The Origin of the Z535.1 Standard

ANSI Z535 is an American series of standards that provides a system for presenting safety and accident information – making it an important guideline for developing best practice safety labels and signs. One of the standards in this series – ANSI Z535.1 – focuses specifically on safety colors. ANSI Z535.1 is the oldest of the family of ANSI Z535 standards. It originated as the American War Standard in 1945, which contained a “Safety Color Code.” It was developed at the request of the War Department and approved by the American Standards Association (ANSI’s original name) – and has evolved since then. The most recent version and full name of this standard is: ANSI Z535.1-2022: Safety Colors. It provides guidelines for the use of colors in safety signs, labels, tags, and markings to communicate hazards and safety information effectively.

Why Color Accuracy in Safety Symbols, Labels, and Signs Matter

Many warnings and instructions (safety labels and safety signs) use color to supplement a word message or safety symbol. The use of so-called ‘safety colors’ may help to increase a worker’s recognition of the hazard and increase necessary reaction time to hazardous situations or emergencies. When color is used in a standardized way, or in a color-coding system, it can help to create a unified look for safety symbols or labels used to warn about hazards on equipment or in a workplace.

“Effectively communicating hazards is vital for safety. The use of color can help with comprehension and understanding of safety messages, but it has to be very specifically defined,” says Angela Lambert, our head of standards compliance here at Clarion Safety Systems, and the chair of the ANSI Z535.1 subcommittee.

What is ANSI Z535.1?

ANSI Z535.1 establishes safety color codes intended to alert and inform people to take precautions in the presence of hazards. This color coding is used across safety labels, signs, and tags and for the identification and location of fire equipment, first aid equipment, obstacles, and other hazards.

Using ANSI Z535.1 color codes helps to create a unified look for hazards in workplaces and on equipment, which can help increase a worker’s recognition and increase the reaction time in an urgent situation. The standard defines, in scientific terms using charts and diagrams, the technical definitions, color standards, and color tolerances for these colors: safety red, safety orange, safety yellow, safety green, safety blue, safety purple, safety black, and safety white.

The Goal of ANSI Color Standardization

According to the standard, its intention is to provide, “a system for specifying safety colors, in terms of Munsell notations, CIE colorimetric data, defined chromaticity regions, and color formulas for each ANSI and ISO safety color used on safety signs, labels, and tags.”

As outlined in the standard itself, its purpose is to:

• Implement a uniform system for specifying safety colors
• Include safety color formulas for a variety of applications and media for specifying ANSI and ISO Safety Colors (in Annex C)
• Harmonize with safety colors specified in the Code of Federal Regulations
• Harmonize with ISO 3864-4, Graphical symbols—Safety colours and safety signs

Recent Updates to ANSI Z535.1

ANSI Z535 is reviewed and updated on a periodic basis, and 2022 and 2023 are revision cycle years. In its most recent update, ANSI Z535.1 was republished in 2022, revising the previous version which was published in 2017. The 2022 edition – the tenth revision of the standard since its origin – incorporated minor updates to how it relates to and can be combined with other applicable standards and regulations.

Using Safety Color Best Practices in your Symbols, Labels, and Signs

When it comes to using best practice for colors in your safety symbols, labels, and signs, it’s important to understand and use the specifications outlined in ANSI Z535.1. “ANSI Z535.1 safety colors are tightly defined and should be adhered to for proper color discrimination or color coding,” Angela says.

For how to use or apply color, keep in mind that ANSI Z535.1 only defines the colors themselves, not their uses. One of the major revisions of the ANSI Z535.1 Safety Color Code in 2002 was to delete information concerning the application of the safety colors. Per the standard, “The intention of making this change was to maintain Z535.1 as the standard that defines the safety colors in terms of their color tolerances. The application of the colors (i.e., how they are to be used) properly belongs to the other standards in the ANSI Z535 series as well as to other standards that include uses for safety colors.”