California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 2 - Boiler and Fired Pressure Vessel Safety Orders
Article 5 - Inspection
Section 775 - Operation of Unsafe Boilers

(a) If the operation of any boiler, including those exempt from annual inspection, constitutes a serious menace to the life or safety of any person employed about it, the division or any of its safety engineers, or any person affected thereby, may apply to the superior court of the county in which the boiler is situated for an injunction restraining its operation until the condition has been corrected.

(b) Whenever the condition of a boiler is such as to make it unfit for any pressure, a qualified safety engineer, employed by the division, may affix a rejection mark (o x) consisting of an "X" at least one inch (1") high with a circle at least one-half inch (1/2") diameter located between the upper arms of the "X." The rejection mark shall be outlined in center punch marks and located immediately above the state serial number.