Page 14 - OHS, July/August 2022

CONFINED SPACES
Individuals authorizing confined space entry must have complete knowledge of the space’s contents and hazards.
■ Immediately dangerous to life or health (IDLH) atmosphere which poses immediate threat of loss of life, may result in irreversible or immediate severe health effects and may result in eye damage, irritation or other conditions which could impair escape.
These risks make it critical to monitor air quality around you in real-time. Oxygen deficiency or enrichment conditions, as well as hazardous vapor and gas concentrations must be detected with reliable instrumentation.
While ventilation systems are frequently used to supply fresh air into a confined space in order to maintain conditions, these may not necessarily eliminate hazards. They can provide atmospheric stability within the space.
When choosing a portable or wearable gas detector, it’s important to consider not only durability, sensor technology and battery life, but also that device’s connectivity to cloud-based software solutions with fleet management and data collection capabilities. Having such data can create additional awareness around the devices and the workers using them so that safety programs can be adjusted quickly and proactively.
Respiratory Protection
The hazardous atmospheres within confined spaces also make proper respiratory protection critical to helping keep workers protected in these environments.
Respiratory protection should be selected once confined space atmospheres have been analyzed and should be provided to all confined space entrants. Recommended confined space respirator types include: SCBA (self-contained breathing apparatus), dual- purpose SCBA, combination air-line respirators with escape cylinder, air-purifying respirators and escape respirators.
Because these devices vary in design, application and protective capability, it is important to first assess worksite contaminant levels as well as stay up-to-date with respiratory protection device limitations to help ensure you choose the right option for your needs. Some respirators may be used for various hazardous environments but if conditions reach IDLH levels or oxygen deficiency, only the highest levels of protection are required.
SCBAs provide the highest level of respiratory protection for confined space applications. SCBA are equipped with user- worn air cylinders that provide dependable, yet limited air supply without hoses or tethers to impede movement.
Major SCBA components include an air cylinder, low-
pressure warning device, regulator, facepiece carrier and harness assembly. SCBAs are useful for confifined space applications with entrances large enough to accommodate an entrant wearing the apparatus and cylinder; low-profifile cylinders are available for tight confifined space entrances. Under no circumstances should the entrant enter a confined space that contains a hazardous or potentially hazardous atmosphere unprotected and wait to have SCBA equipment lowered to him or her.
OSHA requires SCBA or combination pressure-demand airline respirators with escape cylinders for entry into IDLH environments. It must be noted that if using an airline respirator with escape cylinder, the user may not use the escape cylinder for entry and must be using the airline as the primary air source, since the cylinder is for escape only.
For both SCBA and combination airline apparatus, Grade D breathing air is regulated down from higher pressures to be delivered to the facepiece in response to breathing demand. Pressure demand respirators maintain a slight positive pressure to the facepiece at all times, which helps to prevent inward contaminant leakage.
In general, SCBAs are available in both low-pressure (either 2216 or 3000 psig) and high-pressure (4500 or 5500 psig) units. For a given cylinder size, high-pressure units have greater storage capacity, enabling longer service life. With high-pressure devices, SCBA users can select from 30-, 45- or 60-minute-rated cylinders. Thirty-minute-rated cylinders are used with low-pressure SCBA.
Head Protection
Head protection should be worn by all workers entering confined spaces. Type 1 helmets protect the wearer from top impact, while Type II helmets protect the wearer from top and lateral impact. The necessary protection should be determined by the employer based upon hazards within a specific work area. For confined spaces specifically, consider Type 1 hard hats with a low-profile design, allowing for improved range of motion during entry and exit.
Before entry into confined space work areas, all equipment should be inspected carefully before each use. Any equipment that shows any signs of wear, damage or doesn’t pass the inspection should not be used. Due to various risks and the number of different equipment that can be used, all personnel involved in confined space entry, including supervisors, entrants, attendants and rescue personnel, should be well trained. Individuals authorizing confined space entry must have complete knowledge of the space’s contents and hazards. All confined space workers must fully understand their duties prior to entry or if there are changes in assigned duties or confined space applications. An understanding of what defines a confined space and the necessary PPE for confined space work can help ensure worker safety during entry and exit.
Anne Osbourn is the Marketing Manager for Fall Protection in North America at MSA Safety. With over 9 years of marketing and product development experience, Anne joined MSA in 2015 and has worked as a product line manger in both Respiratory, and Fall Protection roles. Anne’s primary focus is to understand and deliver the needs of Fall Protection products to the construction segment in North America.
14 Occupational Health & Safety | JULY/AUGUST 2022 www.ohsonline.com