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Major Work Activities for Tank Cleaning Operations
The following information provides some of the requirements and additional guidance to employers and employees who participate in activities related to entry into petroleum and petrochemical ground storage tanks.

Preplanning

Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • Recommended Practice 2219, Safe Operating Guidelines for Vacuum Trucks in Petroleum Service. (2005, November).
  • Recommended Practice 2220, Improving Owner and Contractor Safety Performance. (2005, March).
  • Recommended Practice 2221, Contractor and Owner Safety Program Implementation. (2004, August).
  • Publication 2202, Dismantling and Disposing of Steel from Aboveground Leaded Gasoline Storage Tanks. (1991, January).
Tank cleaning operations preplanning must include, but not be limited to, items such as:
  • Engineering, maintenance and operations preplanning including identifying spaces that are permit-required confined spaces.
  • Hazard analysis and elimination, control and/or protection.
  • Confined space program (facility and contractor). For further details on these mandatory requirements, please see:
  • Pre-cleaning site review and survey.
  • Employer/contractor responsibilities.
  • Permit requirements. [1910.146(f)]
  • Degassing and vapor control, collection or dispersal.
  • Product removal and disposal.
  • Equipment and materials.
    • Electrical equipment must be approved for its use and used as listed or labeled. In addition, most tanks must be classified as a hazardous location due to the flammable/combustible materials they contained. In such hazardous locations, equipment must meet additional requirements. [1910.307]
  • Rescue and emergency plans and designated responders. [1910.146(k)]
  • Tank pre-cleaning meeting.
Additional Information

For additional information on general safety and health concerns, see OSHA's Safety and Health Topics Pages on:


Training and Rescue

Worker Training

Before the initial work assignment begins, the employer must provide proper training for all workers who are required to work in permit spaces. After the training, employers must ensure that the employees have acquired the understanding, knowledge and skills necessary to safely perform their duties. Additional training is required when:
  • The job duties change;
  • A change occurs in the permit space program or the permit space operation presents any new hazard; and
  • An employee's job performance shows deficiencies. In addition to this training, rescue team members also require training in CPR and first aid. Employers must certify that this training has been provided.
After completion of training, the employer must keep a record of employee training and make it available for inspection by employees and their authorized representatives. The record must include the employee's name, the trainer's signature or initials and dates of the training.

Assigned Duties

Authorized Entrant

Authorized entrants are required to:
  • Know space hazards, including information on the means of exposure such as inhalation or dermal absorption, signs of symptoms and consequences of the exposure;
  • Use appropriate personal protective equipment properly;
  • Maintain communication with attendants as necessary to enable them to monitor the entrant's status and alert the entrant to evacuate when necessary;
  • Exit from the permit space as soon as possible when:
    • Ordered by the authorized person;
    • He or she recognizes the warning signs or symptoms of exposure;
    • A prohibited condition exists; or
    • An automatic alarm is activated.
  • Alert the attendant when a prohibited condition exists or when warning signs or symptoms of exposure exist.
Emergencies

Rescue Service Personnel

The standard requires employers to ensure that responders are capable of responding to an emergency in a timely manner. Employers must provide rescue service personnel with personal protective and rescue equipment, including respirators, and training in how to use it. Rescue service personnel also must receive the authorized entrants training and be trained to perform assigned rescue duties.

The standard also requires that all rescuers be trained in first aid and CPR. At a minimum, one rescue team member must be currently certified in first aid and CPR. Employers must ensure that practice rescue exercises are performed yearly and that rescue services are provided access to permit spaces so they can practice rescue operations. Rescuers also must be informed of the hazards of the permit space.

Harnesses and Retrieval Lines

Authorized entrants who enter a permit space must wear a chest or full body harness with a retrieval line attached to the center of their backs near shoulder level or above their heads. Wristlets may be used if the employer can demonstrate that the use of a chest or full body harness is not feasible or creates a greater hazard.

Also, the employer must ensure that the other end of the retrieval line is attached to a mechanical device or a fixed point outside the permit space. A mechanical device must be available to retrieve someone from vertical type permit spaces more than five feet (1.524 meters) deep.

MSDS

If an injured entrant is exposed to a substance for which a Material Safety Data Sheet (MSDS) or other similar written information is required to be kept at the worksite, that MSDS or other written information must be made available to the medical facility personnel treating the exposed entrant.

 Additional Information

Removing Recoverable Product from Tanks using Fixed Connections and Piping (Decommissioning)

Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • Recommended Practice 2026, Safe Access/Egress Involving Floating Roofs of Storage Tanks in Petroleum Service. (2006, June).
  • Recommended Practice 2219, Safe Operating Guidelines for Vacuum Trucks in Petroleum Service. (2005, November).
Employers should establish, and tank cleaning entry supervisors should implement, procedures for removing recoverable product from the tank that cover items such as the following:
  • Area protection, potential sources of ignition and electrical classification.
  • Bonding and grounding.
  • Entry onto fixed and floating roofs.
  • Removing recoverable product through product lines.
  • Recoverable product removal by suction pump through fixed connections.
  • Recoverable product removal by flotation through open manholes or connections.
  • Recoverable product removal by vacuum pump.
  • Recoverable product removal through open manholes.

Tank Isolation

Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • Recommended Practice 2003, Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents. American Petroleum Institute (API), (1991, December).
Employers must develop and implement the isolation means, procedures, and practices necessary for safe tank entry. Before entry is made, employers must document the completion of these measures and entry supervisors must verify that all procedures have been followed before endorsing the permit.

"Isolation" means the process by which a permit space is removed from service and completely protected against the release of energy and material into the space by such means as: blanking or blinding; misaligning or removing sections of lines, pipes, or ducts; a double block and bleed system; lockout or tagout of all sources of energy; or blocking or disconnecting all mechanical linkages.

The isolation plan should address:
  • Tank isolation requirements
  • Tank suction and discharge lines
  • Other tank lines, appurtenances and connections
  • Energy sources - electrical, mechanical and pressure
  • Cathodic protection systems
  • Vapor recovery systems
  • Tank foam protection system
  • Tank gauging and overfill protection alarm system
  • Interior devices such as mixers, etc.
  • Verification of isolation prior to issuing permits

Vapor and Gas Freeing the Tank (Degassing)

Vapor and gas freeing occurs after all product, tank bottoms and residue has been removed from a tank and the tank has been properly isolated. Employers must establish and implement safe vapor and gas freeing procedures. Acceptable entry conditions must be specified and verified through appropriate testing and monitoring, prior to tank entry.

Procedures should include:
  • Vapor and gas freeing (degassing) methods
  • Identification and control of ignition sources including bonding and grounding
  • Elimination and/or control of toxic hazards including, but not limited to, H2S, nitrogen, pyrophorics, CO2, etc.
  • Blower and educator selection and location
  • Requirements for vapor and gas freeing (degassing) the tank
  • Collection, control or dispersal of vapors and gas
  • Purging, inerting, flushing, or ventilating the tanks as necessary to eliminate or control atmospheric hazards.
Additional Information
  • Exposure to Hazards Associated with Temporary Enclosures. OSHA Safety and Health Information Bulletin, (2002, May 30), 31 KB PDF, 4 pages.
  • Hazards of Nitrogen Asphyxiation. U.S. Chemical Safety and Hazard Investigation Board, Safety Bulletin, (2003, June), 218 KB PDF, 10 pages. Provides additional attention to the continuing hazards of nitrogen asphyxiation.
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.

Atmospheric Testing the Tank Interior

The employer must specify acceptable entry conditions and verify that the conditions in the tank are acceptable for entry throughout entry. [1910.146(d)(5)] In addition, conditions around, on top of and below may need to be monitored to assure that safe levels exist.

The testing procedures should include:
  • Testing requirements
  • Testing limitations
  • Testing order [1910.146(d)(5)(iii)]
  • Testing inert atmospheres
  • Test criteria and analysis of results
  • Required personal protective equipment (PPE)
Additional Information
  • Personal Protective Equipment
    • Eye Safety. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
    • Hearing Loss Prevention. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic. Provides references for noise solutions in the workplace.
    • Heat Stress. OSHA Fact Sheet, (2005), 23 KB PDF, 2 pages.
    • Heat Stress. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.  
    • Personal Protective Equipment. OSHA Fact Sheet, (2002), 287 KB PDF, 2 pages. A 68 KB PDF (Spanish version) is also available. 
    • OSHA Technical Manual (OTM). OSHA Directive TED 01-00-015 [TED 1-0.15A], (1999, January 20).
    • Noise and Hearing Conservation. OSHA eTool. A chapter of the OTM developed to assist OSHA staff in evaluating workplace hazards.
    • Respirators. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.

Cleaning the Tank

Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • STD 2015, Safe Entry and Cleaning of Petroleum Storage Tanks. (2001, August).
  • Recommended Practice 2016, Guidelines and Procedures for Entering and Cleaning Petroleum Storage Tanks, First Edition. (2001, August).
  • Recommended Practice 2219, Safe Operating Guidelines for Vacuum Trucks in Petroleum Service. (2005, November).
  • Publication 2217A, Guidelines for Work in Inert Confined Spaces in the Petroleum Industry. (2005, January).
Steel Tank Institute (STI) and Steel Plate Fabricators Association (SPFA)
  • Publication 04-03 Tank Builders Scaffold Guidelines (English).
  • Publication 04-04 Tank Builders Scaffold Guidelines (Spanish).
Tank cleaning entry supervisors must determine, administer and implement safe work procedures and appropriate safe limits for employee's exposure to hydrocarbon vapors and gases and toxic gases, and required oxygen concentrations both when working outside of tanks and when entering and working in tanks during tank cleaning operations, in accordance with applicable regulations and facility confined space entry requirements.

The safe work procedures should include:
  • Permit requirements
  • Personal protective equipment
  • Sludge and residue removal from outside the tank
  • Cleaning the tanks from the inside
Additional Information
  • Falls. OSHA Fact Sheet, 353 KB PDF, 2 pages.
  • Falls from Elevation. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.  
  • Lockout/Tagout. OSHA Fact Sheet, (2002), 212 KB PDF, 2 pages. A 355 KB PDF (Spanish version) is also available.
  • Personal Protective Equipment
    • Eye Safety. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
    • Hearing Loss Prevention. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic. Provides references for noise solutions in the workplace.
    • Heat Stress. OSHA Fact Sheet, (2005), 23 KB PDF, 2 pages.
    • Heat Stress. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.  
    • Personal Protective Equipment. OSHA Fact Sheet, (2002), 287 KB PDF, 2 pages. A 68 KB PDF (Spanish version) is also available. 
    • OSHA Technical Manual (OTM). OSHA Directive TED 01-00-015 [TED 1-0.15A], (1999, January 20).
    • Noise and Hearing Conservation. OSHA eTool. A chapter of the OTM developed to assist OSHA staff in evaluating workplace hazards.
    • Respirators. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.

Working Inside and Around the Tank
Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • STD 2015, Safe Entry and Cleaning of Petroleum Storage Tanks. (2001, August).
  • Recommended Practice 2009, Safe Welding and Cutting Practices in Refineries, Gasoline Plants, and Petrochemical Plants, Seventh Edition. (2002, February).
  • Recommended Practice 2027, Ignition Hazards Involved in Abrasive Blasting of Atmospheric Storage Tanks in Hydrocarbon Service. (2002, March).
  • Publication 2207, Preparing Tank Bottoms for Hot Work. (1998, September).
Steel Tank Institute (STI) and Steel Plate Fabricators Association (SPFA)
  • Publication 04-01 Basic Safety Rules for Fabrication, Field Erection, and Warehousing (English).
  • Publication 04-02 Basic Safety Rules for Fabrication, Field Erection, and Warehousing (Spanish)

Safe work procedures for working inside and around a tank should address:
  • Permit requirements
  • Ventilation
  • Hot work

OSHA Requirements

  • 1910.252, Welding, Cutting, and Brazing, general requirements.
    • (a), Fire prevention and protection.
    • (b)(4), Protection of personnel, work in confined spaces.
    • (c)(4), Health protection and ventilation, ventilation in confined spaces.
Additional Information
  • Falls. OSHA Fact Sheet, 353 KB PDF, 2 pages.
  • Falls from Elevation. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.  
  • Hot Work - Welding. Oil and Gas Well Drilling and Servicing eTool.
  • Lockout/Tagout. OSHA Fact Sheet, (2002), 212 KB PDF, 2 pages. A 355 KB PDF (Spanish version) is also available.
  • Personal Protective Equipment
    • Eye Safety. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
    • Hearing Loss Prevention. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic. Provides references for noise solutions in the workplace.
    • Heat Stress. OSHA Fact Sheet, (2005), 23 KB PDF, 2 pages.
    • Heat Stress. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.  
    • Personal Protective Equipment. OSHA Fact Sheet, (2002), 287 KB PDF, 2 pages. A 68 KB PDF (Spanish version) is also available. 
    • OSHA Technical Manual (OTM). OSHA Directive TED 01-00-015 [TED 1-0.15A], (1999, January 20).
    • Noise and Hearing Conservation. OSHA eTool. A chapter of the OTM developed to assist OSHA staff in evaluating workplace hazards.
    • Respirators. National Institute for Occupational Safety and Health (NIOSH) Safety and Health Topic.
For additional information on general safety and health concerns, see OSHA's Safety and Health Topics Pages on:
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.  

De-isolation and Returning the Tank to Service

Prior to returning a tank to service, employers should develop, and tank cleaning entry supervisors should implement, procedures for tank inspection and preparation, including the following:
  • Inspection (interior and exterior)
  • De-isolation
  • Permits
  • Preparation
Additional Information
  • After Katrina: Precautions Needed During Oil and Chemical Facility Startup. U.S. Chemical Safety and Hazard Investigation Board, Safety Bulletin, (2005, September), 105 KB PDF, 2 pages. Provides attention to the hazards of oil and chemical facility startup.
    •  
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.

Recommissioning

Industry Standards and Recommendations
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.

American Petroleum Institute
  • Recommended Practice 2026, Safe Access/Egress Involving Floating Roofs of Storage Tanks in Petroleum Service. (2006, June).
Tank cleaning entry supervisors should be aware of the requirements to conduct a thorough formal safety check, inside and outside the tank, prior to recommissioning a tank, using a written checklist signed by qualified persons. Employers should develop procedures and assign responsibilities for recommissioning tanks following tank cleaning operations and after conducting a tank recommissioning safety check. If it is necessary to enter the tank to conduct the safety check, entry must be conducted under the permit-required confined spaces standard (1910.146).

Procedures should address:
  • Refilling
  • Atmospheric hazards
  • Static hazards associated with tank refilling, gauging and sampling
  • Entry onto floating roofs and fixed roofs
  • Precautions and requirements
Additional Information
  • After Katrina: Precautions Needed During Oil and Chemical Facility Startup. U.S. Chemical Safety and Hazard Investigation Board, Safety Bulletin, (2005, September), 105 KB PDF, 2 pages. Provides attention to the hazards of oil and chemical facility startup.
    •  
Accessibility Assistance: Contact the OSHA Directorate of Cooperative and State Programs at 202-693-2200 for assistance accessing OSHA PDF materials.
 
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