Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-155 - Safety standards for construction work › Part C - PERSONAL PROTECTIVE AND LIFE SAVING EQUIPMENT › Section 296-155-20301 - Definitions applicable to confined spaces Confined space

Current through Register Vol. 24-14, July 15, 2024
Confined space.
A space that:
(1) Is large enough and so configured that an employee can
				  bodily enter and perform assigned work; and
(2) Has limited or restricted means for entry or exit (for
				  example, tanks, vessels, silos, storage bins, hoppers, vaults, and pits are
				  spaces that may have limited means of entry); and
(3) Is not designed for continuous employee occupancy.
Corrosives
Substances which in contact with
				  living tissue cause destruction of the tissue by chemical action.
Hazardous atmosphere
An atmosphere that may
				  expose employees to the risk of death, inca-pacitation, impairment of ability
				  to self-rescue (that is, escape unaided from a permit space), injury, or acute
				  illness from one or more of the following causes:
(1) Flammable gas, vapor, or mist in excess of 10% of its
				  lower flammable limit (LFL);
(2) Airborne combustible dust at a concentration that meets
				  or exceeds its LFL;
Note:
This concentration may be approximated as a
						  condition in which the dust obscures vision at a distance of 5 feet (1.52m) or
						  less.
(3) Atmospheric oxygen concentration below 19.5 % or above
				  23.5 %;
(4) Atmospheric concentration of any substance for which a
				  dose or a permissible exposure limit is published in chapter 296-62 WAC,
				  general occupational health standards, or chapter 296-841 WAC, Airborne
				  contaminants, and which could result in employee exposure in excess of its dose
				  or permissible exposure limit;
Note:
An atmospheric concentration of any
						  substance that is not capable of causing death, incapacitation, impairment of
						  ability to self-rescue, injury, or acute illness due to its health effects is
						  not covered by this provision.
(5) Any other atmospheric condition that is immediately
				  dangerous to life or health.
Note:
For air contaminants for which WISHA has
						  not determined a dose or permissible exposure limit, other sources of
						  information, such as safety data sheets that comply with the Hazard
						  Communication Standard, WAC
						  296-901-140, published
						  information, and internal documents can provide guidance in establishing
						  acceptable atmospheric conditions.
Irritants
Substances which on immediate,
				  prolonged, or repeated contact with normal living tissue will induce a local
				  inflammatory reaction.
Oxygen deficient atmospheres
Atmospheres at sea
				  level having less than 19.5% oxygen by volume or having a partial pressure of
				  148 millimeters of mercury or less. This may deviate when working at higher
				  altitudes and should be determined for an individual location. Factors such as
				  acclimatization, physical condition of persons involved, etc., must be
				  considered for such circumstances and conditions. (See chapter 296-809 WAC,
				  Confined Spaces.)
Toxicants
Substances which have the inherent
				  capacity to produce personal injury or illness to persons by absorption through
				  any body surface.
Statutory Authority:
					 RCW
					 49.17.010,
					 49.17.040,
					 49.17.050,
					 49.17.060. 07-05-062, §
					 296-155-20301, filed 2/20/07, effective 4/1/07; 05-03-093, §
					 296-155-20301, filed 1/18/05, effective 3/1/05. Statutory Authority:
					 RCW
					 49.17.010,[49.17].040 , and [49.17].050.
					 01-11-038, § 296-155-20301, filed 5/9/01, effective 9/1/01. Statutory
					 Authority:
					 RCW
					 49.17.040, [49.17].050 and [49.17].060.
					 95-17-036, § 296-155-20301, filed 8/9/95, effective 9/25/95. Statutory
					 Authority: Chapter 49.17 RCW. 95-04-007, § 296-155-20301, filed 1/18/95,
					 effective 3/1/95; 91-24-017 (Order 91-07), § 296-155-20301, filed
					 11/22/91, effective 12/24/91. Statutory Authority:
					 RCW
					 49.17.040 and
					 49.17.050. 86-03-074 (Order
					 86-14), § 296-155-20301, filed
					 1/21/86.