Oxygen Atmospheres

Based on OSHA guidelines, a confined space is considered to have safe oxygen levels if readings are between 20.8-21 percent, while a space with readings of less than 19.5 percent are considered to be oxygen deficient. To be oxygen deficient, such factors as rusting metals, coatings, or paints may be present. For those spaces with oxygen levels of 22 percent or more, the area is considered to be oxygen enriched due to such factors as chemical reactions or leaking oxygen hoses or torches. In these situations, the threat of fire or explosion can be quite high, thus prompting more and more companies to invest in sophisticated wireless gas detection technology.

Testing Prior to Entry

Based on OSHA regulations, certain types of confined spaces must be tested prior to entry. These include spaces that have been sealed, non-ventilated spaces that have been freshly painted, spaces that contain flammable liquids or gases, or spaces that contain liquids, gases, or solids that are toxic, corrosive, or irritant. Upon testing being completed, any confined spaces found to be oxygen deficient must be labeled as “Not Safe for Workers,” while those that are oxygen enriched are labeled “Not Safe for Workers” as well as “Not Safe for Hot Work.”

Shutdown Sequencing

For companies that have installed wireless gas monitors in their facilities, one of the biggest advantages is having the capability of shutdown sequencing. With this technology, wireless gas sensors can detect dangerous levels of oxygen and begin shutdown sequencing procedures. Happening most often when gas mixtures vary and become out of balance with one another, individual system components can be alerted to potential problems, enabling each part of the system to initiate shutdown sequencing. Along with this feature, these systems also need less calibration, since they are designed to regulate air on-site. By doing so, employees and equipment can be better protected from potential disaster.

Learn More About Safe Oxygen Levels

While it can be difficult at times to keep up with the latest OSHA rules and regulations, it’s imperative to do so when it comes to oxygen levels regarding confined spaces. If you need to gain a greater understanding of this topic and the types of monitoring systems that can guard against serious issues occurring, contact Global Detection Systems and speak with an Applications Engineer who has specialized knowledge of these problems.

1. What is a confined space?
OSHA regulations 29 CFR 1910 define this as any space large enough for employee entry which also has limited means of entry or exit and is not designed for continuous occupancy. Permit-requires space are any confined space that:

• Has the potential to contain hazardous gases;
• Could have materials that might drown or smother employees;
• Is configured with angles or narrow openings that could trap or smother a person;
• Contains any recognized safety or health hazard.

All such spaces must be equipped with a confined space monitor. Some examples of a confined space might be sewers, silos, bins, tanks, tunnels, and ventilation or drainage systems.

2. Hazardous gas
Learn all the possibly dangerous gases that could be encountered in that space, including deficient (asphyxiation) or enriched (explosive) oxygen levels. This is important to selecting the right monitors to ensure safety. You need a monitor capable of detecting OSHA-defined hazards such as oxygen, flammable gases, and toxic gases used or formed as a by-product of industrial processes. Monitors should also be capable of continuous operation to ensure safety, not just initial readings.

3. Technology
It is important that you understand the different types of gas monitors and their appropriate use, such as catalytic diffusion, electrochemical, or infrared monitors, all of which have varying degrees of value in assuring safety under different conditions. It’s also important to understand feedback from the confined space monitor via displays, electronic signals, alarms, or other means to best alert confined space workers and other employees to emergency situations.

4. Maintenance and Calibration
Proper calibration and maintenance of your monitors is import to assure accurate readings and troubleshoot any instrument problems. Familiarity with keeping devices in peak operation, such as scheduled calibrations, battery checks, and proper cleaning of sensors are important as incorrect reading could endanger lives.

5. Operation
All employees, including maintenance workers and supervisors, should receive adequate training on how to read and maintain their confined space monitors, particularly portable instruments which must be at peak efficiency despite changing environments and the bumps and jostling that result from constant movement. Monitors and training should also include any complementary equipment such as probes, carrying cases, battery chargers, and other accessories, including calibration stations and docking stations.

Educating everyone concerned is the best way to ensure everyone stays safe.

Choosing the right instrument, implementing training programs, familiarity with OSHA requirements, and understanding of the manufacturer services supporting your monitors will prove invaluable in protecting workers in confined spaces.

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