This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at

Subchapter 7. General Industry Safety Orders
Group 10. Gas Systems for Welding and Cutting
Article 84. Calcium Carbide

Return to index
New query

§4818. Storage.

(a) Calcium carbide shall be stored in sealed metal containers which are free from punctures, excessive rusting, corrosion or any other damage that might affect their water and air tightness. The contents of damaged containers shall be promptly used or transferred to another container.

(1) The containers shall be provided with a screw top or equivalent. Solder shall not be used in such a manner that the container would fail if exposed to fire.

(2) Containers containing calcium carbide shall be conspicuously marked "Calcium Carbide Dangerous If Not Kept Dry" or with equivalent warning.

(b) Calcium carbide in quantities up to 600 pounds may be stored in sealed metal containers inside buildings in a dry, waterproof, well ventilated place. The seal shall not be broken so long as there is carbide in excess of one pound in any other unsealed package of that size of carbide in the building.

(1) Calcium carbide exceeding 600 pounds but not exceeding 5,000 pounds shall be stored:

(A) In an inside generator room or outside generator house; or

(B) In a separate room in a one-story building which may contain other occupancies, but without cellar or basement beneath the carbide storage section. Such rooms shall be constructed in accordance with Section 4805 and ventilated in accordance with Section 4807. These rooms shall be used for no other purpose.

(2) Calcium carbide in excess of 5,000 pounds shall be stored in one-story buildings without cellar or basement and used for no other purpose, or in outside generator houses. If the storage building is of noncombustible construction, it may adjoin other one-story buildings if separated therefrom by unpierced firewalls; if it is detached less than 10 feet from such building or buildings, there shall be no opening in any of the mutually exposing sides of such buildings within 10 feet of each other. If the storage building is of combustible construction, it shall be at least 20 feet from any other one- or two-story building, and at least 30 feet from any other building exceeding two stories.

(3) Sprinkler systems shall not be installed in carbide storage rooms.

(c) Calcium carbide in sealed metal containers stored out-of-doors shall be on wooden planking or its equivalent so that the containers will not contact the ground or ground water. The containers shall be stored in rows with ample space for easy inspection and under tarpaulins.

(1) Carbide containers to be stored outdoors shall be examined to make sure that they are in good condition. Periodic reexaminations shall be made for rusting or other damage to a container that might affect its water or air tightness.

(2) Containers of carbide which have been in storage the longest shall be used first.

(d) No carbide storage room shall be used for the storage of any other material except fuel gas cylinders, singly or manifolded.

(e) Trucks or wheelbarrows used inside carbide storage rooms shall be equipped with rubber or other nonsparking tires.

(f) There shall be no opening from the carbide storage room into any other room or building, except that if there be a partition between the carbide room and a generator room, a doorway will be permitted if all electrical equipment in the carbide room be installed in accordance with Electrical Safety Orders for hazardous locations.

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


1. Amendment of subsections (a), (b) and (c) filed 5-16-75; effective thirtieth day thereafter (Register 75, No. 20).

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

3. Amendment of subsection (b)2) filed 9-18-80; effective thirtieth day thereafter (Register 80, No. 38).

4. Amendment of subsections (c) and (f) filed 6-12-87; operative 7-12-87 (Register No. 26).

Go BackGo Back to Article 84 Table of Contents