ANSI Z117.1: Confined Spaces
ANSI/ASSP Z117.1, Safety Requirements for Confined Spaces, is a consensus standard that describes how to find, evaluate and control hazards in confined spaces. It is not an OSHA rule, but it is widely used as good practice and may go beyond OSHA.
- Safety Professionals
- Employers
- Entrants & Attendants
What it covers
- Scope: general industry, construction and other workplaces where people enter confined spaces.
- Definition: a space large enough to enter, with limited means of entry or exit, not designed for continuous occupancy. Similar to OSHA, with its own wording.
- Hazard assessment: identify and evaluate hazards before entry: atmosphere, engulfment, entrapment, mechanical, electrical, thermal and others.
- Entry program: written procedures, permits, roles and duties, training and records.
- Atmospheric testing and monitoring, ventilation and isolation of energy and materials.
- Rescue: planning for rescue before entry, including trained teams and equipment. See Confined Space Rescue.
- Contractors and multi-employer coordination.
How it relates to OSHA
- OSHA's rules are in 1910.146 (general industry) and 1926 Subpart AA (construction). They are legally enforceable. See Confined Spaces.
- Z117.1 adds detail, such as the importance of hazard evaluation by qualified people and rescue planning. OSHA may cite the General Duty Clause and refer to consensus standards as evidence of recognized good practice.
- Where Z117.1 and OSHA differ, an employer must at least meet OSHA's rule, and may choose the stricter approach.
Roles
- Entrant: enters and knows the hazards, signs of exposure and how to leave.
- Attendant: stays outside, monitors the entrants and calls for rescue, never entering.
- Entry supervisor: authorizes entry and checks conditions.
Using the standard
- Get the current edition of ANSI/ASSP Z117.1 from the publisher
- Compare it with your written program and OSHA rules
- Fill gaps, such as hazard evaluation or rescue drills
- Train entrants, attendants and supervisors
- Review permits and near misses to improve
Standards & references
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