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Subchapter 7. General Industry Safety Orders
Group 20. Flammable Liquids, Gases and Vapors
Article 139. Oxygen

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§5502. Distance Between Bulk Oxygen Systems and Exposures.

(a) Except as provided in (15), the minimum distance from any bulk oxygen storage container to exposures, measured in the most direct line (except as indicated in (5), shall be as indicated in (1) to (15) inclusive.

(1) 50 feet from buildings of wood frame construction.

(2) Not less than one foot (or other distance to permit system maintenance) from buildings of other than wood frame construction, including fire resistive, heavy timber, noncombustible, and ordinary construction.

(3) At least 10 feet from any opening in walls of adjacent structures. This provision shall apply to all elements of a bulk oxygen system where the oxygen storage is high pressure gas. Where the storage is as liquid, this provision shall apply to only pressure regulators, safety devices, vaporizers, manifolds, and interconnecting piping.

(4) Flammable and Combustible Liquid Storage Aboveground:

Distance (feet)                             Capacity (gallons) 
25                                                1000 or less 
50                                                1001 or more 

(5) Flammable and Combustible Liquid Storage Belowground:

Distance Measured Horizontally         Distance from Oxygen Storage 
from Oxygen Storage Container          Container to Filling and Vent 
      to Tank (feet)               Connections or Openings to Tank (feet) 
            15                                    25 

(6) 25 feet from quantities of flammable gases not exceeding 1,000 gallons of liquefied gases, or 25,000 cubic feet NTP for nonliquefied or dissolved gases. For quantities in excess of these, the distance shall be 50 feet.

(7) 50 feet from solid materials which burn rapidly, such as excelsior or paper.

(8) 25 feet from solid materials which burn slowly, such as coal and heavy timber.

(9) 75 feet in one direction and 35 feet in approximately 90 direction from confining walls (not including fire walls less than 20 feet high) to provide adequate ventilation in courtyards and similar confining areas.

(10) 25 feet from congested areas such as offices, lunchrooms, locker rooms, time clock areas, and similar locations where employees may congregate.

(11) 50 feet from places of public assembly.

(12) 50 feet from areas occupied by nonambulatory patients.

(13) 10 feet from any public sidewalk or parked vehicles.

(14) 5 feet from any line of adjoining property which may be built upon.

(15) The distances in (1), (4) to (8) inclusive, (13), and (14) do not apply where protective structures, such as fire walls or insulated liquid oxygen storage containers, interrupt the line-of-sight between uninsulated portions of the bulk oxygen storage installation and the exposure. In such cases, the uninsulated bulk oxygen installation shall be a minimum distance of 1 foot (or greater distance if required for system maintenance) from the protective structure. (Title 24, Part 6, Section T8-5502)

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Amendment of subsection (a)(15) filed 12-19-78; effective thirtieth day thereafter (Register 79, No. 1).

2. Amendment of subsection (a)(10) filed 9-19-80; effective thirtieth day thereafter (Register 80, No. 38).

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