Page 48 - OHS, April 2020

CONFINED SPACES
Can an Industrial Vacuum Solve Confined Space Hazards?
From grain handling operations to heavy blast material, pit cleaning with vacuums allows workers to clean outside of confined spaces.
BY DAVID KENNEDY
44 Occupational Health & Safety | APRIL 2020
www.ohsonline.com
Two workers died this week and two will die next week, statistically speaking, in confined space-related accidents according to OSHA data that documents an average of 92 deaths and nearly 11,000 injuries per year. Of those 92 an- nual deaths, one-quarter of them occur during repair, maintenance, cleaning and inspection activities in en- closed spaces.
Despite OSHA’s spotlight on confined spaces, the number of deaths remains relatively the same as it was 23 years ago. In November last year, the National Fire Protection Agency (NFPA) released NFPA 350: Guide for Safe Confined Space Entry to provide extended guidance and best practices to fill in gaps or confusion in relation to OSHA standard CFR 1910.146.
Working in septic tanks, silos, reaction vessels, vats, boilers, holding tanks, pits or similar structures or enclosures qualifies as working in a confined space.
According to NFPA 350, “all confined spaces have the potential to become OSHA-defined permit-re- quired confined spaces, depending on the work to be performed and the inherent, potential, or introduced hazards in the space at the time of the entry.”
OSHA standards designates a permit-required confined space when it has a hazard to health or life associated with it such as containing a hazardous at- mosphere; material with the potential to engulf some- one who enters the space; an internal configuration that might cause an entrant to be trapped or asphyxi- ated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross sec- tion; and/or contains any other recognized serious safety or health hazards.
Confined Space Procedures are costly in terms of the resources needed for evaluation, training and additional manpower to monitor confined space en- try. Unfortunately, the safety procedure of provid- ing a monitor frequently ends up putting additional workers at risk since anywhere between 40 to 60 percent of all confined space deaths include would- be rescue workers.
Whether it is a confined space or permit-only con- fined space, the same health and safety hazards that typically exist on the shop floor—such as ergonomic hazards, slip and fall, overexertion, explosion, or un- controlled release of energy—also exist in confined spaces; however, in confined spaces, there is a smaller margin for error.
Any time organizations can engineer out, or minimize, health and safety hazards with controls, it
reduces risk. Therefore, using controls to minimize risk is the preferred method for handling hazards—so much so that the NFPA dedicated an entire chapter in NFPA 350 to hazard elimination and control.
Since 25 percent of confined space deaths occur during cleaning, NFPA 350 8.4.2.1 states, “whenever possible, workers should clean the confined space from the outside, without the need for entry.”
Just as each operation has proprietary processes and every enclosed space application is unique, each industrial vacuum cleaning system is different and se- lected to fit the application. In some instances, small air and electric powered drum-style units will suf- fice, while others require larger units to accommo- date multiple users and filtration systems capable of capturing particles that are invisible to the naked eye. Some, of course, will also need to be intrinsically safe.
The restriction of combustible dust in an enclosed space increases the likelihood of an explosion. In areas where combustible dust is present in an enclosed area, NFPA 350 8.4.3 addresses the need for intrinsically safe equipment and procedures, stating that “entry su- pervisors should ensure that combustible dust residue should be removed using intrinsically safe vacuums” and “confirm that vacuum equipment is grounded and bonded to the space being cleaned.”
Feed and Grain Mills
In feed and grain mills, keeping the area clean not only eliminates organic combustible dust accumula- tions, but also prevents pest infestations and product contamination. Using an industrial vacuum cleaner with wands and attachments often eliminates the need to enter a boot pit for cleaning, freeing up valu- able resources and eliminating risk of death in en- closed spaces.
Recently, a feed mill installed a breakaway vacuum system when production increases made housekeep- ing more cumbersome. Breakaway vacuum systems can be defined as somewhere between portable in- dustrial vacuums and powerful central vacuum sys- tems. These breakaway vacuum systems use powerful portable vacuum units in concert with several small tubing networks. For instance, if a user is working in a 100-by-200 square foot area and there are two more areas in another building, individual tubing networks are created and the portable unit rolled from one tub- ing network to the next and so on, providing the con- venience of a multi-inlet central vac, with the energy efficiency and flexibility of a portable vacuum.