California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 7 - General Industry Safety Orders
Group 20 - Flammable Liquids, Gases and Vapors
Article 135 - General
Section 5418 - Carboys and Drums Containing Flammable Liquids

(a) Carboys or drums containing flammable liquids shall not be stored near steam coils or other source of heat.

(b) Carboys or drums containing flammable liquids shall not be emptied by air pressure except as produced by hand pumps or bulbs.

(c) No naked flame, torch, or similar source of ignition shall be allowed in contact with carboys or drums which contain or have last contained flammable or combustible liquids except for purposes of repair as provided in (d).

(d) Before repair work involving the use of open flames or other source of ignition, carboys or drums shall be purged of flammable vapors and insofar as is practicable, cleansed of residues which may give rise to such vapors. Ventilation, water, inert gas, or other suitable and effective means shall be used to prevent formation of explosive mixtures as necessary. Where such work is regularly or frequently undertaken, means shall be provided for testing the air in carboys or drums for explosibility.

(e) When carboys or drums containing or having last contained a flammable liquid are opened, any pressure which may have developed in the drum shall be relieved through a loosened plug before plugs are removed. During such operation, no source of ignition shall be permitted within 25 feet of the carboys or drums.