Chapter 3
GENERAL REQUIREMENTS
In light of OSHA 29 CFR 1926.(6)(i) "any specific regulations" requirement - essential regulatory requirements are contained in the American National Standards Institute (ANSI) Z117.1, Safety Requirement for Confined Spaces, 29 CFR 1910.146. and National Fire Protection Association (NFPA) standards. With the new OSHA requirement confined spaces under construction are far more regulated than the industry standard.
1. Confined Space Program Responsibility. The General/Prime Contractor is responsible for coordinating the sites confined space program. Each organization having tasks that require entry into confined spaces is primarily responsible for its related portions of the confined space entry program. This responsibility is accomplished in close coordination with the Confined Space Team (see chapter 2).
2. Identification of Confined Spaces. The Site Safety Manager, in coordination with personnel on the CST, will identify, evaluate, and classify each confined space within the organization. If permit-required confined spaces are identified and workers and other employees may enter, the contractor will ensure a written confined space program consistent with the requirements of this standard is implemented. See the Permit-Required Confined Space Decision Flow Chart at Attachment 3 for assistance in classifying confined spaces.
3. Initial Testing and Evaluation of Confined Space Conditions . Contractor safety personnel and entry supervisors, in coordination with the CST, must test for and evaluate many factors prior to classifying a confined or enclosed space. Such evaluations will include, but are not necessarily limited to, the following considerations:
The contents or previous contents of the space that may result in the presence of flammables, toxic materials, or oxygen-deficient or enriched atmospheres.
The location and configuration of the space, including restricted access, obstructions, remote-ness, etc., which may inhibit or interfere with movement, ventilation, rescue efforts, or fire fighting efforts.
Potential hazards from the external environment, such as the proximity of liquid oxygen (LOX) storage operations, petroleum, oil, and lubricants (POL) storage areas, sewer and waste water treatment processes, and underground disposal sites, which could affect the atmosphere within the confined space.
The types of operations that are conducted within the space, particularly those which by the very nature of the process produce toxic materials, flammables, oxygen depletion or enrichment, or ignition sources.
Fixtures, devices, or equipment within the space that may create or contribute to hazardous conditions including piping systems, conduits, ducts, machinery, pressurized lines, etc.
The presence of other hazards such as slippery surfaces, deteriorated or unstable portable ladders, irritant or caustic materials, etc. Pay attention to the condition of permanently-installed ladders, such as those with metal rungs embedded into concrete walls of manholes or other structures.
The boundary spaces and their contents to ensure fire or explosion is not caused in these spaces by the operation being conducted.
Initial testing that shall be performed from outside the space. Testing into the interior of the space may be performed by drop tests or insertion of sample probes and hoses into the space. Testing will be performed in the following sequence:
Oxygen Content. Combustible gases are tested after tests for oxygen content because the threat of fire or explosion is more immediate and more life threatening, in most cases, than exposure to toxic gases and vapors.
Flammable Hazard. Many combustible gas indicators and (or) explosimeters require oxygen for proper operation (generally 10- to 30-percent oxygen by volume). Corrections for known flammable components, if different from the calibration gas, will be made according to the manufacturer's instructions.
Toxic Materials. For the determination of initial confined space classification, chemical substances known or expected to be present shall be measured and evaluated for their potential to produce a hazardous atmosphere (as defined in Attachment 1).
4. Classification of Confined Spaces . Confined spaces are classified on the basis of measurements of the oxygen content, flammability, toxicity by testing (use table 3.1.) and physical hazards. This table is based upon existing or potential confined space hazards. Confined spaces are also classified relative to material contained in the space that could cause engulfment or are configured in a manner that could result in entrapment and (or) asphyxiation. All personnel will assume confined spaces are permit-required until proven otherwise by means of testing and (or) inspection.
Permit-required confined spaces may contain hazards that present a situation that is IDLH or has a potential for or contains a hazardous atmosphere as defined in Attachment 1.
Non-permit confined space contains no hazardous atmosphere. The entrants will not perform any work that could cause a hazardous atmosphere. The space does not have a potential for engulfment and is not configured in a way that would cause entrapment or asphyxiation.
5. Posting Signs . If there are confined spaces designated as permit-required and workers and other employees could inadvertently enter, the supervisor will ensure personnel are informed of the existence, location, and the danger of the permit space by posting danger signs. Use a sign stating "DANGER - PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER" or a commercially available equivalent Confined spaces where personnel cannot inadvertently enter, such as those protected by heavy manhole covers which require special tools to remove, need not be posted.
6. Approved Equipment. Before purchasing equipment to support the confined space entry program, coordinate with the CST. The entry supervisor will ensure testing and monitoring equipment used in confined spaces is approved for use in Class I, Division 1 and the appropriate group atmosphere, as defined in NFPA 70, The National Electrical Code (NEC), Article 500, Hazardous (Classified) Locations. Only direct reading equipment with current calibration will be used. The entry supervisor will also ensure equipment meets required standards of safety as determined by an appropriate Nationally Recognized Testing Laboratory (NRTL) as listed in the OSHA NRTL Program--Underwriters' Laboratories (UL), Factory Mutual Research Corporation (FMRC), etc. Group classifications are provided in NFPA 497M, Manual for Classification of Gases, Vapors, and Dust for Electrical Equipment in Hazardous Locations. Guidance is also provided in National Materials Advisory Board (NMAB) 353-5, Classification of Gases, Liquids, and Volatile Solids Relative to Explosion-Proof Electrical Equipment.
7. Testing of Confined Spaces . Testing, also called verification testing, will be accomplished prior to entry into permit-required confined spaces. This testing will be done by a qualified person who is trained and certified according to guidance in chapter 5. Testing for classification of confined spaces is accomplished by a technically qualified professional member of the CST; normally contractor safety personel.
8. Calibration of Monitoring Equipment. Monitoring equipment used to evaluate confined spaces shall be calibrated usually by the manufacturer, at least annually. Some monitoring equipment (e.g., colorimetric tubes) does not require calibration. Equipment that comes with manufacturer-approved calibration devices and does not require annual calibration is also acceptable.
The user will field check equipment according to the manufacturer's instructions, immediately before testing the confined space. Workers will not use equipment that cannot be calibrated or which fails the field check, until it is repaired and the calibration and (or) field check is successfully accomplished.
9. Atmospheric Monitoring. Many operations may generate hazardous conditions and may require atmospheric monitoring as the work progresses to ensure safe conditions are maintained. The frequency and types of testing are dependent upon prevailing conditions and the nature of the operations. No single rule can be established for all operations and conditions. The entry supervisor, with assistance from the CST, shall establish the frequency and type of tests for atmospheric monitoring and shall enter these requirements on the MEP and the entry permit. The continuous monitoring of oxygen levels, flammable vapor levels, and toxicity levels should be considered for all permit-required confined space operations.
The entry supervisor with appropriate assistance as stated above shall carefully evaluate the following types of operations for continuous atmospheric monitoring:
Work that has the potential of generating hazardous concentrations of toxic materials. (Examples: welding, cutting, brazing, soldering, etc.)
Application of preservatives, paints, epoxies, solvents, etc., which may involve hazardous concentrations of toxic or flammable vapors.
Cleaning operations, sludge removal, etc., which may produce or cause release of hazardous concentrations of toxic or flammable vapors
. Any similar operations that possess the potential for producing or releasing toxic, flammable, or asphyxiating atmospheres or material into the space.
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