Page 46 - Occupational Health & Safety, August 2017

CONFINED SPACES
injuries and fatalities in confined spaces. But like most performance-based stan- dards, they often lack sufficient guidance on “how to” reach that desired outcome. NFPA 350 fills the voids and addresses these gaps, minimizes confusion in termi- nology, and provides practical guidance on how to apply requirements in existing standards to improve confined space safety.
Terminology Simplified
Perhaps one of the most confusing parts of confined space safety is the terminology used by safety professionals and regula- tors to describe confined spaces. The terms “confined space” and “non-permit confined space” can be used interchangeably to de- scribe a confined space where no hazards are present. However, this same space be- comes a “permit-required confined space” the very next day when an employee enters it to weld or paint. The type of space is dif- ferent from day to day and depending on what is being done inside the space. Fur- thermore, there are several different proce- dures that can be used for entering permit- required confined spaces. “Reclassification procedures” are allowed in spaces where all hazards have been eliminated. “Alter- nate procedures” are allowed where the only hazard is atmospheric and controlled by ventilation. A full permit is needed for entry where other hazards exist. Even con- fined space professionals have expressed difficulty over how to best explain the dif- ferences in requirements for entry to em- ployees and employers.
To minimize confusion, NFPA 350 uses one term—confined space—throughout the document, instead of renaming a space based on the presence or absence of a haz- ard. All spaces that meet the OSHA defi- nition of a confined space are referred to simply as “confined spaces” in NFPA 350.
The guide also establishes one proce- dure for all confined spaces, starting with a pre-entry evaluation form. All spaces are evaluated on their own merit based on hazards that are inherent, introduced, or adjacent to the space. Whether a permit is required for entry depends on the hazards or potential hazards identified in the pre- entry evaluation form. This approach of us- ing a checklist to evaluate all spaces prior to issuing a permit is already in practice in some industries.
Inherent, Introduced,
and Adjacent Hazards
Both the pre-entry evaluation form and the permit form remind the user to look for hazards that are inherent, introduced, and adjacent to the space. While most confined space entry programs incorporate the eval- uation of inherent and introduced hazards, few address adjacent hazards. The incorpo- ration of adjacent hazards is an important safety consideration for all confined space entry since hazards adjacent to the space can significantly affect the hazards in the confined space. There have been many inci- dents where fatalities were documented or suspected when an employee was exposed to a hazardous atmosphere adjacent to a confined space that caused the employee to fall into a confined space or led to an ex- plosion when welding was done in a space without considering the adjacent space hazards. NFPA 350 takes one additional precaution at this juncture, recommending atmospheric monitoring prior to any con- fined space entry, even if hazards are not found on the pre-entry evaluation.
The default position to perform atmo- spheric monitoring prior to entry into any confined space is akin to “assuming the dog will bite until you find out otherwise.” Be- cause atmospheric hazards continue to be the source of many confined space fatali- ties, the few minutes it takes to perform this monitoring is time well spent to verify that the atmosphere is not hazardous.
If no physical or atmospheric haz- ards are found, the pre-evaluation form is signed and no permit is needed. The pre- entry evaluation form also can be used as the written certification required for entry using reclassifications or alternate proce-
dures required by OSHA’s Permit Required Confined Spaces standard. If hazards are identified, then a permit is needed and the procedures required for safe confined space entry apply.
How-Tos
OSHA tells you what to do; NFPA 350 tells you how to do it by providing supporting information on how to identify hazards, perform gas monitoring, control hazards, and ventilate. For example, the atmospher- ic monitoring chapter explains selection of the appropriate gas monitor, calibration procedures (including zero and bump test), and interpretation of results (including in- formation on interferences and limits of detection). It also includes best practices for gas monitoring, such as shutting down ventilation prior to initial monitoring; test- ing to determine the amount of time for a sample to travel through a length of tub- ing and be detected at the sensor; and es- tablishing safe levels for entry. The chapter on ventilation explains how to select and configure ventilation equipment in a con- fined space depending on the hazard. In- formation is also provided on ventilation of inert atmospheres and bonding, as well as grounding of flammable or combustible at- mospheres. Drawings of typical ventilation configurations are provided in an annex.
Addressing Other Gaps
NFPA 350 also recognizes that demon- strated competencies are critical for those workers involved in confined space entry and work. In addition to the entrant, atten- dant, and entry supervisor roles defined by OSHA, NFPA 350 provides recommended competencies for those who perform tasks
FOR MORE INFORMATION ON NFPA 350
All NFPA documents are available for viewing free of charge by going to NFPA’s website at www.nfpa.org/[document number]. NFPA 350, Guide for Safe Con- fined Space Entry and Work can be viewed on the document information page at www.nfpa.org/350. A free downloadable fact sheet and 5 minute video as well as an online training series and information about on-site training, is also available on this page.
Like all NFPA standards, NFPA 350 is an ever-evolving document that will be revised every three to five years, making the information current and relevant and allowing for public review several times during each revision cycle. To be notified about any activity related to NFPA 350, such as where and when meet- ings will occur or when the document is open for public input and comment, sign up for e-mail alerts at www.nfpa.org/350.
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