While atmospheric hazards have historically been the cause of the majority of fatalities in confined spaces, in more recent years, it appears that the safety hazards are taking over as the leading cause of confined space fatalities. Common safety hazards responsible for fatalities in confined spaces include explosions, engulfment by solids, drowning, entrapment, falls, and contact with electrical, mechanical and hydraulic energy sources.
Because confined spaces are not designed to be “occupied”, they often contain exposed electrical and mechanical equipment that would normally be covered and guarded in occupied areas. In addition, the likelihood of contact with equipment and energy sources is increased since the work space is usually smaller and more confined.
Loose or liquid materials can engulf and trap a worker in seconds. A worker walking on top of finely divided solid materials such as grain can be drawn into these materials when there are unseen voids in the materials below. The sudden, rapid release of water or liquids into a confined space can lead to drowning.
Falls in confined spaces are a common factor leading to fatalities in confined spaces. Not only can workers die from injuries but in some cases workers who fall into liquids end up drowning in small quantities of water, sewage.
It is critical that all physical and safety hazards be identified and eliminated prior to confined space entry. All electrical, mechanical, hydraulic and other sources of energy must be de-energized prior to entry to the extent possible in accordance with OSHA’s lockout/tagout standard 1910.147. Chemical or liquid lines must be drained, disconnected, isolated and blocked to ensure that there is no possible liquid flow into the area while a worker is in the space. Moving parts must be physically guarded to prevent injury.
There are numerous other hazards in confined spaces that, while less likely to cause a fatal injury, can significantly impact worker health and safety. These include temperature extremes, poor lighting, rodents, spiders, snakes and other critters. Noise can be a concern in confined spaces due to magnification and reverberation of tools and heavy machinery used within an enclosed space. Elevated noise levels not only impact worker’s hearing but also mask gas monitor alarms and hinder communication with attendants.
Before entering a confined space, ALL hazards must be evaluated and eliminated to the extent possible. Those that absolutely cannot be eliminated must be controlled to provide a safe environment for entry.
NFPA is in the process of developing a Best Practices Document for Confined Space Entry. The document will include detailed information on how to evaluate and control safety hazards in confined spaces. You may wish to sign up for the alerts for the document that is being developed by going to www.nfpa.org/350 and clicking on the SIGN UP FOR EMAIL ALERTS link above the tabs. An email will be sent notifying you of any meetings or additions to the document information page related to the confined space document. If you have ideas for what should be included in this document or would like to be involved in document development please let us know! Task groups to develop draft chapters of the document are now being formed. If you have an interest or special expertise in a particular area let us know how to contact you!