§ 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 equipment in-	1	Area within 5 feet of any edge of such equip-
stalled in accordance with		ment, extending in all directions.
5546(d) where flammable
vapor-air mixtures may ex-
ist 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. [FNa1]
Outdoor equipment of the	1	Area within 3 feet of any edge of such equip-
type covered in 5546(d)		ment, extending in all directions.
where flammable vapor-
air mixtures may exist un-
der 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 Roof and	2	Within 10 feet from shell, ends or roof of
		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 Filling	1	Within 3 feet of vent and fill opening, ex
Outdoors, or Indoors		tending in all directions
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 Vent-	2	Entire area within pit if any part is within a
lation		Division 1 or 2 classified area.
Containing Valves, Fit-	2	Entire pit.
tings or Piping, and Not
Within a Division 1 or 2
Classified Area
Drainage Ditches, Separ-	2	Area up to 18 inches above ditch, separ-
ators, Impounding Basins		ator, or basin. Also up to 18 inches above
		grade within 15 feet horizontally from any
		edge.

[FNa1] 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.

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).

Note

Note: Authority cited: Section 142.3, Labor Code.