Confined Space Entry - Construction, Agriculture, and Other Industries

Every year workers die in confined spaces. These deaths typically occur for two reasons:

1. Employers and workers fail to recognize and control the hazards associated with confined spaces, and
2. Inadequate or incorrect emergency response results in the death of the initial entrant, the would-be rescuer, or both.

The Cal/OSHA regulations covering confined space entry for construction, agriculture, and a few other industries can be found in Title 8 of the California Code of Regulations, Section 5158, Other Confined Space Operations. In addition to covering construction and agriculture, Section 5158 also covers marine terminal operations, telecommunication manholes, grain handling facilities, natural gas utility operation within distribution and transmission facility vaults, and electric utility operations within underground vaults. Section 5158 differs significantly from Section 5157, which covers confined space operations for general industry. Section 5156 outlines exactly which industries are covered by Section 5158. Note that shipyard operations are not covered by either 5157 or 5158; they are regulated by Section 8355. Below is a summary of Section 5158.

A confined space, as defined by Section 5158, is a space with the concurrent existence of the following conditions:

• Existing ventilation is insufficient to remove dangerous air contamination, oxygen enrichment, and/or oxygen deficiency which may exist or develop.
• Ready access or egress for the removal of a suddenly disabled employee is difficult due to the location and/or size of the opening(s).

Dangerous air contamination includes any of the following:

• A concentration of flammable gas or vapor that is greater than 20 percent of its lower explosive limit (LEL).
• A concentration of combustible particulate greater than 20 percent of the minimum explosive concentration of the particulate.
• A concentration of a toxic substance that is immediately hazardous to life or health.

Hazardous oxygen levels include either of the following:

• Oxygen deficiency – an atmosphere containing less than 19.5% oxygen.
• Oxygen enrichment – an atmosphere containing more than 23.5% oxygen.

Written operating and rescue procedures that conform to the requirements of the standard must be developed and provided to affected employees. These procedures must include coordinating activities with the operations of other employers both inside and outside the space.

Employees must be trained in the operating and rescue procedures, along with the hazards they may encounter.

Pre-entry procedures must be followed. These procedures must address, as applicable, the following:

• Disconnecting, blinding, or blocking off lines which may convey flammable, injurious, or incapacitating substances.
• Emptying, flushing, and purging the space of flammable, injurious, or incapacitating substances. Testing the air for dangerous air contamination and unacceptable oxygen levels prior to entry and periodically thereafter.
• Ventilating the space.
• The introduction of ignition sources.
• The use of oxygen-consuming equipment.
• Provisions for ready entry and exit.
• Deactivation of automatic fire suppression systems in the space.

Safe entry procedures must be followed if an atmosphere free of dangerous air contaminants, oxygen deficiency, or oxygen enrichment cannot be ensured. These procedures must include, as appropriate:

• Side entry vs. top entry.
• Respiratory protection.
• Safety harnesses and hoists.
• A standby employee outside the space.
• An additional employee outside the space.
• An independent source of breathing air for the standby employee.
• Prohibition of work involving ignition sources.
• Proper use of inerting gases.
• Atmospheric testing.
• The use of approved lighting and electrical equipment.
• Appropriate personal protective equipment (PPE).
• The availability of person(s) trained in first aid and CPR.
• An effective means of communication.

If contractors are hired to enter a space, the host employer must inform the contractor of the hazards of the space and that a confined space program is required for entry into the space. The contractor must be debriefed at the conclusion of entry operations. Joint entries must be coordinated. Entries must also be coordinated with work near the space.

Physical hazards, such as moving parts in mechanical systems, release of stored energy in hydraulic or pneumatic lines, electrical energy, and engulfment by loose materials are not addressed in Section 5158. However, these hazards must also be controlled, and requirements for addressing these other safety issues can be found in other sections of the Cal/OSHA regulations. These sections include, but are not limited to, Section 3314 for lockout/tagout, Section 5178 for grain handling facilities, Sections 2320.1-2320.9 for low-voltage work procedures, Sections 2940-2945 for high-voltage work procedures, and Section 8616 for underground telecommunications lines.

For the complete Cal/OSHA requirements, visit the Department of Industrial Relations Web site.

Related Link

• Department of Industrial Relations

The above evaluations and/or recommendations are for general guidance only and should not be relied upon for legal compliance purposes. They are based solely on the information provided to us and relate only to those conditions specifically discussed. We do not make any warranty, expressed or implied, that your workplace is safe or healthful or that it complies with all laws, regulations or standards.