Asphyxiants in the Workplace-January 2017

IN THIS ISSUE: Asphyxiants in the Workplace

The following cases illustrate injury caused by the inhalation of asphyxiants:

  • Case #1: Using a Heliarc welder with argon as a shielding gas, a worker welds 50 pieces of cylindrical steel pieces without a respirator or mechanical ventilation. He began welding at 7:00am but felt dizzy and short of breath, and stopped welding briefly about 2 hours later. He put on a dust mask and resumed welding in the same position. He briefly lost consciousness around 11:00am and was rushed to the hospital. After being diagnosed with symptoms related to inhalation of a toxic asphyxiant airborne contaminants, he received respiratory therapy and was released.
  • Case #2: Five employees work in a refrigerated warehouse where liquefied petroleum (LP) gas powered forklifts are operated. Two faulty forklifts begin emitting more than 1,400 ppm of carbon monoxide, exposing the workers to this deadly odorless gas. Following symptoms progressing from lightheadedness to dizziness, one employee was transported to a hospital by helicopter where he received treatment in a hyperbaric chamber while the other workers were admitted to a hospital and remained overnight for treatment. After the incident, the employer obtained battery-powered forklifts for use within the warehouse, and carbon monoxide measurements detected 0 ppm.

Asphyxiants are chemicals in the workplace that either displace oxygen or restrict the uptake of oxygen.

  • Mild symptoms include headache, dizziness, nausea, and vomiting.
  • More severe exposure can lead to unconsciousness and death.
  • Effects can be immediate or progress over the work shift.

In Case #1, argon, a simple asphyxiant, removed oxygen in the ambient atmosphere and caused oxygen deprivation in those exposed. Simple asphyxiants are of particular concern in enclosed spaces and in welding operations. They are not considered toxic because they do not cause a reaction in the body, and that may lead to their hazard being minimized. Other examples of simple asphyxiants include: carbon dioxide, nitrogen, helium, neon, and argon.

Case #2 involved a chemical asphyxiant, carbon monoxide. Chemical asphyxiants are agents that prevent the delivery of oxygen from the bloodstream to cells or that disable cellular respiration even in the presence of adequate oxygen levels. Other examples of chemical asphyxiants include hydrogen sulfide and cyanide.

In order to prevent accidents involving either simple or chemical asphyxiants, do the following:

  • Identify asphyxiants used in the workplace, as well as where and how they are stored, dispensed, and used in processes.
  • Identify operations that routinely use asphyxiants such as welding and confined space entry. Make sure that only trained personnel weld or enter a confined space.
  • Educate employees who routinely work with asphyxiants on how to best protect themselves, and to how to recognize the signs and symptoms of overexposure.
  • Notify employees who may enter areas where asphyxiants may be present.
  • Establish emergency procedures to handle accidents involving asphyxiants.
  • Provide and train on-site first aid personnel.

As with any chemical or contaminant that can harm employees, it is important that the hazards of asphyxiants be recognized, evaluated, and controlled.

For more information on this topic and to discuss your company’s safety and industrial hygiene needs call OccuSafe at (214) 662-6005 or visit us at
OccuSafe Industrial Hygiene & Safety, Inc. provides skills and expertise to recognize, evaluate and control hazards and injuries in the areas of industrial hygiene, occupational safety and health. OccuSafe services companies of all sizes in a range of industries.

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