Confined Spaces & the Workplace - Union Network International : CWA Health & Safety Factsheet
CWA members who work in confined spaces are confronted with many potentially hazardous conditions. These hazards can range from an oxygen deficient atmosphere or exposure to toxic agents (i.e., plugging compounds, solvents) to the possibility of an explosion or structural and/or environmental hazards.
The initial symptoms of an oxygen deficient atmosphere are increased breathing volume and accelerated heartbeat. As the percentage of oxygen in the air decreases, other health symptoms such as rapid fatigue, nausea, and unconsciousness occur. According to the National Institute for Occupational Safety and Health (NIOSH), when the oxygen level becomes less than six percent (6%), death will occur in minutes. Oxygen content is in a safe range when it is between 19% and 21%.
CWA members may also suffer exposure to carbon monoxide, a colorless, odorless, and tasteless gas, while performing confined space work. This toxic gas, produced by the incomplete burning of products like coal, wood, gasoline, oil, propane, or any product that contains carbon, can result in various health symptoms including headaches, dizziness, drowsiness, and nausea. Prolonged exposure to carbon monoxide can cause convulsions, asphyxiation, and possibly, death.