OAR 437-002-2304
Enclosed Spaces


This rule covers enclosed spaces that may be entered by employees. It does not apply to vented vaults if the employer makes a determination that the ventilation system is operating to protect employees before they enter the space. This rule applies to routine entry into enclosed spaces in lieu of the confined space entry requirements contained in 437-002-0146 (Confined Spaces) (4) through (11). If, after the employer takes the precautions given in 437-002-2304 (Enclosed Spaces) and 437-002-2319 (Underground Electrical Installations) of Division 2/RR, the hazards remaining in the enclosed space endanger the life of an entrant or could interfere with an entrant’s escape from the space, then entry into the enclosed space must meet the permit-space entry requirements of 437-002-0146 (Confined Spaces) (4) through (11), Confined spaces, in Division 2/J.

(1)

Safe work practices. The employer must ensure the use of safe work practices for entry into, and work in, enclosed spaces and for rescue of employees from such spaces.

(2)

Training. Each employee who enters an enclosed space or who serves as an attendant must be trained in the hazards of enclosed-space entry, in enclosed-space entry procedures, and in enclosed-space rescue procedures.

(3)

Rescue equipment. Employers must provide equipment to ensure the prompt and safe rescue of employees from the enclosed space.

(4)

Evaluating potential hazards. Before any entrance cover to an enclosed space is removed, the employer must determine whether it is safe to do so by checking for the presence of any atmospheric pressure or temperature differences and by evaluating whether there might be a hazardous atmosphere in the space. Any conditions making it unsafe to remove the cover must be eliminated before the cover is removed.
NOTE to paragraph (4): The determination called for in this paragraph may consist of a check of the conditions that might foreseeably be in the enclosed space. For example, the cover could be checked to see if it is hot and, if it is fastened in place, could be loosened gradually to release any residual pressure. An evaluation also needs to be made of whether conditions at the site could cause a hazardous atmosphere, such as an oxygen-deficient or flammable atmosphere, to develop within the space.

(5)

Removing covers. When covers are removed from enclosed spaces, the opening must be promptly guarded by a railing, temporary cover, or other barrier designed to prevent an accidental fall through the opening and to protect employees working in the space from objects entering the space.

(6)

Hazardous atmosphere. Employees may not enter any enclosed space while it contains a hazardous atmosphere, unless the entry conforms to the confined space standard, 437-002-0146 (Confined Spaces) Confined spaces, in Division 2/J.

(7)

Attendants. While work is being performed in the enclosed space, an attendant with first-aid training must be immediately available outside the enclosed space to provide assistance if a hazard exists because of traffic patterns in the area of the opening used for entry. The attendant is not precluded from performing other duties outside the enclosed space if these duties do not distract the attendant from: monitoring employees within the space or ensuring that it is safe for employees to enter and exit the space.
NOTE to paragraph (7): See 437-002-2319 (Underground Electrical Installations) Underground electrical installations, for additional requirements on attendants for work in manholes and vaults.

(8)

Calibration of test instruments. Test instruments used to monitor atmospheres in enclosed spaces must be kept in calibration and must have a minimum accuracy of ±10 percent.

(9)

Testing for oxygen deficiency. Before an employee enters an enclosed space, the atmosphere in the enclosed space must be tested for oxygen deficiency with a direct-reading meter or similar instrument, capable of collection and immediate analysis of data samples without the need for offsite evaluation. If continuous forced-air ventilation is provided, testing is not required provided that the procedures used ensure that employees are not exposed to the hazards posed by oxygen deficiency.

(10)

Testing for flammable gases and vapors. Before an employee enters an enclosed space, the internal atmosphere must be tested for flammable gases and vapors with a direct-reading meter or similar instrument capable of collection and immediate analysis of data samples without the need for off-site evaluation. This test must be performed after the oxygen testing and ventilation required by paragraph (9) of this rule demonstrate that there is sufficient oxygen to ensure the accuracy of the test for flammability.

(11)

Ventilation and monitoring for flammable gases or vapors. If flammable gases or vapors are detected or if an oxygen deficiency is found, forced-air ventilation must be used to maintain oxygen at a safe level and to prevent a hazardous concentration of flammable gases and vapors from accumulating. A continuous monitoring program to ensure that no increase in flammable gas or vapor concentration above safe levels occurs may be followed in lieu of ventilation if flammable gases or vapors are initially detected at safe levels.
NOTE to paragraph (11): See the definition of “hazardous atmosphere” for guidance in determining whether a specific concentration of a substance is hazardous.

(12)

Specific ventilation requirements. If continuous forced-air ventilation is used, it must begin before entry is made and must be maintained long enough for the employer to be able to demonstrate that a safe atmosphere exists before employees are allowed to enter the work area. The forced-air ventilation must be so directed as to ventilate the immediate area where employees are present within the enclosed space and must continue until all employees leave the enclosed space.

(13)

Air supply. The air supply for the continuous forced-air ventilation must be from a clean source and may not increase the hazards in the enclosed space.

(14)

Open flames. If open flames are used in enclosed spaces, a test for flammable gases and vapors must be made immediately before the open flame device is used and at least once per hour while the device is used in the space. Testing must be conducted more frequently if conditions present in the enclosed space indicate that once per hour is insufficient to detect hazardous accumulations of flammable gases or vapors.
NOTE to paragraph (14): See the definition of “hazardous atmosphere” for guidance in determining whether a specific concentration of a substance is hazardous.
NOTE to 437-002-2304 (Enclosed Spaces) : Entries into enclosed spaces conducted in accordance with the requirements of 437-002-0146 (Confined Spaces) (4) through (11), Confined spaces, are considered as complying with 437-002-2304 (Enclosed Spaces) of Division 2/RR.
437–002–0005
Adoption by Reference
437–002–0006
General Oregon Definitions
437–002–0007
Testing and Certification
437–002–0010
Adoption by Reference
437–002–0015
Adoption by Reference
437–002–0020
Adoption by Reference
437–002–0022
Additional Oregon General Requirements
437–002–0026
Portable Ladders
437–002–0032
Ramps and Runways
437–002–0033
Piers and Wharves
437–002–0040
Adoption by Reference
437–002–0041
Exits and Exit Routes
437–002–0042
Emergency Action Plan
437–002–0043
Fire Prevention Plan
437–002–0047
Working Near Overhead High Voltage Lines and Equipment
437–002–0060
Adoption by Reference
437–002–0080
Adoption by Reference
437–002–0081
Oregon Ventilation Regulations
437–002–0095
Audiometric Testing in Oregon
437–002–0098
Additional Applicability
437–002–0100
Adoption by Reference
437–002–0101
Oregon Start-Up Dates
437–002–0107
Spray Finishing
437–002–0109
Explosives and Blasting Agents
437–002–0118
Oregon Rules for Reinforced Plastics Manufacturing
437–002–0119
Oregon Effective Dates
437–002–0120
Adoption by Reference
437–002–0122
Dipping and Coating
437–002–0134
Personal Protective Equipment
437–002–0139
Working Underway on Water.
437–002–0140
Adoption by Reference
437–002–0141
Additional Oregon Sanitation Requirements
437–002–0142
Labor Camps
437–002–0144
Additional Oregon Rules for General Environmental Controls
437–002–0145
Additional Oregon Rules for Accident Prevention and Tags
437–002–0146
Confined Spaces
437–002–0154
Individual Locks
437–002–0161
Medical Services and First Aid
437–002–0170
Worker Protection Standard
437–002–0180
Adoption by Reference
437–002–0182
Oregon Rules for Fire Fighters
437–002–0187
Portable Fire Extinguishers
437–002–0200
Adoption by Reference
437–002–0210
Additional Oregon Rules for Compressed Air and Compressed Gas Equipment
437–002–0220
Adoption by Reference
437–002–0221
Additional Oregon Rules for Handling Materials
437–002–0223
Oregon Rules for Commercial and Industrial Vehicles
437–002–0227
Additional Oregon Rules for Powered Industrial Trucks
437–002–0228
Oregon General Requirements for Cranes
437–002–0229
Additional Oregon Rules for Overhead and Gantry Cranes
437–002–0230
Additional Oregon Rule for Crawler, Locomotive and Truck Cranes
437–002–0232
Additional Oregon Rule for Derricks
437–002–0233
Oregon Rules for Hammerhead Cranes
437–002–0235
Additional Oregon Rule for Slings
437–002–0240
Adoption by Reference
437–002–0242
Oregon Rules for Machinery and Machine Guarding
437–002–0256
Stationary Compactors, Self-Contained Compactors, and Balers
437–002–0260
Adoption by Reference
437–002–0262
Additional Definitions in Oregon
437–002–0264
Additional General Requirements for Hand Tools
437–002–0266
Additional Oregon Rules for Guarding Portable Powered Tools
437–002–0268
Oregon Rules for Hand-Powered Equipment
437–002–0280
Adoption by Reference
437–002–0282
Job Planning and Layout
437–002–0283
Eye Protection and Protective Clothing
437–002–0284
Specifications for Protectors
437–002–0285
Special Precautions
437–002–0286
Preservative Coatings
437–002–0287
Toxic Preservative Coatings
437–002–0288
Health Protection and Ventilation — General
437–002–0297
Welding or Cutting Containers
437–002–0298
Self-Contained Units
437–002–0300
Adoption by Reference
437–002–0301
Scope and Application
437–002–0302
Definitions
437–002–0303
Training and Work Planning
437–002–0304
First Aid Requirements
437–002–0305
Traffic Control
437–002–0306
Electrical Hazards
437–002–0307
Personal Protective Equipment
437–002–0308
Portable Power Tools
437–002–0309
Hand Tools
437–002–0310
Work Procedures
437–002–0311
Mobile Equipment
437–002–0312
Oregon Rules for Pulp, Paper and Paperboard Mills
437–002–0313
Additional Oregon Rules for Sawmills
437–002–0314
Veneer and Plywood Machinery
437–002–0315
Shake and Shingle Machinery
437–002–0316
Oregon Rules for Telecommunications
437–002–0320
Adoption by Reference.
437–002–0340
Adoption by Reference
437–002–0342
Additional Oregon Definition
437–002–0345
Inland Emergency Aid
437–002–0355
Air Supply Systems (Compressed Gases and Air)
437–002–0360
Adoption by Reference
437–002–0363
Oregon Amendment
437–002–0364
Oregon Rules for MOCA (4,4’-Methylene Bis (2-chloroaniline))
437–002–0368
Deterioration
437–002–0371
Scope and Application
437–002–0373
Oregon Rules for Thiram
437–002–0377
Additional Oregon Rules for Hazard Communication
437–002–0378
Oregon Rules for Pipe Labelling
437–002–0382
Oregon Rules for Air Contaminants
437–002–0390
Oregon Effective Dates
437–002–0391
Additional Oregon Rules for Carcinogens in Laboratories
437–002–1001
Asbestos Respiratory Protection Program
437–002–1017
Vinyl Chloride Respiratory Protection Program
437–002–1018
Inorganic Arsenic Respiratory Protection Program
437–002–1025
Lead Respiratory Protection Program
437–002–1027
Cadmium Respiratory Protection Program
437–002–1028
Benzene Respiratory Protection Program
437–002–1029
Coke Oven Emissions Respiratory Protection Program
437–002–1030
Additional Oregon Rules for Bloodborne Pathogens
437–002–1035
Oregon Rule for Sharps Injury Log
437–002–1043
Cotton Dust Respiratory Protection Program
437–002–1044
1,2-Dibromo-3-Chloropropane Respiratory Protection Program
437–002–1045
Acrylonitrile Respiratory Protection Program
437–002–1047
Ethylene Oxide Respiratory Protection Program
437–002–1048
Formaldehyde Respiratory Protection Program
437–002–1050
Methylenedianiline Respiratory Protection Program
437–002–1051
1,3-Butadiene Respiratory Protection Program
437–002–1052
Methylene Chloride Respiratory Protection Program
437–002–1053
Scope and Application
437–002–1054
Definitions
437–002–1055
Permissible Exposure Limit (PEL)
437–002–1056
Exposure Assessment
437–002–1057
Specified exposure control methods
437–002–1058
Regulated and Restricted Access Areas
437–002–1059
Methods of Compliance
437–002–1060
Respiratory Protection
437–002–1061
Housekeeping
437–002–1062
Medical Surveillance
437–002–1063
Communication of Respirable Crystalline Silica Hazards to Employees
437–002–1064
Recordkeeping
437–002–1065
Dates
437–002–1139
Working Over or In Water
437–002–2021
Additional Oregon Definitions
437–002–2022
Additional Oregon Rules for Powered Platforms
437–002–2024
Scope and Application
437–002–2025
Definitions
437–002–2026
Permissible Exposure Limit (PEL)
437–002–2027
Rope Descent & Rope Access Systems
437–002–2028
Regulated and Restricted Access Areas
437–002–2029
Methods of Compliance
437–002–2030
Respiratory Protection
437–002–2031
Delayed Effective Dates for Walking-Working Surfaces
437–002–2032
Hygiene Areas and Practices
437–002–2033
Housekeeping
437–002–2034
Medical Surveillance
437–002–2035
Medical Removal
437–002–2036
Communication of Beryllium Hazards to Employees
437–002–2037
Recordkeeping
437–002–2038
Dates
437–002–2040
Exposure Assessment
437–002–2045
Personal Protective Clothing and Equipment
437–002–2101
Compressed Gases (General Requirements)
437–002–2102
Acetylene
437–002–2224
Vehicle Drivers and Riders
437–002–2225
Vehicles for Highway and Road Operation Characteristics and Maintenance
437–002–2226
Vehicles for Use on Property Other Than Public Roads and Highways Operation, Characteristics and Maintenance
437–002–2253
Oxygen-fuel Gas Welding and Cutting
437–002–2300
General
437–002–2301
Medical Services and First Aid
437–002–2302
Job Briefing
437–002–2303
Hazardous Energy Control Procedures
437–002–2304
Enclosed Spaces
437–002–2305
Excavations
437–002–2306
Personal Protective Equipment
437–002–2307
Portable Ladders and Platforms
437–002–2308
Hand and Portable Power Equipment
437–002–2309
Live-line Tools
437–002–2310
Materials Handling and Storage
437–002–2311
Working On or Near Exposed Energized Parts
437–002–2312
Deenergizing Lines and Equipment for Employee Protection
437–002–2313
Grounding for the Protection of Employees
437–002–2314
Testing and Test Facilities
437–002–2315
Mechanical Equipment
437–002–2316
Overhead Lines
437–002–2317
Line-clearance Tree Trimming
437–002–2318
Communication Facilities
437–002–2319
Underground Electrical Installations
437–002–2320
Substations
437–002–2321
Power Generation Installations
437–002–2322
Special Conditions
437–002–2323
Helicopters
437–002–2324
Definitions
Last Updated

Jun. 8, 2021

Rule 437-002-2304’s source at or​.us