Whether on a circular saw, a chemical container or an electrical appliance – we encounter safety information, e.g. in the form of warnings, on a daily basis. But what at first glance looks like a simple sticker follows a sophisticated, empirically based system of colours, symbols and formulations. In the US, it is the ANSI Z535 series of standards that dictates what security-related information should look like – and it also influences the design of security information internationally. Anyone who develops or exports products for the American market cannot ignore this standard.
ANSI Z535 is a series of American National Standards Institute (ANSI) standards that define requirements for the design of safety signs, signage and safety literature. It consists of several parts that cover different areas of application:
ANSI Z535.1 – Safety Colours
ANSI Z535.2 - Environmental and Plant Safety Labelling
ANSI Z535.3 – Safety Sign Criteria
ANSI Z535.4 – Safety Labels on Products
ANSI Z535.5 – Safety tags (e.g. for maintenance and lockout/tagout)
ANSI Z535.6 – Product Safety Information in Manuals, Instructions and Similar Printed Accompanying Documents
ANSI Z535.7 – Product Safety Information in Electronic Media
For technical writers and product developers, Z535.4 and Z535.6 are especially relevant, as they directly affect the design of safety labeling and documentation. Z535.7 may sound interesting from the title, but it is only an uninspired copy of the Z535.6 and will therefore not be discussed further here.
The most well-known element of ANSI Z535 is the system of signal words and the associated colour coding. Each signal word communicates a certain degree of danger and is linked to a defined colour:
DANGER (Red): Indicates an imminent danger that will result in serious injury or death if not avoided.
WARNING (Orange): Indicates a potentially hazardous situation that may result in serious injury or death.
CAUTION (Yellow): Describes a situation that may result in minor or moderate injury.
NOTICE (blue): No risk of injury but indication of possible property damage or important procedural information.
The consistent use of these signal words is not optional; it has long been state of the art, translated into numerous other norms and standards (e.g. DIN EN IEC/IEEE 82079-1 or ISO 3864) and forms the basis for users to correctly classify warnings.
A complete warning according to ANSI Z535 includes at least four elements:
Signal word panel: The highlighted field with the signal word (e.g. WARNING on an orange background), in the case of hazards with a potential consequence of injury including the mandatory warning triangle ("safety alert symbol")
Type and source of hazard: A short, precise statement about what hazard exists and what it is due to
Consequences: What happens if the warning is ignored
Instructions for action: What the user should do or refrain from doing in concrete terms
A standard warning could look like this:
© kothes GmbH
Anyone who works internationally is also familiar with ISO 3864, the international counterpart to ANSI Z535. Both standards pursue similar goals but differ in some essential respects:
Signal words: ANSI Z535 and ISO 3864 recommend identical signal words for hazards with possible consequences of injury. ANSI also recommends NOTICE for potential property damage. There is no equivalent in ISO 3864.\
ISO 3864 relies more on the use of pictograms, regardless of the signal word topic.
Colours: The colour codes are fundamentally different, e.g. when using orange for WARNING (ANSI) versus yellow for warnings (ISO). Therefore, we advise against a "one-fits-all"solution with ISO symbols for the USA (see also below).
Symbol design: ISO 3864 prescribes geometric frames for symbols (triangle = warning, circle with bars = prohibition), while ANSI Z535 is much more flexible here.
Many companies that sell their products in both markets ask themselves this question. The short answer: Neither ISO 3864 nor ANSI Z535 are legally required in the sense that a violation automatically entails a sanction. Both are technical standards, not laws. Nevertheless, in practice they have a non-negligible binding effect.
In Europe, standards such as DIN EN IEC/IEEE 82079-1 refer to ISO 3864 (in conjunction with EN ISO 7010) as a recognised state of the art. Anyone who deviates from this must prove in case of doubt that the chosen solution is equally safe.
In the USA, the same applies to ANSI Z535: It is not a law, but is used as a benchmark by courts and authorities. Anyone who has to prove that a product has given sufficient warning in the event of damage is on thin ice without ANSI compliance.
Can I also use ANSI Z535 in Europe? Yes, and this is quite common in practice. The harmonisation efforts of both organisations (ANSI and ISO) date back to the early 2000s. It is crucial that the safety information is understandable, complete and designed according to the state of the art – regardless of which standard serves as the basis. The ANSI relies a little more on textual support, which can be of advantage when it comes to clarity and comprehensibility.
TIP: If you sell products globally, it is best to go with a dualised documentation strategy that takes both cultures into account. This saves effort during market launch and minimises liability risks on both sides of the Atlantic.
The theory is one thing, the implementation in practice the other. For the latter, these recommendations have proven successful:
Risk assessment first: Before safety information is created, it must be clear what the actual risk is and how serious it is. This results, among other things, in selecting the most appropriate signal word.
Clean derivation: Safety information must be properly derived and checked for plausibility, and even justified depending on the target group. Didactics should not be neglected, especially when it comes to safety information. The specific implementation depends largely on who reads the instructions. Specialist personnel with relevant training (such as service technicians) require less detailed explanations than end users without prior technical knowledge. Products in the B2C sector generally require more detailed and explicit safety and warning notices, since US product liability law places particularly high demands on comprehensibility for laypersons. ANSI Z535.6 expressly recommends that safety information be tailored to the respective target group (including Appendix B).
Use meaningful symbols: The advantages of using standardised symbols are undisputed and do not need to be advertised here. However, if there is no one symbol in the pool of standardised symbols that adequately conveys the message, it may be advisable to get creative and adapt yourself. According to ANSI Z535.3, manufacturers are instructed to first validate the comprehensibility of their symbols. Here, in turn, it can make sense to dispense with symbols in case of doubt and to produce clarity verbally.
Ensure legibility: The font size, contrast and material of the safety information must also function under real operating conditions (light, dirt, temperature).
Consistency of all touchpoints: The same hazards must always be labelled in the same way – on the product, in the manual and on the packaging.
Many medium-sized companies are faced with exactly this task: An operating manual, which has already been drawn up according to European standards such as DIN EN IEC/IEEE 82079-1 or the Machinery Directive 2006/42/EC (will be replaced by the EU Machinery Regulation (EU) 2023/1230) from January 2027, should be adapted for the US market. This is not a complete restart, but targeted adjustments are necessary:
1. Review existing risk assessment for US requirements
The basis of any safety information is the risk assessment. In the USA, there are different expectations for product safety and liability than in Europe. It is advisable to review the existing risk assessment with a view to the US market, since the assumptions about, for example target groups and their qualification levels but also about application situations and environmental conditions, may or even have to be different.
2. Customise signal words
European guides often use translations of the original ANSI signal words DANGER, WARNING, CAUTION and NOTICE. If the signal words are translated back in the course of localisation for the North American target market, ensure that DANGER, WARNING, CAUTION and NOTICE are actually used again (and, for example, brief the translation service provider accordingly).
3. Adjust the shape of the warnings
Many manufacturers have now realised that the rest of the world can live well with ANSI formatting, especially ANSI colour coding, and have switched directly to red, orange, yellow and blue. Anyone who has hitherto wanted to stick to a German/European appearance for their German/European instructions (e.g. only yellow-black warning triangles or no warning triangles at all) is well advised to Americanise this at least for the target market USA according to ANSI.
4. Replace symbols if necessary
European instructions often use symbols according to ISO 7010 or ISO 3864. All colours are assigned differently according to ANSI. The significance of some pictograms established in Europe must be questioned in general and for the USA in particular. Important: Symbols must be checked for comprehensibility in accordance with ANSI Z535.3.
5. Structure the warnings according to the ANSI pattern
ANSI Z535.6 recommends a clear structure of hazard description, consequence and instructions for action. Existing warnings should be checked to this effect and, if necessary, missing elements should be added.
6. Language: Ensure US English and readability
For the US market, the instructions must of course be in US English. The following applies: Simple, clear language – no technical terms without explanation, no nested sentences. ANSI Z535 implicitly emphasises unambiguous wording that is also understood by people without specialist knowledge. US jurisdiction tends to attach great importance to proactivity and precision.
7. Adapt safety marking on the product (ANSI Z535.4)
In addition to the instructions, the safety signage on the product itself must also be checked. This is subject to ANSI Z535.4 with its own design requirements that differ from those for instructions (Z535.6). Anyone who only adapts the instructions but forgets the safety signs is not fully ANS-compliant despite all efforts. And: As soon as the signage on the product has been adapted, the corresponding chapter of the manual must also be adapted.
INFO: The focus of this article is on the ANSI Z535 series of standards and compliance with them. For an adequate localisation of a non-US manual, as you know, further adjustments are required independently of ANSI. We refer, for example, to the Americanisation of units, professional group designations, elimination of references to German/European standards and the like.
The ANSI Z535 is regularly revised. Companies should check whether their security information is still up to date – especially if:
Products are revised or re-certified,
New hazards arise due to changed use,
Markets are opening up that explicitly require conformity to standards.
The ANSI Z535 is much more than a formal requirement. It is a well thought-out system designed to protect against injury or worse – provided it is applied consistently and correctly. The following applies to those responsible for documentation: Anyone who designs safety information in accordance with standards not only protects users, but also their own company from liability risks.
Do you have questions about the implementation of ANSI Z535 in your documentation or on your products? Talk to us – we help you to make security communication professional and compliant with standards.