Confined space means a space configured so that an employee
can bodily enter and perform assigned work; however, the space
limited or restricted means for entry or exit (for example,
tanks, silos, vessels, storage bins, vaults and pits may
have limited means of entry); and
not designed for continuous employee occupancy.
of engulfment involves the surrounding and effective capture
of a person by a liquid or finely divided (flowable) solid.
Such a material can cause death by suffocation or strangulation.
Many other factors such as air contamination, existing ventilation,
and oxygen deficiency (which is common in grain silos) need
to be taken into consideration for safe operation in a confined
space. An oxygen-deficient atmosphere is one with an oxygen
content of less than 19.5 percent, where an oxygen enriched
atmosphere is one that exceeds 23.5 percent oxygen by volume.
Oxygen enriched atmospheres are particularly hazardous due to
their higher risk of flammability.
All confined spaces require the presence of an attendant who
is stationed outside one or more confined spaces to monitor
the authorized entrants. An authorized entrant means a person
designated by the employer to enter a confined space. A "hot
work permit" is necessary when the permitted employee is performing
duties that require welding, cutting, burning or heating; equipment
used for these tasks is capable of being an ignition source.
Both engulfment and asphyxiation have been critical hazards
particularly in the case of agricultural operations. It is important
to note that there are different standards that pertain to different
types of industry regarding confined spaces.
CCR Title 8. 1910.146 - Permit-required confined spaces (general).
Standard number: 1910.146
Subpart number: J
Subpart title: General environmental
CCR Title 8. Article 109, California Labor Code 5178 (grain
CCR Title 8. Article 109, California Labor Code 5166 (cleaning,
repairing, or altering containers).
Consultation Service: Permit Required Confined Spaces, Employee
National Safety Council (NSC): Confined Space Entry Program.
Basic testing information about testing and entering confined
spaces. Product #14543-2222.
Entrant/Attendant Workbook (NSC).
Guides the entrant/attendant
through class exercises and on-site activities. Product #15968-0000.
Confined Spaces Manual (NSC).
Testing for potential hazards
in confined spaces, protective clothing and equipment. Product
articles and information
Chase, Ellen. "The dangers associated with confined workspaces."
Occupational Safety and Health. May 1996.
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