You were well aware that cave-ins, fires, and other disasters often happen on underground construction sites. However, you always thought that your employer had a good safety record and would never put workers’ lives at risk. Now that the unthinkable has happened, you have to wonder—could the company have prevented suffocation injuries on the worksite, or was this truly an unpredictable accident?
Proper Ventilation Is Key to Preventing Suffocation Injury
The first step to protecting workers from suffocation on underground construction sites is to ensure there is enough fresh air for them to breathe on the site. If natural ventilation does not provide sufficient airflow, your employer must provide mechanical ventilation capable of producing 200 cubic feet of fresh air per minute.
In addition to airflow, air quality must be constantly monitored for presence of dust, fumes, or dangerous gas. Companies should appoint one person per shift to perform air monitoring duties before any member of the team is allowed underground. This person is responsible for testing the tunnel for:
- Location risks. The appointed competent person’s first task is to assess the location for potential inherent risks—such as its proximity to sewers, gas lines, and fuel tanks. He should also be aware of the geology of the site (soil type and permeability rates) and how the specific work practices at the job site—such as explosives and diesel engines—present a threat to underground workers.
- Testing for oxygen. Next, the competent person must test the oxygen content of the underground site. This must be done regularly to ensure that the normal atmospheric pressure remains between 19.5 and 22 percent oxygen.
- Testing for contaminants. After verifying that the oxygen level is adequate, the competent person must test for carbon monoxide, nitrogen dioxide, and any other toxic gases, dusts, vapors, mists, or fumes at regular intervals throughout construction.
- Testing for flammable gases. There are special regulations for the detection of flammable gases. For example, if the competent person detects methane or another other flammable gas, measures must be taken to increase ventilation, suspend electrical work and cutting practices, or evacuate the area. The extent of the precaution will depend on the level of flammable gas detected. If a flammable gas remains present at the site, workers should be issued proper respiration devices and be limited in the scope of their work.
The employee monitoring the air quality has a duty to inform the employer of any potential threats. In response, your employer must immediately take all necessary precautions, including posting notices at all underground entrances and evacuating the area when a threat to life is present. If you think your employer could be held liable for your construction injury, click the link on this page to tell us your story or download our FREE book, What the Injured Worker Needs to Know: Your Workers’ Comp Guide.