OSHA Issues Confined Spaces in Construction Proposed Rule
On November 28, 2007, OSHA has published their Proposed Rule for Confined Spaces in the Construction Industry, news release found here. The actual proposed rule can be found here.
OSHA proposal has broken the confined spaces (currently only General Industry) down from two (permit & non-permit required) to four: Isolated Hazard Confined Space, Controlled-Atmosphere Confined Space, Permit-Required Confined Space, and Continuous System-Permit-Required Confined Space.
Paragraph (b)(1)(i). A Continuous System-Permit-Required Confined Space (CS-PRCS) is a confined space that is a part of, and contiguous with, a larger confined space (for example, sewers) that the employer cannot isolate from the larger confined space. It is also subject to a potential hazard release from the larger confined space that would overwhelm personal protective equipment and/or hazard controls, resulting in a hazard that is immediately dangerous to life and health. The proposed rule includes the CS-PRCS classification to ensure that the employer recognizes that, as the construction industry has recognized, there are difficulties associated with isolating the hazards of other larger spaces connected to the CS-PRCS. Special precautions are necessary, in addition to the other PRCS requirements, to ensure adequate protection of the employees.
Paragraph (b)(1)(ii). A Permit-Required Confined Space (PRCS) is a confined space that has any one of the following: A hazardous atmosphere that ventilation will not reduce to and maintain at a safe level; inwardly-converging, sloping, or tapering surfaces that could trap or asphyxiate an employee; or an engulfment hazard or other physical hazard.
Paragraph (b)(1)(iii). A Controlled-Atmosphere Confined Space (CACS) is a confined space where ventilation alone will control its atmospheric hazards at safe levels. Note also that a confined space cannot be classified as a CACS if it has a physical hazard (unless that hazard has been isolated). The proposed rule includes the CACS as a separate classification from the PRCS because fewer precautions are needed to ensure the safety of its employees than for PRCSs, but more precautions are needed than for an Isolated-Hazard Confined Space (discussed below under paragraph (b)(1)(iv)) because the atmospheric hazard is controlled but not eliminated. This option is provided to the employer to allow it to provide a level of employee protection specifically tailored to, and commensurate with, the hazards within the confined space. In a space properly classified as a CACS, OSHA believes that the use of the CACS measures, as compared with the PRCS measures, would be as protective and typically more cost effective.
Paragraph (b)(1)(iv). An Isolated-Hazard Confined Space (IHCS) is a confined space in which the employer has isolated all physical and atmospheric hazards. “Isolated” means the elimination or removal of a physical or atmospheric hazard by preventing its release into a confined space. Isolation includes, but is not limited to, the following methods: Blanking and blinding; misaligning or removing sections of lines, pipes, or ducts; a double-block-and-bleed system; locking out or tagging out energy sources; machine guarding; and blocking or disconnecting all mechanical linkages. Methods must be implemented to ensure that the hazards remain isolated. Isolation methods provide the highest degree of assurance that the hazard will be kept away from the employees in the space, since it consists of methods that do not depend on the continued, proper operation of machinery (such as ventilation equipment) or personal protective equipment (such as respirators). Consequently, this classification of space presents the lowest hazard level to the employees, and is similar to a “non-permit space” described in 29 CFR 1910.146(c)(7) of the general industry standard.
