Safety Articles

Equipment for the Dangers We Can’t See

Your crew is preparing for the day’s job. You have all the necessary tools and machinery for the coating you will apply. You have your protective eyewear and clothing to guard against physical hazards as well as respirators to protect against fumes. These are all important safety measures, but you are still not fully protected.

Not all necessary precautions are those you may expect to regularly deal with on a typical coating job, and that is the case with hazardous gases. Unlike fumes, which are limited to gases that are dangerous when inhaled, a hazardous gas is not always an inhalation danger and workers are certainly not always protected through the use of a respirator. This means that there is a definite need for reliable gas detection equipment when applying coatings in an enclosed area.

Potential Problems

Exposure to combustible or toxic levels of hazardous gases, as well as oxygen-deficient atmospheres (containing less than 19.5 percent oxygen by volume), can cause immediate death or injury to an unprotected worker. This type of exposure is responsible for various injuries and fatalities in the construction trades industry each year. Table 1 illustrates how just a small amount of exposure to carbon monoxide over a period of time can have a serious impact on workers.

       Table 1                                   
In addition to what you can breathe, combustible gases such as methane, pentane, and hydrogen present another serious hazard to workers: When they are present in sufficient quantities they also pose the threat of fire or explosion. With some gases, this can happen even at low concentrations that would never be detectable to the human senses alone.

Besides the dangers of combustible gases, there are other risks to consider. Toxic levels of commonly encountered gases such as hydrogen sulfide, carbon monoxide, nitric oxide, and nitrogen dioxide can harm workers even in low doses, and they can cause both short- and long-term damage. Low doses can cause headaches, dizziness, slowing down of the central nervous system, and even death. Chronic exposure to low concentrations can damage mental health and the reproductive and nervous systems, as well as cause chronic respiratory damage and decreased resistance to infection. Higher doses can also be fatal.

Oxygen deficiency is another hazard. It often results from oxygen-depleting gases displacing the oxygen supply in confined spaces such as manholes, tunnels, and tank interiors (see Table 2 for more examples). Effects of oxygen deficiency range from impaired thinking and coordination to rapid fatigue, unconsciousness, and ultimately death.

     Table 2
Again, it is important to remember that you cannot simply rely on your senses to tell when hazardous gases are present. Many of these gases are often odorless, making smell an unreliable indicator and opening yourself up to harmful effects. And since non-fatal toxic gas effects can be delayed, you can be applying a coating at a jobsite and complete your work, and it is not until much later, maybe even the next day, that you will realize you have been exposed once symptoms have already occurred.

Types of Sensors

Considering how many dangers there are to health and safety and how relatively simply these can be effectively monitored, the need for reliable gas detection equipment for all workers potentially affected becomes an obvious choice for jobsite supervisors to make. Single- and multi-gas detectors are continuous reading instruments that can be used easily by workers to monitor gas levels, alerting the individuals before the gases reach dangerous levels. Portable single-gas detectors are available for detecting oxygen, carbon monoxide, hydrogen sulfide, sulfur dioxide, nitric oxide, nitrogen dioxide, and other hazardous gases. In addition, many portable multi-gas detectors can be configured to detect four to five gases all at once. Sensors are normally available for the previously mentioned gases listed, but they can also include others, such as ammonia, chlorine, and chlorine dioxide.

Many gas detector models are available, but it is important to select one that is easy to use and durable. Ease of use is essential because when a worker on the job has numerous tasks to handle, the time that he or she can take to learn to correctly use a gas detector may be very short, yet it is essential that they are used correctly. Durability is a must because of the beating that any safety equipment can take on a worksite, and when a good, reliable gas detector can be a significant investment, its durability ensures both safety and financial sense.

It thus also becomes important to seek the advice and expertise of a reputable gas detection company. Not only can experts lead you to what devices will work best for your workers’ needs, but they can also share how to ensure that the investment in the detectors and your workers’ safety is most effective.

Keep Workers Safe

When gas detection becomes a normal part of your and your workers’ safety precautions, it doesn’t differ from any other piece of equipment. Safety equipment is only safe when it is working properly. Once your workers are using gas detectors, those detectors must then be calibrated on a regular basis to ensure that the readings are accurate and, therefore, truly keeping workers safe.

In the end, it’s a simple two-step process. In addition to your regular safety practices and precautions, you and your fellow workers need to first be aware of the potential and specific worksite dangers, such as hazardous levels of toxic and combustible gases and oxygen deficiency, and the environments in which they commonly exist on construction sites. And secondly, your jobsite supervisors need to be able to ensure that workers are consistently using properly calibrated gas detection devices when working in areas where hazardous gases may be present.

With a little awareness and investment, you can ensure the safety of your crew. In the end, your life and the lives of others could depend on it.

About the Author:

John V. Carvalho, III is the president of Apollo Safety, Inc. Veteran-owned, Apollo Safety specializes in gas detection products and services for portable and stationary systems. For information, please contact: Apollo Safety, (800) 813-5408,

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