Confined Spaces: What You Need to Know

This December’s safety stand-down dealt with confined spaces, so we thought we would discuss a little more about them and what working in them entails.

Confined spaces can be found in a variety of industries, during many applications and they can even be created inadvertently during demolition activities if proper pre-planning isn’t performed. Per OSHA, a confined space is defined as having three characteristics:

1. Having limited/restricted means of entry or exit
2. Not being designed for continuous human occupancy
3. Is large enough to enter fully and perform designed work

Additionally, there are many times when confined spaces include additional hazards such as atmospheric hazards where certain gases can change the oxygen content in the space making it dangerous to enter or toxic gases that can accumulate and make the space flammable or physical hazards (such as live, moving components or unstable substances). When these hazards or others are present, the space now is classified as a “permit-required confined space”, hence giving us the two known classifications for confined spaces:

1. Non-Permit Required Confined Spaces
2. Permit-Required Confined Spaces

The purpose of the permit is to help employees take the proper steps to verify that the space is safe to enter and/or ensure they take the necessary steps to make the space safe for entry. For example, this could include ventilation methods that must be taken to safely enter the space or designating the types of communication methods to be utilized.

(Canaries were once used in coal mines as early warning systems for toxic gas.  We do NOT recommend using them today.)

One of the most important tasks that must be completed when looking at a Permit-Required Confined Space is continuous atmospheric monitoring. There are countless case studies of fatalities across many different industries where an employee was unaware of a hazardous atmosphere inside a space and was overcome by a contaminant. Proper atmospheric monitoring must also be done throughout the entire space – floor to ceiling — because different contaminants have different “weights,” e.g. carbon monoxide is slightly lighter then air, therefore it will be towards the top of a confined space vs. the bottom where the breathable ‘air’ would accumulate. In addition, it is also important to understand how the monitoring device you are using works.

(Air monitor with pump attachment.)

For Wm. T. Spaeder, we utilize Industrial Scientific Ventis MX4 monitors. These monitors work great.  For confined spaces, however, they must be used in conjunction with a “pump” attachment which enhances the radius of the air that can be sampled for contaminants (and proper oxygen content).  Without the pump, the monitor can only test a very limited “breathing zone” encompassing about a 2’ area from the monitor’s center position.  Alone, it’s not adequate to perform the proper testing to ensure a worker’s safety.

A common question I receive regarding the monitors is “What exactly do they monitor for?”  Again, for Wm. T. Spaeder, we use a standard 4-gas monitor that monitors for the following:

1. Oxygen content
2. Hydrogen Sulfide
3. Carbon Monoxide
4. LEL (Lower Explosive Limit)

Employees must be able to understand what each of these means for them to be safe in a space because conditions can change quickly.   For example, upon initially monitoring a space, you may not obtain a reading that is high for carbon monoxide (CO), but once you introduce a new process (for us its usually welding or gasoline powered equipment) the CO levels can elevate.  Being aware of how your actions and what’s going on around the area affect the situation is KEY for ensuring a safe work environment. In accordance with OSHA regulations, Wm. T. Spaeder requires continuous monitoring of all our permit required confined spaces.

(Premit-Required Confined Space with ventilation.)

Most facilities have their confined spaces properly designated as “confined” and/or whether a permit is required to enter.  That said, there are often spaces that are not as clearly identified such as tanks, sewers, boilers, manholes, ship voids, tunnels, silos, vats and wells are things that we commonly consider confined spaces. Common confined spaces in mechanical construction are trenches on a worksite and pits used to house control valves. Such areas can contain many hidden dangers. Just because it isn’t marked as a confined space doesn’t mean that you shouldn’t exercise caution prior to entering it.

Proper personnel training is also vital for working around confined spaces.  First, you need to have an entry supervisor.  Typically, this is going to be the crew foreman.  The entry supervisor is to be trained in all aspects of confined spaces.  He or she needs to know the proper methods for making the space safe for entry as well as completing the permit checklist. Second, you have the attendant. This person has the important role of keeping contact with the entrant (we’ll get to them next) and ensures that the entrant makes it out quickly. If an emergency arises, the attendant tells the entrant to exit or summons rescue when necessary. Third, the entrant, is the person going into the space to complete work. Their job is to complete their project but also to listen to the attendant. Last, is a rescue team (when applicable). This team is specially trained in confined space rescue and is on stand-by during entry operations. Some roles can be filled simultaneously, but there must ALWAYS be an attendant.  Your permit should reflect any changes to duties.

Of course, the most important part of a job is getting the job done safely. Too often, companies see employees harmed during confined space work simply because they were unaware of the hazards, or they didn’t take the steps necessary to protect themselves. By being aware of confined spaces and their dangers as well as taking the proper steps to protect those involved, projects can still be completed on time and budget though MOST importantly, each employee can return home safely to their families at night.