements. In some cases, breathing apparatus will need to be worn during this assessment.
There is no one simple way to specifically detect all gases and a variety of techniques are usually required to ensure a complete monitoring programme. For this reason some companies offer a complete range of gas detection equipment from sampling tubes through to portable, single and multi-gas monitors and fixed gas detection systems. Some also provide gas detection training courses as well as free advice on the selection and use of air sampling methods.
Personal Escape Sets
Most industries have a need for personal escape systems in one form or another. In construction work, for instance, exposure to gases or engulfment can pose a real threat, whereas pharmaceutical, steel, petrochem or gas workers will be well aware of the dangers of gases and vapours. For others, an explosion or fire could lead to smoke inhalation. Utility workers and other industry sectors that require confined space working are covered by specific legislation to ensure their safety.
Legislation makes it clear that escape sets are not breathing apparatus substitutes and cannot be worn for work or entry purposes – they should only be donned in order to make an escape.
Some can be used by untrained personnel and are generally found in and around the walls of a plant or are handed to visitors on entering a potentially dangerous area. Others are worn by trained individuals who are entering potentially dangerous areas on a regular basis and who may need to make a safe, unhindered escape (such as those working underground or in confined spaces). The right selection depends on a number of factors, one of the most important being the application.
Application 1: danger of fire – all personnel
A respiratory filter providing at least 15 minutes of filtered air to protect against the fire gases present in smoke would be an ideal solution (around 85% of fire victims are killed by fire gases as opposed to flames). The hood design must allow for it to be worn by anyone – those with facial hair, long hair or spectacles and, of course, children. Other considerations would be visor design, shelf life, location (travel case or wall box around the plant) and servicing and filter exchanges. The Draeger Parat C is a good example of this.
Application 2: potential escape from unknown hazard – all personnel
This may require breathing air for up to 15 minutes and a unit that could be used regardless of the hazard type and with minimal user training. In addition, as in application 1 above it would need to be suitable for use by anyone regardless of facial shape or facial hair. Materials used are an important consideration (flame retardant?) as well as warning devices and types of cylinder and flow.
Application 3: escape whilst wearing other forms of personal protective equipment (PPE)
This is typical of the applications faced by utility personnel and those working in confined spaces for inspection purposes, etc. The possibility of wearing other forms of PPE such as hard hats, ear defenders, etc., would favour a facemask design. Products like the Draeger Saver PP incorporate a positive pressure facemask which is first-breath activated.
Like the Saver CF, it can be supplied with spare cylinders and has a highly visible orange carrying case. An anti-static bag for potentially explosive atmospheres can also be supplied. (For both units, the mandatory routine service period is 10 years.)
Application 4: longer duration escape
Mining and other environments where the “safe area” may be some distance from the potential hazard require longer duration sets that operate quickly and so eliminate panic. These applications may require up to 30 or even 50 minutes of breathing air. An instant, panic-free oxygen supply that can be used by untrained or experienced users alike is a must.
Application 5: domestic preparedness – chemical and biological agents
Recent events have highlighted the threat of chemical and biological agents throughout the world. Toxic gases (including nerve agents, blood agents and tear gas) demand a filtering hood that can be donned in less than 10 seconds to provide up to 15 minutes of protection for children and adults alike irrespective of face shape, their need to wear spectacles or the presence of facial or long hair.
From short duration sets through to the very latest firefighting systems with electronic monitoring and automatic entry control capability, breathing apparatus has changed dramatically over the last 10 years.
Gone are the days when one set was used to cover a multitude of tasks. Today’s more modern SCBA is available in a variety of styles to suit the job in hand and is often fully upgradeable to maximise use and ensure future cost savings. More comfortable than their predecessors, lighter in weight and ergonomically designed to improve wearer acceptance, today’s SCBA systems are easy to use and straightforward to maintain.
“For example, the Draeger PA90 plus series utilises the same pneumatics throughout the range which ensures that future upgrades are not only easy to achieve but they can be carried out very cost effectively. In fact, several industrial brigades are now using the Bodyguard electronic monitoring system as part of a PA90 plus series upgrade – a Draeger enhancement that has brought fast access to a host of previously separate warning and monitoring devices within a single instrument.”
SCBA is obviously used in all kinds of extreme environments and the lighter it is, the more movement the wearer will have and, as a result, the more effective he or she will be. Recognising that, before anything else is taken into consideration, the average BA wearer is required to carry 3 kilos of compressed air, the health and safety director or manager needs to look at cylinder weight. Options such as carbon composite cylinders have been developed and are now used in industrial applications as well as by those fighting fires.
Once again, the type of BA used, will depend upon the application. Broadly speaking, these can be defined as:
Application A: Short duration
Not to be confused with escape sets, these types of BA can be worn to enter an incident – even where it is known that a hazard exists. Often used in rescue operations, they are ideal for use in confined space entry, in high security cell snatch, for inspections and by water authorities as well as fire or police command units. The sets should be light and comfortable to wear and offer up to 15 minutes of breathing protection with full working approval.
Application B: Basic compliance set – rare usage
Not everyone needs the extra padding and comfort that is available in the more sophisticated BA systems. In some applications, such as confined space or marine rescue or when working in sewers and water treatment plants, etc., the donning of a BA set is a rare occurrence. Even for one-off, sporadic use these sets must comply with current legislation.
Application C: Regular use – longer duration
Cleaning vats, silos and other work in confined spaces requires the use of full breathing apparatus, as does the rescue of personnel from any environment where a hazard might exist. Hazardous spills and clean up operations will all require personnel to don BA whilst atmospheric tests are carried out to assess the level and nature of the hazard concerned. In these applications where regular use is coupled with longer duration, comfortable, high performance sets are required.
Application D: fire fighting
Fire fighting is both arduous and dangerous and industrial firefighters are adopting the same level of sophistication in their equipment as municipal fire brigades. With more flame retardency and increased emphasis on lightweight, comfortable systems, the design of this equipment has been revolutionised in the last five years.
The burden of weight on the back is something that every firefighter has to contend with. With this in mind, studies with the Rotterdam Fire Brigade were carried out to determine the most effective method of weight distribution and body mounting of BA sets. The results showed that, by improving this physiological stress and strain, it was possible to significantly reduce the likelihood of back injuries. They also indicated that, by reducing the stress on the human body and lowering the breathing rate, firefighting tasks could be carried out with an increased safety factor.
Recognised as a standard procedure in UK domestic Fire Brigades, entry control is now impacting on industrial fire fighting forces throughout the UK.
Application E: Extended duration – toxic environments
Anyone working in potash mines will know that it is a long walk from one end of the tunnel to the next. Similarly, those performing rescue operations in vast tunnels or underground areas need to be completely independent of low-oxygen, contaminated ambient air. These situations call for an extended duration set that is light, comfortable and which can be worn in toxic environments.
Known as second-generation closed circuit breathing apparatus, these sets supply the wearer with up to four hours of breathing air. A carbon dioxide absorber removes the carbon dioxide from the exhaled air. The breathing air from the oxygen cylinder is enriched with oxygen. During normal breathing a constant dosage system ensures an adequate supply of oxygen, with additional oxygen being added automatically through a minimum valve if the breathing rate increases.
Maintenance, toxic spillage, sewer and water treatment, tunnel construction and repair, gas storage, chemicals manufacture and electricity generation are just some of the applications where airline systems are used. In general terms, airlines are used to supply variable duration, continuous air in confined spaces such as those found when tank cleaning.
Air can be fed in two ways, direct from cylinders or from a factory line. Their use must, therefore, be carefully controlled to ensure that the airline is not caught, snagged, squashed or cut, and that the air supply does not run out.
When fitted to a positive pressure facemask, airline systems provide extended protection in varying configurations, with freedom of movement and maximum safety. For telecomm applications, it can also be used to provide a communication capability, where radio transmission is impossible.
Rescued After More Than a Year in a Flooded Tunnel
“Testimony to the ruggedness of Draeger systems can be found in the true story of two sets that were stored as rescue units during a tunnel excavation. The tunnel collapsed and flooded with the sets being buried for over 14 months - all that was required when they were dug out was a hose and sponge down!”
For more information on Respiratory Protection please visit http://www.osedirectory.com/product.php?type=health&product_id=20
Published: 10th Oct 2002 in Health and Safety International