Gas Detection and Nitrogen Awareness
Gases can be a serious threat when allowed to accumulate. Also, many hazardous gases are colourless or odourless, and companies must rely on sensors to detect them. Carbon monoxide is one example; it has no colour or smell but can cause death within minutes at only 1% concentration. Even gases that are normally harmless can become dangerous as their concentration increases. For example, 78% of the air we breathe is nitrogen, while only 21% is oxygen. However, a large volume of pure nitrogen can displace oxygen, causing suffocation. Even oxygen itself becomes toxic at concentrations higher than those in the atmosphere.
The main workplace hazards related to gases are listed below. When any of these threats are present in an area, it is considered a hazardous atmosphere. A single gas may be associated with more than one hazard.
- Direct damage to living cells
- Fires and explosions
Poisoning occurs when a gas is directly toxic for the human body, and suffocation occurs when a gas displaces oxygen and prevents breathing. For example, natural gas is non-toxic but highly flammable, and it can suffocate workers at high concentrations.
How Many Workplace Accidents Are Caused by Gases?
The Association of Workers’ Compensation Boards of Canada (AWCBC) keeps a yearly record of work-related injuries, diseases and fatalities. Injuries and diseases are counted together as time lost claims, while fatalities are counted individually. Their latest published data covers the year 2018:
- Harmful substances and environments caused 18,676 time lost claims and 652 fatalities.
- Fires and explosions caused 395 time lost claims and 6 fatalities.
This article will discuss five best practices to keep workplaces safe from gas-related accidents.
1) Testing the Air and Hazardous Atmospheres
As mentioned above, many dangerous gases are odourless, colourless, or tasteless, and this makes them impossible to detect with only human senses. Even when gas is visible, the only way to know its concentration is by testing the air. Eliminating all hazardous gases from the air is not possible, especially in the industrial sector. Therefore, a common solution is limiting the concentration of key gases, with regulations like the Canadian Ambient Air Quality Standards (CAAQS). Companies can test the air for hazardous gases, and check if their concentration is below the limit. High concentrations of gases may indicate a leak or a ventilation issue. Many air quality testers rely on chemical methods, and gases are detected based on the reactions they produce. Several testing methods may be required if many gases are present since each one has unique chemical properties.
2) Proper Training
Like any specialized device, an air quality monitor is only effective when used correctly. Even the most accurate monitoring system is useless in the wrong application, or when its measurements are not interpreted correctly. Workers who will be exposed to hazardous atmospheres must also understand the types of dangerous gases. This includes knowing where a specific gas may be found, and the symptoms of possible exposure. Staff members can protect themselves better if they know exactly what dangers are present. Nitrogen awareness is an important aspect of safety training. Since nitrogen is unreactive and very abundant, it is often used to purge toxic and flammable gases. However, since nitrogen also displaces oxygen, it can cause suffocation.
3) Using the Proper Monitor for Each Worksite
Air monitors must be selected to measure the specific gases of interest in each environment. For example, carbon monoxide and radon are measured with different methods, and you need an individual detector for each gas. In some cases, measuring several gases together is possible. For example, there are thousands of volatile organic compounds or VOCs, and many of them have negative health effects. Unless you need to detect a specific VOC, their total concentration can be monitored. Depending on workplace conditions, an air monitoring system may also need features like a waterproof or dust-tight enclosure. If flammable gases may be present, you need a monitoring system that will not create an ignition risk.
4) Continuously Monitor the Atmosphere
Workplace conditions are constantly changing, and this includes the concentration of dangerous gases in the air. For this reason, a single measurement is not enough to protect your staff. Depending on the application, some gases may need constant monitoring to alert workers when high levels are measured. Carbon monoxide monitoring is a good example since the gas can be lethal within minutes. Some gases have no immediate effects, but they can cause severe health issues over time. For example, long-term exposure to VOCs has been linked with some types of cancer. Continuous monitoring is necessary to protect workers from these gases. Air monitors can also be used to automate ventilation and air purge systems. When a dangerous gas concentration is detected, these measures are activated immediately, preventing a higher concentration.
5) Warning and Rescue System
Some gases can cause loss of consciousness and other severe symptoms within seconds. In these cases, a warning and rescue system has two important functions:
- Alerting workers, so they can evacuate an area before suffering the effects of a gas.
- Rescuing workers who were incapacitated before they could escape.
Training and drills are very important when using a system like this, to ensure that workers will know how to respond during a real emergency.
Gas detection systems are fundamental for workplace safety, especially when industrial processes use volatile chemicals. However, gases can also be a threat when combustion devices are used in homes and commercial buildings. To determine if the air is safe, the only reliable method is using a monitoring system. To protect their staff from hazardous gases, companies must provide adequate training. Workers must be familiarized with the gases they may encounter, how to measure their concentrations, and how to respond during an emergency to keep themselves, and their worksite, safe and efficient.