In general industry today, employees are occasionally required to work in confined spaces not designed for normal occupancy. Examples of these types of places include, but are not limited to, storage tanks, sewers, underground vaults, silos, and pipelines. These types of confined spaces involve the dangers of entrapment, engulfment, and hazardous atmospheric conditions. Due to these hazards, it is the responsibility of employers to identify confined space requirements and to mitigate the dangers to the lowest possible level. This is typically accomplished via training and a written program that meets the requirements set forth in federal regulations.
The Occupational Safety and Health Administration (OSHA) sets the standards for permit-required confined spaces with 29CFR 1910.146, which applies to all general industry. This standard was introduced on January 14, 1993 and became effective on April 15, 1993. However, the proposal for this standard began many years earlier after the review of accident data revealed a need for regulation.
OSHA released a Notice of Proposed Rule-making (54 FR 24080) in June of 1989, after determining that asphyxiation was the leading cause of death in confined spaces. An OSHA review of accident data also found cases of victims being burned, coming in contact with moving augers, and being crushed by rotating parts inside machinery. OSHA believes that, as noted in the NPRM (54 FR 24098), the failure to take proper precautions for permit space entry operations has resulted in fatalities, as opposed to injuries, more frequently than would be predicted using the applicable Bureau of Labor Statistics models (www.OSHA.gov).
While determining what the rulemaking should consist of, OSHA studied information already gathered by the National Institute for Occupational Health and Safety (NIOSH), American National Standards Institute (ANSI), and the American Petroleum Institute. The hearings for this rulemaking were closed on certified on November 9, 1990. Less than three years later the standard would be in effect. However, the regulation was amended in 1998 to further enhance employee participation in the confined space program, which allowed for further protection, and it stands as the current federal regulation today.
OSHA uses the term "permit-required confined space" (permit space) to describe a confined space that has one or more of the following characteristics: contains or has the potential to contain a hazardous atmosphere; contains a material that has the potential to engulf an entrant; has walls that converge inward or floors that slope downward and taper into a smaller area which could trap or asphyxiate an entrant; or contains any other recognized safety or health hazard, such as unguarded machinery, exposed live wires, or heat stress (www.OSHA.gov). According to the “General requirements” in 29CFR 1910.146, it is the responsibility of the employer to determine if any work spaces are permit-required spaces. One...