Answer:
Danger signs — Indicate immediate danger and that special precautions are necessary. OSHA specifies that red, black and white colors are to be used for danger signs.
Caution signs — Warn against potential hazards or caution against unsafe practices. OSHA specifies that caution signs must have a yellow background and black panel with yellow letters. All letters used against the yellow background must be black.
Safety instruction signs — Must be used where there is a need for general instructions and suggestions relative to safety measures. OSHA specifies that safety instruction signs must have a white background, green panel and white letters. Any letters used on the white background must be black.
ANSI Z35.1-1968 (Specifications for Accident Prevention Signs) is incorporated by reference into 29 CFR 1910.6(e)(59). ANSI Z53.1-1967 (Safety Color Code for Marking Physical Hazards) is incorporated by reference into 29 CFR 1910.145(d)(2), (4), and (6). Although still referenced both of these standards have become inactive and been replaced by the ANSI and NEMA Z535 series of safety alerting standards. In the fall of 2013, OSHA endorsed the latest best practices related to safety signs by referencing the 2011 ANSI/NEMA Z535 safety sign and tag standards in its regulations (Federal Register Volume 78 Number 215 November 6, 2013). ANSI Z535 was reaffirmed in 2017, with only minor changes to the technical specifications for colors.
The ANSI/NEMA Z535 series is composed of six documents and a color chart:
ANSI/NEMA Z535 Color Chart
ANSI/NEMA Z535.1 Safety Colors
ANSI/NEMA Z535.2 Environmental Facility and Safety Signs
ANSI/NEMA Z535.3 Criteria for Safety Symbols
ANSI/NEMA Z535.4 Product Safety Signs and Labels
ANSI/NEMA Z535.5 Safety Tags and Barricade Tapes (for Temporary Hazards)
ANSI/NEMA Z535.6 Product Safety Information in Product Manuals, Instructions and Other Collateral Materials
Explanation: