OSHA Hazard Information Bulletins1
Attaching an Unguarded Blowtorch Regulator to a Portable Propane Cylinder

October 7, 1996




  • Acting Director
  • Directorate of Technical Support


  • Hazard Information Bulletin1 - Attaching an Unguarded Blowtorch Regulator to a Portable Propane Cylinder

The Denver Regional Office brought to our attention a fatal accident involving a 20-pound propane cylinder regulator that broke off when the cylinder fell. The regulator was vulnerable to this kind of damage because it protruded past the cylinder's protective collar. The use of unguarded regulators on propane cylinders appears to be a common practice found on construction sites.

A construction worker who did not receive job-related training entered a manhole with a 20-pound Department of Transportation (DOT) approved propane cylinder with a "Big Bertha" blowtorch assembly attached. While attempting to melt ice in the manhole, the employee placed the cylinder on a step of a portable ladder. The cylinder fell from the ladder and the regulator hit the floor of the manhole. The regulator broke free from the cylinder's main valve assembly, releasing gas and liquid propane into the manhole. The gas in the manhole ignited, resulting in a fire that caused the worker's death.

A regulator that protrudes past a portable cylinder's protective collar (as shown in the attached illustration) can create a hazardous condition. In this instance, paragraph (h) of the Occupational Safety and Health Administration (OSHA) standard 29 CFR 1926.153, which addresses liquefied petroleum (LP) gas containers and equipment used inside of buildings and structures, applies. The standard states that when operational requirements make the use of cylinders outside of buildings and structures impractical these cylinders maybe used inside of buildings and structures if paragraphs (h)(2) through (11) of 29 CFR 1926.153 standards are followed. Title 29 CFR 1926.153(h)(4) states that when regulators are used the regulator must be connected directly to the container valve and paragraph (h)(5) states that valve on containers having a water capacity greater than 50-pounds (normal 20-pounds LP-gas capacity) shall be protected from damage while in use or storage. It should be noted that the pertinent provision for using this equipment installed outside (29 CFR 1926.153(g)) requires that "Containers shall be upright upon firm foundations or otherwise firmly secured". In this instance, the cylinder was not secured nor on a firm foundation, although it was used "inside" (within a confined space). It is recognized that the incident described above happened at a construction site. If a similar incident had occurred at a general industry worksite, 29 CFR 1910.110(c)(5)(a) through (l) would be applicable. Title 29 CFR 1910.110(c)(5)(d) specifically requires that valves on such containers shall be protected.

Recommendations for use by employees and employers involved in similar operations should include the following:

  1. The employee and supervisor should be given training on the recognized and associated hazards for the work that is to be performed.
  2. Training on what equipment is needed for the job and how to use this equipment.
  3. Supervisors should determine that employees are using properly assigned equipment.
  4. Critical parts of equipment shall be protected from danger.

In addition, 20-pound LP-gas cylinders like the one illustrated on attachment one, are addressed under the National Fire Protection Association's (NFPA's) "Standard for the Storage and Handling of Liquefied Petroleum Gases," 58-1995 section 2-2.4.1 "Portable Containers Appurtenance Physical Damage Protection". NFPA recommends that such cylinders incorporate protection against physical damage to appurtenances and immediate connections to those while in transit, storage, while being moved into position for use and when in use, except in permanent residential and commercial installations. Section 2-3.7(b) states that valves, regulators, gauges, and other container appurtenances shall be protected against physical damage. NFPA 58-1995 recommendations for the safe use of cylinders of this type include:

  1. Recessing connections into the container so that valves will not be struck if the container is dropped on a flat surface.
  2. Providing a ventilation cap or collar designed to permit adequate pressure relief valve discharge and capable of withstanding a blow from any direction equivalent to that of a 30-lb.(14-kg) weight dropped 4 ft.(1.2 m). The standard also requires that the construction of the cap collar must be such that the force of a blow will not be transmitted to the valve. In addition, collars must be designed so they do not interfere with the free operation of the cylinder valve.
  3. All persons employed in handling LP-gas shall be trained in proper handling and operating procedures. Such training shall be documented (paragraph 1.5 of NFPA 58-1995).
  4. DOT cylinder specification containers be installed only above ground, and shall be set upon a firm foundation, or otherwise firmly secured (paragraph 3-2.4.1).

OSHA compliance officers and consultation personnel, as well as employers, should be aware that the hazardous condition described above is likely to be found at construction sites. Additionally, they should be aware of the recommended procedures for eliminating this hazard.

Please distribute this bulletin to all Area Offices, State Plan States, Consultation Projects, and appropriate local labor and industrial associations. Copies of this HIB may be used for outreach purposes.

1 The Directorate of Technical support issues Hazard Information Bulletins (HIBs) in accordance with OSHA Instruction CPL 2.65 to provide relevant information regarding unrecognized or misunderstood heath hazards, inadequacies of materials, devices, techniques, and safety engineering controls. HIBs are initiated based on information provided by field staff, studies, reports, and concerns expressed by safety and health professionals, employers, and the public. Information is compiled based on a thorough evaluation of available facts and literature, in coordination with appropriate parties. HIBs are used as an outreach tool for accident prevention.