Signal Words and Colors

What are the ANSI Z535 Signal Words and Signal Word Panel Colors?

The current signal words appearing in both the 2011 versions of the ANSI Z535.2 Standard for Environmental and Facility Safety Signs and the ANSI Z535.4 Standard for Product Safety Signs and Labels are as follows:

• DANGER
• WARNING
• CAUTION
• NOTICE

The signal word SAFETY INSTRUCTIONS appears in the 2007 ANSI Z535.2 standard and Clarion's submitted change proposal to include this signal word in the 2011 ANSI Z535.4 standard has been accepted by the ANSI Z535 committee. Note that equivalent phrases, such as SAFE OPERATION PROCEDURES or SAFE SHUT DOWN PROCEDURE, can be used in place of the words "SAFETY INSTRUCTIONS." This type of signal word panel is used for lists of steps, procedures or instructions that might otherwise clutter up a DANGER, WARNING or CAUTION safety label.

How do I choose the right signal word?

It is important for your safety signs and labels to have the appropriate choice of signal word because this word and its colored background designate a degree or level of hazard seriousness. The ANSI Z535 standards use the following definitions for signal words:

DANGER: Indicates a hazardous situation which, if not avoided, will result in death or serious injury. This signal word is to be limited to the most extreme situations.

WARNING: Indicates a hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION: Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury. Until 2011, the CAUTION signal word may also be used without the safety alert symbol as an alternative to "NOTICE." (Note: The option to use CAUTION for non-personal injury related safety signs and labels will be removed from the ANSI Z535 standards in their 2011 revision).

NOTICE: "NOTICE" is the preferred signal word to address practices not related to personal injury. The safety alert symbol shall not be used with this signal word.

The above definitions from the standard make it clear that CAUTION is to be used for minor injury. Minor burns, cuts, scratches, pinch points that result in bruises and minor chemical irritation are examples where CAUTION is an appropriate choice for the signal word. Deciding whether an injury is minor or moderate is a judgment call. Often this decision is based on whether a person can easily recover from the injury - that the injury is fully repairable (a bruise, minor burn, broken finger, etc.) and would not result in permanent disability, disfigurement, or pain.

Using CAUTION on safety labels meant for hazards that could (or will) result in serious injury or death is incorrect - this signal word does not adequately warn of the higher level of seriousness of the hazard as defined by the ANSI Z535 standards. Choosing to use CAUTION in place of WARNING or DANGER is a mistake that could have serious liability repercussions! Therefore, we recommend that you evaluate any CAUTION signs or labels you currently use in light of the ANSI Z535 definitions noted above and either reaffirm that they warn about minor or moderate injury, or change them to WARNING or DANGER if the sign or label's message is to warn about possible serious injury or death. Lastly, if your CAUTION messages are warning about non-personal injury related situations (such as property or equipment damage), now is the time to change them over to NOTICE so that your safety signs and labels will be in conformance to the 2011 revision of the ANSI Z535 standards.

Safety signs that use WARNING and DANGER signal words represent a huge portion of the tens of thousands of designs Clarion has created for its customers. Why? Because when it comes to equipment safety labeling, many of the safety messages that would use CAUTION for a signal word end up in the product's manual rather than appearing as labels on the equipment. The following questions should be asked to make a clearer judgment on which signal word would be most appropriate:

• Which potential hazards warrant the need for safety labels?
• Of the potential hazards that warrant safety labels on the product, which ones will or could result in causing serious injury or death?

Based on your answer to the second question, the signal word of DANGER or WARNING may be justified and you may well ask, "What type of injury is classified as serious?" This is another judgment call on your part. What we see is that serious injuries are ones that typically result in permanent loss of function, significant disfigurement, substantial and prolonged medical treatment, long periods of disability, and/or considerable pain and suffering (e.g. mangled or amputated fingers, third degree burns, loss of eyesight). Thus based on this classification, serious injuries fully deserve the use of WARNING or DANGER for the signal word on safety signs and labels meant to keep people from interaction with severe hazards.

How to choose between DANGER and WARNING?

If the resulting injury could be serious injury or death, the next question to ask has to do with sorting out which accidents have a high degree of probability of occurring and/or the injury occurring if the safety sign's message is ignored. Here is the thought process to consider when determining which signal word should be used in your safety message:

• If the safety message is ignored, "will" the person be seriously injured or killed? If yes, then DANGER should be the choice for your safety message.
• If the safety message is ignored, "could" the person be seriously injured or killed? If your answer is "yes" to this statement, then the use of WARNING is justified as your safety label's signal word.

For instance, if a person operates equipment without the guards in place, it does not mean that such an action "will" result in serious injury or death. Typically our customers choose to view this as a "could" situation and choose to use WARNING for the signal word. CAUTION is typically not used in this situation because the possible injury is almost always serious. On the other hand, let's say the hazard is an open blade on a band saw used in woodworking or meat processing, and the safety label's message warns about the cutting hazard and indicates that people should keep their fingers clear. If you were to ignore this safety label, the likelihood is very high that you will seriously cut or amputate your fingers. In this case, DANGER is clearly the right choice for the label's signal word. The consequence of interaction with the hazard is serious injury and it "will" happen if you ignore the safety label's message.

If you find that the majority of your safety signs and labels use DANGER, you probably should ask if the use of DANGER is being applied appropriately. According to the ANSI Z535 standards, the signal word DANGER should be used only for those hazards truly calling for the immediacy of injury that warrants communicating both a high degree of hazard severity (serious injury or death) and a high degree of probability of the accident/injury occurring.

To assist in the process of signal word selection, the ANSI Z535.2-2011 and ANSI Z535.4-2011 revisions include a new annex, Annex E, titled, "Risk Estimation and Signal Word Selection." Included within this annex are two signal word selection matrices that do a great job of defining the proper selection of signal word. Clarion's customer service staff will be happy to assist you with reviewing your signal word decision-making process in accordance with this annex.

What signal word can be used on safety labels meant for equipment damage or practices not related to personal injury?

If your safety labels are intended to warn persons about hazards that could result in only equipment damage or practices not related to personal injury, the signal word NOTICE (white letters on a safety blue background) should be used. NOTICE is the preferred ANSI Z535 signal word for this purpose. Note that the safety alert symbol is not used with this signal word because this symbol is only to be used where personal injury is at stake.

Note: DANGER or WARNING should not be considered for property damage accidents unless personal injury risk appropriate to these levels is also involved.

What is the safety alert symbol?

The safety alert symbol consists of a triangle with an exclamation mark and it appears to the left of the signal words DANGER, WARNING and CAUTION. In the vocabulary of ANSI Z535 signage, this symbol indicates that a possible personal injury hazard exists. The ISO 3864-2 standard refers to this same symbol as the "general warning sign" to indicate that a potential human risk of injury exists. The ISO version of this symbol is always colored yellow with a black band and a black exclamation mark. For more information on how the ANSI and ISO standards have been harmonized on this design element, click here.

Is it important to have the right colors on my safety labels?

Yes! You must use the right color combinations for the signal word panel. Both the Z535.2 Standard for Environmental and Facility Safety Signs and the ANSI Z535.4 Standard for Product Safety Signs and Labels state that DANGER should be shown in white letters on a safety red background, WARNING in black letters on a safety orange background, and CAUTION in black letters on a safety yellow background. Blue is then used for the NOTICE signal word panel and green for the SAFETY INSTRUCTION type of signal word panels currently found in ANSI Z535.2. Note that the SAFETY INSTRUCTION type of signal word panel was proposed by Clarion as an addition to the ANSI Z535.4 standard and our proposal was accepted for inclusion in the latest revision of ANSI Z535.4 (2011).

The actual safety colors of red, orange and yellow are specifically defined colors within very tight color tolerance boundaries as defined in the ANSI Z535.1 Standard for Safety Colors. Having the right colors is important because each of these colors signifies a different degree of hazard seriousness. If you venture out of these tolerances for each color, your safety message could be visually confused with higher or lower degrees of hazard/risk severity. For example, if your orange, used for WARNING, is too red, it could be confused with the color red, used for DANGER, possibly causing misinterpretation of the risk as higher than is present. At Clarion, we take matching the proscribed safety colors seriously because we fully recognize, along with the ANSI Z535 committee, that color is one of the key components to effectively communicating your company's safety messages.

Unlike most printers, Clarion uses pigments that are specifically formulated to match these ANSI Z535.1-defined colors. We know what we're doing here since the president of our company, Geoffrey Peckham, chaired the ANSI Z535.1 Standard's subcommittee from 1994-2008, whereupon he was appointed as the new chairman for the ANSI Z535.2 safety sign standard's subcommittee.

Does the theory of the use of color for designating different levels of hazard severity actually work?

The theory behind the use of clearly defined specific standardized safety colors is that through their long term use, people will come to intuitively understand the different degrees of hazard seriousness associated with each color's use on safety signs and labels. This theory only works if the colors are visually different. And that's the reason behind the ANSI Z535 standards mandating that safety colors fall within very tight (and clearly separate) color boundaries as shown on the spectrum locus curve (a chart that visually represents the visible color spectrum).

If you think it is impossible to use color to convey meaning, consider the very specific dark yellow color that's used for school buses and NYC taxi cabs. When you see a vehicle in either of these two respective shapes and in this color, you know what you are looking at - there is no confusion that the school bus is a truck or the cab is a passenger car. In short, Clarion fully backs the theory that color can denote severity level and that's why we go to the extreme of having our inks and pigments custom made to match the proscribed ANSI Z535.1 safety colors.