29 C.F.R. § 1915.16 Warning signs and labels.
Title 29 - Labor
(a) Employee comprehension of signs and labels. The Employer shall ensure that each sign or label posted to comply with the requirements of this subpart is presented in a manner that can be perceived and understood by all employees. (b) Posting of large work areas. A warning sign or label required by paragraph (a) of this section need not be posted at an individual tank, compartment or work space within a work area if the entire work area has been tested and certified: not safe for workers, not safe for hot work, and if the sign or label to this effect is posted conspicuously at each means of access to the work area.
Title 29: Labor
PART 1915—OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT
Subpart B—Confined and Enclosed Spaces and Other Dangerous Atmospheres in Shipyard Employment
§ 1915.16 Warning signs and labels.
