Even the smallest changes in the air around you can have harmful effects when working in confined spaces.
So, what is a confined space?
It is defined as a large space that humans can enter. However, due to toxic vapors and unhealthy oxygen concentrations, this space isn’t designed for prolonged stays.
There are few entry and exit points, making logistics extremely harrowing for employees. Entering inside this space can be hazardous due to sloping walls, uneven floors, and the inherent risk of engulfment.
Other than physical obstacles, confined spaces invite a range of invisible hazards, such as the presence of too little oxygen, which can result in oxygen depletion, or too much oxygen, which can result in oxygen enrichment.
Defining Oxygen Deficiency
Most regulatory bodies claim that an acceptable level of oxygen in the air is 19.5%. If it is lower, your air monitor will trigger an alarm. So why 19.5%? Why not 19.3% or 20.8%?
Look at OSHA’s definition of what constitutes a hazardous atmosphere. You’ll come across something like this, “an atmosphere that exposes employees to the risk of impairment, incapacitation, death, or the ability of self-rescue.” OSHA then goes on to state five causes of atmospheric oxygen, one of which is the concentration of oxygen below 19.5%.
Notice the careful wordplay. OSHA refrains from making absolute claims about ‘safe’ oxygen levels. Instead, it merely states that 19.5% could potentially be hazardous.
It is worth pointing out that OSHA only states regulatory requirements. It doesn’t explain how companies should meet these requirements.
Defining Oxygen Enrichment
Oxygen enrichment, which is a generic term for health hazards associated with environments containing more than 21% oxygen, is at the other end of the spectrum.
At these concentrations, the oxygen in the air increases the risk of a fire or explosion. Fires in oxygen-rich environments are more intense and produce much more heat. The most common causes of oxygen enrichment are a faulty pipe connection, a leaking oxygen cylinder, and incorrect disposal of liquid gas.
Ensuring acceptable gas levels in confined spaces involves a strategic plan with several key steps:
1. Enhance Air Circulation
Before entering a confined area, it is crucial to promote efficient air movement. This step involves thoroughly ventilating the space to eliminate any harmful gases that may have built up over time. Utilizing fans or ventilation systems can help disperse these gases and increase air quality.
2. Implement a Structured Entry System
Develop and execute a structured entry system, such as a permit-to-work system. This formal procedure is essential for controlling access, ensuring only authorized personnel enter the space, and that all safety protocols are in place. The system should detail necessary precautions and be rigorously enforced to maintain safety standards.
3. Conduct Regular Gas Monitoring
Prior to and during occupancy, testing the air quality within the space is paramount. Utilize reliable gas detectors to measure the concentration of various gases and ensure they remain within safe limits. Continuous monitoring should be implemented throughout the work period to immediately detect any dangerous changes in gas levels.
By following these steps, confined spaces can be managed effectively, ensuring safe air quality for all individuals involved.
Portable Testing Methods for Air Monitoring
OSHA clearly states that all confined spaces must be tested for oxygen content, flammable gases, and vapors.
This means that employees should not enter an area without first conducting confined space air monitoring.
A confined space air tester, commonly referred to as a portable gas detector, is an essential tool for assessing air quality in restricted environments. These compact instruments are designed to be easily carried into tight spaces, ensuring user safety by continuously monitoring air conditions.
Key Features of Confined Space Air Testers
- Multi-Gas Detection: These testers can simultaneously detect multiple hazardous gases, such as carbon monoxide, hydrogen sulfide, and oxygen levels.
- Real-Time Data: They provide immediate feedback on the air quality, allowing users to make prompt safety decisions.
- Portability: Lightweight and easy to handle, these devices are perfect for environments like tanks, silos, and underground spaces where air circulation may be limited.
Why Use a Confined Space Air Tester?
Working in confined spaces poses unique risks due to the potential buildup of dangerous gases. A confined space air tester allows workers to:
- Assess Safety Quickly: Get instant information on the air conditions before and during entry.
- Ensure Compliance: Meet safety regulations by providing documented proof of safe air quality.
- Prevent Accidents: Early detection of toxic gases can prevent life-threatening incidents.
In summary, a confined space air tester is a vital safety device for anyone who needs to enter and work in confined areas, offering peace of mind by ensuring the air is safe to breathe.
3 Methods of Measuring Confined Space Oxygen Levels
a. Internal Pump Method
These days, gas monitors come with their own built-in internal pump. This reduces the risk of dropping your equipment into the confined space since it’s always secure in your hand. The internal pump method is beneficial because it lets you take readings in real-time. Moreover, you don’t have to scroll through your results for accurate confined space oxygen levels.
b. Attached Pump Method
Most monitors are compatible with detachable pump options. The pump either uses a hand squeeze pump to draw a sample or is battery-operated.
In case the pump breaks, you will still have a fully functional gas monitor. Since the monitor is in your hand for this method at all times, there is a lower likelihood of dropping it into the confined space. Readings can be taken in real-time without the need for scrolling through peak readings for confined space oxygen levels.
With that said, it is not easy to get a hand-squeezed sample. Employees will be required to repeat the hand-squeezed sample at various stages of the remote test. There’s also the challenging aspect of having to squeeze the 10-foot hose up to 40 times in order to draw up enough air for confined space air monitoring.
In the case of battery pumps, you have to be very patient. This is because you’ll have to leave the sample tube at each layer for several seconds to get an accurate sample.
In both cases, if the filter isn’t properly clean, you may end up drawing water into the monitor. If your tubing or filter is clogged, the pump will draw air from the monitor location and not the end of your sample tubing. This will result in inaccurate readings.
c. Rope Method
Most gas monitors come with clips that can be attached to a rope. All you have to do is lower the monitor into the confined space to test the air before entry.
The rope method makes it easy to test different depths of the atmosphere and take readings at different levels if it is lowered slowly.
However, employees will have to be vigilant so as not to drop the monitor and also check for water. This is because lowering the monitor into the water will damage it.
One big disadvantage with the rope method is that it makes it difficult to figure out what readings the monitor took and at what points, during each test. The monitor keeps track of peak readings, so employees will have to scroll through the readings to evaluate the peak data in the readings.
Understanding What Gas Monitors Detect
Gas monitors are essential for monitoring confined space oxygen levels and other gases. To ensure a safe working environment, detecting the concentration of these four crucial gases is essential. Here’s a breakdown of what these monitors typically detect:
- Oxygen (O2): Vital for human survival, these monitors check if oxygen levels stay within the safe bounds of 19.5% to 23.5%. Deviation from this range can lead to harmful effects.
- Combustible Gases: These devices alert users to the presence of flammable gases, such as methane and propane. Detection is crucial to prevent explosions, expressed as a percentage of their Lower Explosive Limit (LEL).
- Carbon Monoxide (CO): Known for being a silent threat, this gas is colorless and odorless. Monitors ensure CO levels are within safe limits to prevent asphyxiation.
- Hydrogen Sulfide (H2S): This toxic gas, famous for its rotten egg smell, can be deadly at high concentrations. The monitors provide early warnings to protect workers from harm.
Depending on the specific needs of different industrial settings, some models might also offer additional capabilities, such as detecting gases like ammonia or chlorine.
By keeping an eye on these critical gases, monitors play a pivotal role in maintaining safety and preventing accidents in the workplace.
DCS Rescue is the Industry Leader in Confined Space Rescue
Worried about meeting OSHA guidelines for confined space entries? At DCS Rescue, we provide you with all the necessary rescue apparatus to fulfill regulatory requirements within confined spaces. Our rescue teams are fully equipped to help perform horizontal and vertical rescue configurations.
Each member of our confined rescue team is qualified for rope rescues, emergency medical services, as well as extractions.
Ready to get in touch with the experts in confined space rescue?