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.

Source: Rule 437-002-2304 — Enclosed Spaces, https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=437-002-2304.

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