How can we choose the right equipment for a confined space?
Entering confined spaces is a common practice for many workers, and thoughtful selection of equipment is a critical aspect of the process.
OSHA defines a confined space as "an area that was not designed for continuous human occupancy which has limited means of entry and egress." That's the basic, straight to the point definition, but it goes on at length to include other criteria like engulfment hazards, potential atmospheric hazards (harmful substances, oxygen concentration, explosive atmosphere), tapering design, unguarded machinery, and excessive heat.
(Learn about The Dangers of Gas in a Confined Space.)
A confined space seems like a simple concept, but in practice it defies straightforward definition. There are so many things to think about before a confined space entry takes place, and much of this consideration is done formally, well before any work starts.
Each static site should have an inventory of their confined spaces completed, so that hazard controls can be premeditated. Depending on the requirements of the jurisdiction, a code of practice may be needed, monitoring requirements codified, training needs established, and some basic safe job procedures laid out.
(Learn more about The Hierarchy of Hazard Controls.)
One thing that will be required almost anywhere will be a proper hazard assessment with documentation. A formal hazard analysis considering standard confined space entry hazards is used in conjunction with a field level hazard assessment (FLHA), considering hazards relevant to that specific task on that day and time. This document is where workers have a chance to anticipate any hazards that are non-standard for this task but may require extra controls. The findings of that assessment may dictate additional equipment requirements (e.g. non sparking tools, intrinsically safe electronics).
To get right down to it, the hazard assessment is going to be the major source for choosing the right equipment for a confined space. Hazards associated to the space are evaluated and controls chosen, which could include PPE, respiratory protection, lockout procedures, permitting procedures, and monitoring requirements.
Certain requirements are predefined within industry standards and these serve as the starting point for specific equipment selection. Gas monitors, for example, are required for pre-entry testing and continuous testing while the space is occupied. At a minimum, monitors must be able to detect oxygen level, the presence of flammable gases, and levels of any toxic substances that may be present. The latter, in particular, requires a hazard assessment to establish which chemicals have the potential of being in or around the space. If they can't be reduced below the occupational exposure limit with engineering controls, other actions may be triggered such as a breathing protection requirement.
Some workplaces will also establish a code of practice. This is a company-specific document that details equipment needs and other requirements for confined space entry. It is where an organization can set its own standard for what equipment is to be used for confined spaces, provided it meets a minimum regulated standard.
To sum it up: equipment is chosen based on the hazard assessment, applicable standards, and the code of practice. Together, these three types of documentation will ensure that the equipment used is fit for purpose, available at the site, maintained appropriately, and helps provide for safe confined space entry.
For all things Confined Space, check out our Confined Space Knowledge Center.
More Q&As from our experts
- What is the best kind of gas detector to use in confined spaces?
- What types of gas should I watch out for when working in a confined space?
- What are the most common toxic gases in confined spaces?