Few would disagree that OSHA’s Permit Required Confined Spaces standard has improved confined space safety and awareness over the past twenty-two years. The implementation of the new Confined Spaces in Construction standard, which OSHA published in May, is expected to further improve confined space safety. However, despite regulations, nearly 100 employees a year (on average) die in confined spaces in the United States. Clearly, there is still room for improvement.
Some of the deaths, of course, are due to a simple lack of compliance with existing standards. But others appear to result from gaps in existing standards and confusion about what is required for confined space entry. NFPA 350, Guide for Confined Space Entry and Work, scheduled for release this November, will address these gaps, minimize confusion, and provide practical guidance on how to apply requirements in existing standards to improve confined space safety. Three of the key standards used in confined space entry in the U.S.—OSHA 1910.146, Permit Required Confined Spaces; ASSE Z117.1, Safety Requirements for Confined Spaces; and OSHA’s new 1926 Subpart AA Confined Spaces in Construction—admittedly provide minimum performance-based requirements. Performance-based standards focus primarily on the desired outcome—in this case, preventing injuries and fatalities in confined spaces. However, performance-based standards sometimes lack sufficient guidance on how to reach that desired outcome. This is where NFPA 350 fills the void, providing many of the “how-to’s” for confined space safety that will help employers comply with one of the performance-based confined space standards. NFPA 350 provides guidance beyond the minimums, fills in some gaps in safety, and simplifies terminology that can create confusion when applying confined space standards. NFPA 350 is organized so that a facility can utilize the document as a whole, or use particular chapters to bolster an existing confined space entry program. For example, employers who wish to improve their confined space entry program can implement NFPA 350 in stages, perhaps improving their gas monitoring program, then moving toward improving hazard controls or competencies as the program evolves. CONFINED SPACE, PERIOD Perhaps one of the most confusing parts of confined space safety is the terminology used by safety professionals and regulators to describe confined spaces. The terms “confined space” and “non-permit confined space” can be used interchangeably to describe a confined space where no hazards are present. However, this same space becomes a “permit-required confined space” the very next day when an employee enters it to weld or paint. The type of space is different from day to day and depends on what is being done inside the space. Furthermore, there are several different procedures that can be used for entering permit-required confined spaces. “Reclassification procedures” are allowed in spaces where all hazards have been eliminated. “Alternate procedures” are allowed where the only hazard is atmospheric and is controlled by ventilation. A full permit is needed for entry where other hazards exist. Even confined space professionals have expressed difficulty over how to best explain the differences in requirements for entry to employees 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 hazard. All spaces that meet the OSHA definition of a confined space are referred to simply as “confined spaces” in NFPA 350.
The guide also establishes one procedure for all of those spaces, starting with the pre-entry evaluation form. NFPA 350 does not distinguish between a reclassified space and an alternate procedures entry. 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 using a checklist to evaluate all spaces prior to issuing a permit is already in practice in some industries. The change in terminology does not conflict with OSHA or ASSE regulations or standards. Rather it promotes safety and simplifies the application of requirements: look at the space, determine whether it’s a confined space, and if so, perform a hazard assessment and document it as part of the pre-entry evaluation. CONFINED SPACE IDENTIFIED: WHAT NEXT? OSHA requires a cognitive assessment of a confined space to determine whether hazards exist that would make it a permit-required confined space. If no hazards exist or potentially exist, no further action is required. Currently, OSHA does not require documentation of that hazard assessment, and the evaluation of whether a hazardous atmosphere potentially exists can be performed without monitoring. In NFPA 350, all confined spaces are evaluated using a pre-entry evaluation form, a signed checklist used to identify and document hazards that are inherent, introduced, or adjacent to the space. NFPA 350 takes one additional precaution at this juncture and recommends atmospheric monitoring prior to any confined space entry. Those results are also recorded on the pre-entry evaluation. The default position is to perform atmospheric monitoring prior to entry into any confined space. The analogy is that you should “assume the dog will bite until you find out otherwise.” Because atmospheric hazards continue to be the source of many confined space fatalities, the NFPA 350 Technical Committee decided that the few minutes it takes to perform atmospheric monitoring is time well spent to verify that there is no hazardous atmosphere. If no physical or atmospheric hazards are found, the pre-evaluation form is signed and no permit is needed. The pre-entry evaluation form can also be used as the written certification required for entry using reclassifications or alternate procedures 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-TO’S OSHA confined space standards require hazards to be evaluated and controlled but do not provide much guidance on how to approach the process of hazard evaluation and control. 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, Chapter 7, Atmospheric Monitoring, explains selection of the appropriate gas monitor, calibration procedures (including zero and bump test), and interpretation of results (including information on interferences and limits of detection). The chapter also includes best practices for gas monitoring such as shutting down ventilation prior to initial monitoring, testing to determine the amount of time for a sample to travel through a length of tubing and be detected at the sensor, and establishing safe levels for entry. Chapter 9, Ventilation, explains the limits of natural ventilation in a confined space and explains how to select and configure ventilation equipment in a confined space. Information is provided on ventilation of inert atmospheres and bonding and grounding of flammable or combustible atmospheres. Drawings of typical ventilation configurations are provided in an annex. ADDRESSING GAPS Gaps identified in existing standards have also been addressed in NFPA 350. Throughout the document, NFPA 350 references hazards that are inherent, introduced, or adjacent to the confined space. While most confined space entry programs incorporate the evaluation of inherent and introduced hazards, few address adjacent hazards. The incorporation 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. Some of the confined space incidents that have occurred since the implementation of OSHA’s Permit Required Confined Spaces standard include fatalities related to hazards such as hot work in and adjacent to confined spaces, fatalities related to inert atmospheres, and fatalities due to lack of knowledge and understanding for those involved in confined space entry. There have been several incidents 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. NFPA 350 recommends signage for inerted tanks to alert employees of the hazard of such atmospheres adjacent to a confined space.
NFPA 350 also recognizes that demonstrated competencies are critical for those workers involved in confined space entry and work. In addition to the entrant, attendant, and entry supervisor roles defined by OSHA, NFPA 350 provides recommended competencies for those who perform tasks such as gas monitoring, ventilation, and rescue. This doesn’t mean that NFPA 350 recommends additional workers be assigned to the confined space entry. However, an attendant who is also responsible for atmospheric monitoring and ventilating should have demonstrated abilities and knowledge to perform those tasks. For example, the “Gas Tester” as defined in NFPA 350 should be qualified beyond simply knowing how to turn on the gas monitor and record results. This individual should also understand how to calibrate and interpret atmospheric monitoring results. Likewise, an attendant who is also responsible for ventilating should understand the equipment and method required to maintain safe atmospheric conditions in the space. A number of NFPA 350 Technical Committee members are rescue experts who recognized gaps in rescue provisions in existing regulations. Therefore, NFPA 350 now provides the organizational elements of emergency preparedness that are normally in place in a fire department but not necessarily in a facility rescue program, and provides a tiered approach to response. In addition, the rescue chapter includes information on pre-incident planning and evaluation, rescue gear, rescue configurations, and rescue competencies. The document works in conjunction with NFPA 1670, Standard on Operations and Training for Technical Search and Rescue Incidents, for technical aspects of confined space rescue. ADDITIONAL INFORMATION Since many confined space incidents relate to change, a chapter on management of change (MOC) has been included in NFPA 350. The MOC system identifies and evaluates potential effects of modifications to confined space configurations, equipment, materials, content, and work tasks. A sample MOC form, provided in an annex, serves to document that the effects of change have been considered. Finally, NFPA 350 provides a chapter on prevention through design (PtD) specifically for confined spaces. The PtD concept seeks to initiate a design process to reduce or eliminate inherent risks and hazards associated with the design of facilities, equipment, and products. PtD can minimize retrofitting control costs and the use of labor-intensive administrative hazard control measures. PtD targets two types of interactions: the construction and/or installation of new confined spaces; and the redesign, retrofit, and/or renovation of confined spaces to eliminate, control, or minimize hazards. While the implementation of methods provided throughout NFPA 350 will improve confined space safety, the only way to fully prevent confined space incidents is to eliminate the confined space completely through design or redesign.
NANCY PEARCE, CIH, is senior fire protection engineer at NFPA and vice chair of AIHA’s Confined Spaces Committee. She can be reached at (617) 984-7439 or
Development of NFPA 350
All NFPA documents can be viewed online free of charge by going to NFPA’s website at[document number]. Individual copies can be purchased in a variety of formats. NFPA 350, Guide for Safe Confined Space Entry and Work will be available at in November. NFPA is a private, non-profit organization that develops codes and standards through a consensus process approved by the American National Standards Institute (ANSI). This process brings together volunteers representing varied viewpoints and interests to achieve consensus on fire and safety issues. In addition to input from Technical Committee volunteers, the NFPA process encourages interested parties outside the committee to provide input on the document. The Technical Committee for NFPA 350 includes experts in confined space safety from industry, labor, enforcement, government, and rescue. The preliminary draft of NFPA 350 was posted for public input in September 2013 and was revised based on that input. The Committee developed a second draft that was posted for public comment in September 2014. The final version of NFPA 350 was revised after considering those comments. 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. NFPA 350 will open for public input again in autumn 2016. To be notified about any activity related to NFPA 350, such as where and when meetings will occur or when the document is open for public input and comment, sign up for e-mail alerts on NFPA's website.
Above and Beyond The Minimums
An Overview of NFPA’s New Guide for Safe Confined Space Entry and Work
Editor’s note: The author is an employee of the National Fire Protection Association and vice chair of AIHA’s Confined Spaces Committee.