We’ve previously looked at the dangers of oxygen (O2) depletion and its effects on the human body. However did you know that high levels of O2 can also be dangerous?
Enriched O2 is used in several industries including diving, hyperbaric oxygen therapy (HBOT), gas production and gas blending stations, medical gases such as nitrous oxide (N2O) and O2 mixes, mining, steel manufacture and metal refining, aquaculture and glass manufacture.
The main concern when using enriched O2 is the risk of a build up of this gas in the atmosphere. Increasing the level of O2 past the normal 20.9% which is present in the atmosphere will increase the flammability of any combustible matter.
This is because there are three elements a fire needs to ignite, which are fuel, heat and an oxidising agent (usually O2).
Materials such as aluminium, steel and stainless steel are hard to burn in normal atmospheric conditions, but wood can easily burn due to its ignition temperature being much lower than steel.
By raising the concentration of O2 in the atmosphere, this causes the auto-ignition temperature of materials to decrease and their flammability range increases.
Materials that cannot be ignited in normal air may burn in an O2 enriched environment, while materials that do burn in air will burn hotter and faster.
Even clothes can trap and hold enriched O2 within the weave of the fabric and if they are near an ignition source, they can easily catch fire.
The HSE state that employers are legally required to assess the risks in the workplace, and take all reasonably practicable precautions to ensure the safety of workers and members of the public. This includes a careful examination of the risks from using O2. They state that even a small increase in the O2 level to 24% can create a dangerous situation as it becomes easier to start a fire, which will burn hotter and more fiercely than in normal air, and it may be impossible to put the fire out.
The Occupational Safety and Health Administration (OSHA) determines the acceptable levels of the O2 are between 19.5% and 23.5%.
O2 is colourless, odourless and tasteless, making it hard to detect the presence of an O2 enriched atmosphere.
If you store or operate with high levels of O2 you need to monitor the atmosphere, as a leak of enriched O2 could prove to be a fire risk.
Analox’s Safe-Ox+ is an O2 enrichment and depletion monitor which can be used for monitoring enriched O2 in the atmosphere.
The Safe-Ox+ consists of a wall mounted main sensor unit and a repeater. The sensor uses electrochemical technology to monitor the levels of O2 and is ranged from 0 to 25% with one low and one high audio/visual alarm. The sensor has a very long life and calibration is only required every 12 months, making it the ideal solution to help protect you from an O2 enriched environment.
Author: Araminta Hartley
Founded in 1981, Analox Sensor Technology provides niche and custom gas detection solutions to industries including beverage and fast food, commercial diving and laboratories. Analox has over 325 years of collective, specialist electronics and software engineering expertise, as well as a worldwide distributor network. Contact us to see how we can provide expert gas monitoring solutions and help you achieve your goals.