
The primary importance of displaying safety signs and labels is to prevent injury and ensure staff and visitors are aware of the possible dangers and hazards ahead in certain situations and/or environments. Without these effective signs, many employees would lack the necessary direction in times of crisis, and employers might find themselves in significant legal difficulties if any accidents were to arise as a result. In order to minimize these potential accidents, ANSI Z535.4-2011 (R2017): Product Safety Signs And Labels sets forth a system for presenting safety and accident prevention information through product safety signs and labels.
The ANSI Z535.4-2011 (R2017) Standard for Product Safety Signs
ANSI Z535.4-2011 (R2017) delivers specifications for design, application, use, and placement of safety signs and labels on a wide variety of products. It defines a product safety sign or label as a sign, label, cord tag, or decal affixed to a product that provides safety information about that product. The American National Standard consolidates graphic approaches into a national and national common design to present product hazard and safety information in a visually consistent, uniform system. It also aims to minimize the proliferation of designs for product safety signs and labels. ANSI Z535.4-2011 (R2017) provides guidance for manufacturers, employers, distributors, and others who have a desire to communicate safety information via product safety signs or labels.
Product Safety Signs or Labels
A product safety sign or label, as specified in ANSI Z535.4-2011 (R2017), consists of a signal word panel plus a message panel. A signal word panel is an area of the safety sign that contains the signal word or words, and, when used, the safety alert symbol. The signal word communicates the degree or level of hazard seriousness. A message panel is an area of the safety sign that contains the word message. Other components— the specific hazard, the probable consequence of involvement with the hazard, and how the hazard can be avoided—are communicated through the word message and the optional use of a pictorial. Moreover, product safety signs or labels should alert persons to a specific hazard, the degree or level of hazard seriousness, the probable consequence of involvement with the hazard, and how the hazard can be avoided. Here are some specifications for product safety signs or labels in ANSI Z535.4-2011 (R2017):
- Border: should be safety white and if necessary to achieve better contrast, the border may be safety black
- Label or Sign Panel Format: may be in a horizontal or vertical format
- Message Panel: should have either safety black lettering on a safety white background or safety white lettering on a safety black background
- Message Panel Lettering: should be a combination of upper and lower case letters, where upper case only lettering may be used for short messages or emphasis of individual words
- Panel Shape: may be non-rectangular to make good use of the available space
- Safety Symbol Panel: should have a safety black symbol on a safety white background, and other colors may be used for safety symbol emphasis, such as safety red for fire, etc., or if surround shapes are used (see ANSI Z535.3 for recommended surround shapes and colors
- Standard Colors: Safety colors shall conform to ANSI Z535.1 (check out ANSI Z535.1-2022: Standard for Safety Colors)
- Signal Words: Signal words appear in sans serif letters in upper case only. The signal word NOTICE appears in italicized sans serif letters in upper case only.
What Is a Warning Sign in ANSI Z535?
A safety alert symbol indicates a hazard and is composed of an equilateral triangle surrounding an exclamation mark. DANGER, WARNING, CAUTION, NOTICE, and SAFETY INSTRUCTIONS or Similar Word are all signal words used in hazard alerting signs. Hence, a warning sign is a type of sign which indicates a potential hazard, obstacle, or condition requiring special attention, and it is displayed—as detailed in ANSI Z535.4-2011 (R2017)—as a safety black triangle, safety orange exclamation mark and indicates a hazardous situation which, if not avoided, could result in death or serious injury. These other signal word panels in the ANSI Z535 series require different label colors and signify different messages:
- DANGER is in safety white letters on a safety red background, indicating a hazardous situation which, if not avoided, will result in death or serious injury.
- CAUTION is in safety black letters on a safety yellow background, indicating a hazardous situation which, if not avoided, could result in minor or moderate injury.
- The word NOTICE should be in italicized safety white letters on a safety blue background and is used to address practices not related to physical injury
- The signal words used for a SAFETY INSTRUCTIONS sign or panel should be in safety white letters on a safety green background and indicate specific safety-related instructions or procedures

How Were Warning Signs Invented?
In the early twentieth century, a soaring rate of traffic deaths and injuries prompted concern; as a result, complex safety signage systems emerged. In 1908, the Automobile Association in West London erected some warning signs. In 1909, nine European governments agreed on the use of four pictorial symbols, indicating bump, curve, intersection, and railroad crossing. The intensive work on international road signs that occurred between 1926 and 1949 sparked to the creation of the European road sign system. Both Britain and the United States developed their own road signage systems that were adopted or modified by many other nations. The UK adopted a version of the European road signs in 1964 and, over past decades, North American signage started to use some symbols and graphics mixed in with English.
ANSI Z535 Series for Safety Color Code
ANSI Z535.4-2011 (R2017) is Part 4 in the ANSI Z535 Series on Safety Colors, which contains guidance for formats, colors, and symbols for safety signs used in environmental and facility applications, in product and product literature applications, and in temporary safety tag and barricade tape applications. It sets forth a hazard communication system that is designed to complement the ANSI Z535.2-2011(R2017), ANSI Z535.5-2011(R2017), and ANSI Z535.6-2011(R2017) standards. While these standards are similar in many respects, they each address different physical and visual requirements. As a result, the Accredited Standards Committee Z535 has recognized and affirmed the need for these separate standards. Here are the six standards that comprise the ANSI Z535 series:
- ANSI Z535.1 Safety Color Code
- ANSI Z535.2 Environmental and Facility Safety Signs
- ANSI Z535.3 Criteria for Safety Symbol
- ANSI Z535.4 Product Safety Signs and Labels
- ANSI Z535.5 Safety Tags and Barricade Tapes (for Temporary Hazards)
- ANSI Z535.6 Product Safety Information in Product Manuals, Instructions, and Other Collateral Materials
ANSI Z535.4-2011 (R2017): Product Safety Signs And Labels is available on the ANSI Webstore and in the ANSI/NEMA Z535 Set.