There is a complex relationship between pressurised gas cylinders and fire.
On the one hand, pressurised oxygen can pose a real fire risk, and home users of medical oxygen need to be aware of the hazard, and take steps to minimise risk. On the other hand, pressurised breathing air is essential to firefighters in their work – fire brigades worldwide depend on Self Contained Breathing Apparatus (SCBA) to breathe in hazardous situations so they can control fires.
In this post, AMS Composite Cylinders Director, Steve Langron, explores the topic.
In addition to looking at the fire risks associated with medical oxygen and the safety precautions users can take, he also explores the practical applications of pressurised gas in firefighting, exploring some of the design features that enable cylinders to perform in hazardous environments.
Medical oxygen and fire – the risk
Home oxygen therapy is being used increasingly in the home, for the treatment of patients with a range of respiratory conditions, including asthma and Chronic Obstructive Pulmonary Disease (COPD). These therapies rely on high pressure oxygen cylinders.
This delivers a huge number of benefits to patients, improving both quality of life and survival rates by raising oxygen levels in the blood, slowing the rate of progressive pulmonary hypertension, preventing ventricular hypertrophy and reducing the risk of polycythaemia.
However, oxygen rich environments also significantly increase the risk of fire. The higher the concentration of oxygen in an environment, the higher this risk – fires start more easily, and burn faster and hotter than in ordinary air. In extreme cases, something as simple as a pilot light flicking on, or a static spark from rubbing fabrics can cause a serious fire.
Real world risks
Patients can require up to 15 hours of cylinder oxygen therapy each day, which can significantly increase the risk of fire. According to a report from BPR Medical:
“A report in 2017 by the National Fire Protection Association (NFPA) recorded a likely average annual death rate for home fires involving oxygen administration equipment of 70 people (or 3% or all home fire deaths), based upon figures between 2011 and 2015. The NFPA also reports that US hospital emergency rooms deal with an average 1,190 cases of burns each year as a result of home oxygen fires and that these fires or burns are becoming more common.”
Should a fire start elsewhere in the home, then the pressurised gas cylinder itself can be an additional fire hazard – if engulfed in flames, there is a real risk of explosion and/or increasing the severity of the blaze.
Pressurised cylinders and fire safety
Pressurised gas cylinders do have some fire safety features built in. In Europe all tubing systems for Oxygen cylinders must be fitted with a firebreak – a flame or heat activated device that blocks the cannula providing oxygen to the patient in the case of fire.
Effective fire prevention is the best way to stay safe. Here are a few best-practice steps medical oxygen users can take to minimise the risk of fire outbreaks:
- Always read the oxygen device instructions, and ensure you fully understand them before use
- Always keep a fire extinguisher in the room when using oxygen
- Never cover or place anything over the oxygen supply
- Never smoke whilst using medical oxygen, or near to the medical oxygen supply
- Oxygen supplies should be kept at least 1.5m (five feet) away from fires, stoves, ovens, grills, open flames, heating elements and other heat sources.
- Oxygen cylinders should be kept at least 1.5m away from electrical appliances that make sparks, such as electronic igniters, toasters, space heaters, hair dryers or electric motors
- Do not use flammable aerosols or sprays near any oxygen supply, as these may spontaneously combust
- Take steps to minimise the risk of static electric sparks near the oxygen supply. This includes using synthetic blankets near the oxygen supply
- Avoid using cosmetic oils, waxes, creams or greases that could be flammable – these could easily catch fire in oxygen-rich environments
- Use a room humidifier to reduce the likelihood of static sparking
In case of fire
Should an oxygen user be involved in a fire at home, then the advice from the Fire Brigade is as follows:
- Do not approach the cylinders or operate the valve
- Raise the alarm
- Evacuate the area
- Contact the Fire Service
Although there are risks to using medical oxygen, it’s important to remember that it is safe to use, as long as the proper precautions are taken.
Pressurised Oxygen and Fighting Fires
Conversely, pressurised cylinders are an integral part of a fire-fighter’s arsenal. A breathing air gas cylinder forms part of the standard SCBA (Self-contained breathing apparatus) equipment, enabling the firefighter to breathe in hazardous, dangerous environments, for up to 30-35 minutes at a time.
When it comes to choosing the right cylinder for fire-fighting, there are a few key differences. First, the design emphasis is on heat and flame-resistance, instead of cost. This increased fire-resistance enables systems to perform at the scene of fire, in hazardous environments, without endangering the firefighter.
Another key consideration when designing SCBAs for fire departments is weight. Typically, a firefighter’s equipment weighs around 20kg – which can increase to 35KG when carrying additional specialist equipment.
Taking steps to cut this weight to a minimum is essential, and small weight savings make a big practical difference. Using lightweight carbon composite cylinders instead of aluminium can reduce the load by 35%. For example, the typical 6.8 litre cylinder from AMS Composite Cylinders weighs just 3.9kg.
Lightweight Carbon Composite Cylinders from AMS
AMS Composite Cylinders is the exclusive continental European and UK distributor for an advanced range of lightweight gas cylinders from Advanced Material Systems (AMS).
Products include carbon composite cylinders for a wide variety of breathing air and oxygen therapy applications, including healthcare, respiratory, SCBA (Self-Contained Breathing Apparatus), laboratory, emergency and environmental uses.
Our light composite gas cylinders offer high pressure (300 Bar), NLL (Non-Limited Life) performance, and are accredited for use worldwide – holding a wide range of quality assurance accreditations, including: ISO 11119-2, UN-TPED Pi, DOT (USA) and TC (Canada).
Additional information about AMS Composite Cylinders and our products can be found at: www.ams-composites.com.