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Subchapter 7. General Industry Safety Orders
Group 20. Flammable Liquids, Gases and Vapors
Article 140. Electrical Equipment

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§5530. Scope.

This article shall apply to areas where Class I liquids are stored or handled or where Class II or Class III liquids are stored or handled at a temperature above their flash points.

For areas where Class II or Class III liquids only are stored or handled at a temperature below their flash points, the electrical equipment may be installed in accordance with the provisions of the California Electrical Safety Orders for ordinary locations; however, care shall be used in locating electrical apparatus to prevent hot metal from falling into open equipment.

(a) All electrical equipment and wiring shall be of a type specified by and shall be installed in accordance with the California Electrical Safety Orders.

(b) In the application of classified areas, a classified area shall not extend beyond an unpierced floor, wall, roof or other solid partition.

(c) Where the provisions of this article require the installation of electrical equipment suitable for Class I, Division 1 or Division 2 locations, ordinary electrical equipment including switchgear may be used if installed in a room or enclosure which is maintained under positive pressure with respect to the classified area. Ventilation make-up air shall be uncontaminated by flammable vapors.

(1) Pressurizing or purging of classified areas shall be in compliance with NFPA 496-1974.

(d) The area classifications listed in Table FL-1 are based on the premise that the installation meets the applicable requirements of this section in all respects.

(e) Extent of classified areas shall be as contained in Table FL-1. (Title 24, T8-5530)


                       Table FL-1 

                Class I            Extent of 
Location        Division         Classified Area 
Indoors             1    Area within 5 feet of any edge of such equip- 
equipment                ment, extending in all directions. 
installed in
accordance with
5546(d) where
flammable vapor-
air mixtures may
exist under normal
operations. 
                      2   Area between 5 feet and 8 feet of any edge of  
                          such equipment, extending in all directions.  
                          Also, area up to 3 feet above floor or grade  
                          level within 5 feet to 25 feet horizontally  
                          from any edge of such equipment.* 
Outdoor equipment     1   Area within 3 feet of any edge of such equip- 
of thetype covered in     ment, extending in all directions. 
5546(d) where flammable
vapor-air mixtures
may exist under normal
operations. 
                      2   Area between 3 feet and 8 feet of any edge of 
                          such equipment extending in all directions. 
                          Also, area up to 3 feet above floor or grade 
                          level within 3 feet to 10 feet horizontally 
                          from any edge of such equipment. 
Tank--Aboveground (Un- 
derground, see 5574) 
  Shell, Ends, or     2   Within 10 feet from shell, ends or roof of 
  Roof and                tank 
                          
  Dike Area               Area inside dikes to level of top of dike. 
  Vent                1   Within 5 feet of open end of vent, extending 
                          in all directions. 
  Floating Roof       1   Area above the roof and within the shell. 

Drum and Container    1   Within 3 feet of vent and fill opening, ex 
Filling Outdoors,         tending in all directions 
or Indoors with
Adequate Ventilation 
                      2   Area between 3 feet and 5 feet from vent or 
                          fill opening, extending in all directions. Also 
                          up to 18 inches above floor or grade level 
                          within a horizontal radius of 10 feet from 
                          vent or fill opening. 
Pumps, Bleeders, With- 
drawal, Fittings,
Meters and Similar
Devices 
  Indoors             2   Within 5 feet of any edge of such devices ex- 
                          tending in all directions. Also up to 3 feet 
                          above floor or grade level within 25 feet hor- 
                          izontally from any edge of such devices. 

Outdoors              2   Within 3 feet of any edge of such devices, 
                          extending in all directions. Also up to 18 
                          inches above grade level within 10 feet ho- 
                          rizontally from any edge of such devices. 

Pits 
  Without Mechanical  1   Entire area within pit if any part is within a 
  Ventilation             within a Division 1 or 2 classified area. 
  With Mechanical     2   Entire area within pit if any part is within a 
  Ventilation             Division 1 or 2 classified area. 
  Containing Valves,  2   Entire pit. 
  Fittings or Piping,
  and Not Within a
  Division 1 or 2 
  Classified Area 
  Drainage Ditches,   2   Area up to 18 inches above ditch, separ- 
  Separators, or          basin. Also up to 18 inches above grade
  Impounding Basins       within 15 feet horizontally from any edge. 

* The release of Class I liquids may generate vapors to the extent that the entire building, and possibly a zone surrounding it, should be considered a Class I, Division 2 location.

NOTE: Authority cited: Section 142.3, Labor Code.

HISTORY

1. Articles 140-148 (Sections 5530-5629, not consecutive) filed 11-28-75; effective thirtieth day thereafter (Register 75, No. 48).

2. Amendments filed 7-16-76; effective thirtieth day thereafter (Register 76, No. 29).

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