Defects in Warnings and Instructions

Kenneth Ross


As the common law of products liability has evolved over the years, three defects that exist in the product at the time of sale have been identified as the main components of a products liability lawsuit. These are manufacturing defects, design defects, and defects in warnings and instructions. The test for determining when there is a manufacturing defect is objective. However, the test for defects in design and warnings and instructions is very subjective and based on reasonableness factors to be decided by the jury.

Therefore, determining when there is a duty to warn or instruct and how far that duty extends is one of the more difficult questions that needs to be answered by any manufacturer. And, unfortunately, for devices marketed under a 510(k) substantial equivalence approval, compliance with FDA laws, regulations, or guidances is not a defense in a products liability case. Therefore, when analyzing a device manufacturer’s responsibilities in this area, you need to consider both your common law duties as well as FDA duties.

The jury can easily conclude that an injured plaintiff would not want to be hurt or killed and if the manufacturer had provided adequate warnings and instructions, the plaintiff would have followed them and not been hurt or killed. With medical devices, it is also easy to argue that a healthcare practitioner would not want to injure themselves or the patient. Therefore, the fact that an accident occurred can mean, by definition, that it is possible that the warnings and instructions were inadequate.

This makes it easy for the plaintiff to argue that there was a defect in warnings and instructions and that the defect caused the injury, and often more difficult for the manufacturer to explain why its warnings and instructions were sufficient.

This duty should be distinguished from the post-sale duty to provide warnings. Post-sale warnings are provided after a product has been sold and is in use, and usually result from an adverse incident or near-miss indicating that the original design or warnings and instructions are somehow deficient. This duty will be discussed in a subsequent article.

Basic Common Law Duty

A manufacturer has a duty to warn where: (1) the product is dangerous; (2) the danger is or should be known by the manufacturer; (3) the danger is present when the product is used in the usual and expected manner; and (4) the danger is not obvious or well-known to the user.

Another way to state this is that there is a defect in the warnings when reasonably foreseeable risks of harm posed by the product could have been reduced or avoided by providing reasonable instructions or warnings, and the omission renders the product not reasonably safe.

There is an interrelationship between adequate design and adequate warnings. For this article, we will assume that the manufacturer designed the product as safe as necessary and that hazards remain. No matter how safe the design, most products have residual risks and need warnings, either affixed to the product or in the instructions.

Difference between Warnings and Instructions

Instructions affirmatively inform persons about how to use and consume products safely. Warnings alert users and consumers to the existence and nature of product risks. Generally, warnings tend to be negative statements about things not to do or affirmative statements about things always to do. Instructions tend to describe in more detail how to do something safely and correctly.

The safety information on warning labels attached to the product can be a mix of affirmative, negative or instructional information. The same is true for safety information in instructions that accompany the product. With this combination of information, users and health care providers can minimize the risk of harm by following the warnings and instructions during use or by choosing not to use the product.

Warnings are usually contained in labels attached to the product or to the packaging or in hang tags that are attached to the product but are thrown away after purchase. Warnings can also be included in instructions that accompany the product and in a company’s website and promotional literature. With many medical devices, warnings and instructions may also transmitted by training programs provided on-site to health care providers.

Determining Risk and Whether to Warn

During the design phase, manufacturers should do some sort of a risk assessment. This assessment identifies possible hazards with using the product and quantifies the probability that this hazard will occur and the severity of the harm that will be suffered if it occurs.

When this is completed and the product’s design has been established, it should be relatively easy to identify residual risks about which there should be a warning. If the risk is not sufficient or not reasonably foreseeable, then maybe no warning is necessary. There are no rules under the common law to tell a manufacturer when the risk is too small to warn about or when a risk is reasonably foreseeable. The jury gets to second guess the manufacturer’s decision about whether to warn and about the content of the warning.

If the risk is obvious, a warning may not be needed. But this decision must be made carefully because the risk, and the probability and severity of harm, may not be obvious to some potential product users. Unfortunately, there are very few clear guidelines in this area. This is one reason why manufacturers may warn about those hazards that even seem remote or obvious.

Once a warning is created, however, the guidelines, standards, and law are a little clearer. But making this initial decision can be tough and one that should not be done without legal counsel experienced in the area of warnings.

Adequacy of Warnings – Common Law, Regulations and Standards

Once the decision has been made to warn, the manufacturer needs to determine who to warn and whether the warning is adequate. The common law has said that a warning is legally adequate if:

  • it is in a form that could reasonably be expected to catch the attention of a reasonably prudent person in the circumstances of the product’s use;

  • the content is of such a nature as to be comprehensible to the average user; and

  • it conveys a fair indication of the nature and extent of the danger to the mind of a reasonably prudent person.

  • Despite this definition, terms such as “reasonable user,” “fair indication,” and “reasonably be expected to catch the attention of the user” make it clear that the jury gets to decide the adequacy of the warnings. Also, previous cases are not particularly helpful because there are so many variables with each particular hazard, the avoidance procedures, and the experience of the readers of the warnings. Is the reader educated, uneducated, skilled, unskilled, and illiterate or do they have poor reading skills, etc?

    On the positive side, there are FDA requirements (discussed below) and U.S. standards (one of them is referred to as ANSI Z535.4) for designing warning labels that, if followed, will result in labels with a high degree of uniformity. The ANSI standard requires that labels use a signal word – DANGER, WARNING, or CAUTION – as well as possibly a pictorial or symbol, and then text. And, the text is supposed to describe the hazard, the probability of harm, the severity of the harm, and how to avoid the harm.

    Beyond that, the ANSI standards do not tell a manufacturer how to determine if a warning is required and what language or picture to put on the label. For that, the manufacturer needs to make some important decisions. Again, because of the significant legal consequences from making a bad decision, consulting a lawyer experienced with developing warnings is imperative.

    A lawyer may not be necessary if you are copying competitors’ labels that appear to have been developed by competent people. But, it is still a good idea for a label specialists to review the labels to be sure they apply to your product and are likely to comply with applicable laws and standards.

    Who do you have to warn?

    The general rule is that the manufacturer must warn all foreseeable users (i.e. health care practitioners and patients) about hazards in the product. However, there is an exception for medical products that can only be obtained or used through a medical professional which provides that warnings must only be provided to the physician and not directly to the user. This exception is called the “learned intermediary doctrine.”

    The physician, in turn, then has a responsibility to inform the patient of the hazards involved with using the medical device and how to use it properly and safely. However, the manufacturer must still provide adequate information to the physician about hazards and safe use. The difference is that they can then assume that the physician will interpret it and pass along the information to the patient.

    There are some courts that have concluded that this rule does not make sense in some situations, such as when the manufacturer engages in direct-to-consumer advertising. The FDA has provided guidance on warnings provided to ultimate patient users about medical devices that are used at home (see Write It Right referenced below).

    Healthcare professionals want warnings and instructions that are written clearly and succinctly. They need to be able to find the information and interpret it for their use or for providing to the patient. If they can’t easily find the information or difficulty understanding what is being said, this could create problems for the manufacturer in the event of adverse incidents.

    Therefore, despite the “learned intermediary doctrine,” manufacturers should strive to provide warnings and instructions that are likely to be read and understood by the ultimate user as well as the learned intermediary and to provide them so that the patient will be able to see them if necessary.

    Other considerations

    Difficult issues remain that must be decided by the manufacturer. Does a label have to be attached to the product or can the information go in the manual? How big should the label be? Where should it be placed? What kind of material should it be made of? How should it be attached? Should any language other than English be on the label? Should the warning on the label be repeated in the instructions?

    The manufacturer has to anticipate how it will argue that the information was clear and accessible, and that the user understood the importance of reading and following the warnings and instructions in the event the product becomes the target of a failure to warn claim.

    There are no clear guidelines about what warnings go on the product and which ones go in the instructions. The manufacturer must decide, based in part on how necessary it is for the user to see the warning each time the product is used, or only once, or only periodically when the manual is read or referenced.

    In addition, location of the safety information in the manual is important to enhance the argument that the health care practitioner or user must have seen the warnings given the placement and prominence of the information. Usually, manuals of some length include a safety section at the front where safety information and reproductions of the safety labels are included. This safety information may be repeated in the text of the manual in the location where the hazard exists. In short manuals, this section may not need to be included, and the safety information is just in the instructional text.

    The manufacturer must consider how to get the manual to the user and make it accessible during use or maintenance of the product. This cannot always be done and, many times, the warnings on the product will have to stand alone in providing critical safety information during use.

    FDA requirements

    The FDA has a number of documents detailing various labeling requirements previously found on the FDA site: Labeling - Regulatory Requirements for Medical Devices (FDA 89-4203); Write it Right; Device Labeling Guidance #G91-1 (blue book memo); Guidance on Medical Device Patient Labeling; Final Guidance for Industry and FDA Reviewers; Guidance on Labeling for Laboratory Tests; and Human Factors Principles for Medical Device Labeling.

    These documents provide very general and some specific requirements depending on the device. They incorporate the law, regulations, and guidances, including references to voluntary standards.

    Also, since it is clear that all advertising and promotion is considered part of labeling, there are additional FDA documents concerning risk communications in general. See Guidance for Industry Presenting Risk Information in Prescription Drug and Medical Device Promotion and Strategic Plan for Risk Communication at the Food and Drug Administration.

    During the 510(k) process, the FDA will review the product’s intended warnings and instructions. But as long as they meet the basic requirements, the FDA probably won’t comment further. Under products liability law, the manufacturer may still be subject to an argument that they should have exceeded the basic requirements and provided adequate warnings and instructions for the “reasonably foreseeable” user.

    Under the more rigorous analysis during the PMA process, the manufacturer can rely on the FDA’s approval and they should have an absolute defense to a failure to warn claim in a products liability case.

    Other safety communications

    Many times, people do not read warnings and instructions until they are having problems with the device or until they hurt themselves. We cannot make people read safety communications. But one reason they do not read them is that they are not very interesting and are many times difficult to understand.

    So, when considering safety information, we should think about other ways to communicate it in a more interesting and obvious way, for example, with the use of pictures or diagrams. For years, medical device manufacturers have provided on-site training programs for health care professionals. The difficulty for manufacturers has been getting some professionals, especially the doctors, to attend.

    As a result, instruction or safety videos, posters and web-based interactive safety training may be important to supplement the written material and the onsite training. The technology is available to create such materials and the cost not that significant. Manufacturers should consider going beyond written safety communications to adequately communicate the message.


    This area of products liability law is dangerous because it is so easy for a plaintiff to argue that the manufacturer should have added a few more words and the accident would not have happened. As a result, creating new warnings and instructions (or updating your current warnings and instructions) should not be done without first obtaining assistance from legal counsel, engineers, and label suppliers that know how to design and produce labels and manuals that comply with any applicable laws and standards. Once the labels and manuals have been developed correctly, it is comparatively easier to update or modify them in the future.

    Complying with the duty to warn and instruct in the United States and in foreign countries is not easy. The manufacturer must seriously undertake an effort to do so, both for the safety of the users and to enhance the ability to sell the product both here and abroad. This article and the previous article on design defects touched on the most important aspects of this duty. But it only scratched the surface and was intended for people to understand how difficult this area of products liability law can be.

    Kenneth Ross

    Kenneth Ross is Of Counsel to the Minneapolis office of Bowman and Brooke LLP where he practices in the areas of product safety and liability prevention and advises manufacturers, product sellers and insurers on ways to identify, evaluate and minimize the risk of products liability and contractual liability. These guides do not constitute legal advice and are very general. You should consult competent legal counsel or Medmarc Loss Control before acting on any of the information in these guides.

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