Vredenburgh & Zackowitz, Inc.

Human Factors, Ergonomics, Safety,
Engineering & Organizational Consulting


Warnings, Product Design, Risk Perception


Vredenburgh, A.G., Zackowitz, I.B. & Vredenburgh, A.N. (2019). Colorful Rounded-Tip Scissors: Too sharp for children. M.S. Wogalter (Ed.), In Forensic Human Factors & Ergonomics: Case Studies and Analyses, (pp. 123-134). Boca Raton, FL: CRC Press/Taylor & Francis Group.

Vredenburgh, A.G. & Zackowitz, I.B. (2018). Forensic Case Study: When labeling leads to wrongful incarceration. In Proceedings of the Human Factors and Ergonomics Society 2018 Annual Meeting, Santa Monica, CA: Human Factors and Ergonomics Society, 398-402.

This case study involves a woman who travelled to Mexico and returned to the United States transporting bottles of cuajo, a substance derived from a calf’s stomach, which is used to make cheese. She informed the border officer that the liquid in the bottle was used to make cheese and she had receipts in her possession for purchasing cuajo. A Safariland NarcoPouch field drug kit was used to test the liquid, which produces an expected color change to any substance that contains secondary amines, including methamphetamine and MDMA. A positive test result to the cuajo when tested at the Port of Entry was a major factor in deciding to arrest the woman, who was held in jail for more than six months; the results of gas chromatograph/mass spectrometer testing indicated that there was no controlled substance in the bottles and she was released. The human factors issues for this matter include adequacy of training, instructions and warnings which misled officers to believe that the test was conclusive for methamphetamine, resulting in her lengthy incarceration.

Bench, M.L., Vredenburgh, M.J., Zackowitz, I.B. & Vredenburgh, A.G. (2017). Risk Communication for Consumer Products. Pedro Arezes (ed.), In Advances in Safety Management and Human Factors, (pp. 225-235). Warsaw, Poland: Springer International Publishing.

There are many ways that product manufacturers can communicate risk to consumers. The hazard control hierarchy describes the fundamental elements and appropriate methodology for implementation of research-supported concepts and provides effective techniques for risk communication. Distinctions among types of risk communication and relevant standards are reviewed. Comprehension of risk information by product users is an essential part of the communication process. Label conspicuity and placement on the product are considered as to how they impact the efficacy of a warning, and are evaluated in real-world applications. Anti-warnings: communications that downplay risks and/or undermine warnings are also important to consider and are discussed relative to their effect on warning communications.

Huyen, C., Vredenburgh, A.N., Zackowitz, I.B. & Vredenburgh, A.G. (2017). Role of emotions in risk perception. Pedro Arezes (ed.), In Advances in Safety Management and Human Factors, (pp. 133-143). Warsaw, Poland: Springer International Publishing.

Emotions play an important role in risk perception. There are many ways in which users’ personal feelings can impact their evaluation of and reaction to product risks. Strong emotions and overall affect can influence behavior and decision-making in a manner distinct from related stimuli. In order to explore this relationship, the process of risk-benefit analysis is observed through an evaluation of several different activities and products, such as adrenaline sports, gambling, and smoking.

Zackowitz, I.B. Vredenburgh, M.J., Bench, M.L., & Vredenburgh, A.G. (2017). Types of Consumer Products. In G. Emilien, R. Weitkunat & Ludicke (Eds.). Consumer Perception of Product Risks and Benefits. (pp. 3-22). Switzerland: Springer.

This introductory contribution considers the extensive range of consumers, consumer products and the categories within which they can be considered. Consumer products are those, which are used by the consumer for personal consumption or for household use. No longer does the simple paradigm of storefronts and tangible products dominate today’s consumer marketplace. Instead, intangibles, like digital goods, are becoming more common consumer products. Whether the item is baby food, a cosmetic like lipstick, or even a cosmetic for a character in a video game, there is one underlying similarity: they are purchased. This contribution describes how consumer factors, such as age, education and socioeconomic status influence purchase decisions and examines both the obvious and not so obvious categories of products available to Global consumers. Marketing considerations discussed include consumer buying behavior, distribution and effective promotional efforts for the different categories of products.

Wogalter, M.S. Laughery, K.R., Vredenburgh, A.G., Deppa, S.W., Lueder, R. & Zackowitz, I.B. (2014). Child Injury: Forensic human factors points to the need for better product designs and warnings. Proceedings of the Human Factors and Ergonomics Society 58th Annual Meeting, Santa Monica, CA: Human Factors and Ergonomics Society, 58:1864-1868.

A set of cases concerning child injury is described in which there are several human factors/ergonomics (HFE) issues. Each panelist describes an injury or death of a child with a brief overview of the events that occurred. Major HFE issues are presented and discussed using the framework of the hazard-control hierarchy of designing out, guarding against, and warning about hazards. Consideration is not only given to children but also caretakers in the design of useable and safe products. A secondary purpose of the panel is to discuss interest in forming a special interest or technical group on children’s HFE issues.

Vredenburgh, A.G., & Spencer, D.R. (2013). Sophisticated User: When Does a Jury Find Users to Have Sophisticated Knowledge after Determining Liability/Failure to Warn? Proceedings of the Human Factors and Ergonomics Society 57th Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, Vol. 57, 565-569.

This study evaluates the legal term “sophisticated user.” With increasing frequency, Defendants are relying on this defense to mitigate a failure-to-warn finding. It is the jury’s duty to determine which users are sophisticated, based on jury instructions given by the judge. This study evaluates the sophisticated user defense in terms of a recent Federal case finding, in which a jury found a failure to warn, along with finding that the user was sophisticated. The jury instructions in this case include several elements, any one of which may lead a jury to determine that a Plaintiff is sophisticated without any corroborating evidence; this study examines each element separately.

Vredenburgh, A.G., & Zackowitz, I.B. (2012). Case Study: Evaluating the Warnings on a Tanning Bed. Proceedings of the Human Factors and Ergonomics Society 56th Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, Vol. 56, 671-674.

When human factors professionals are retained to evaluate a product and its labeling after an injury, other relevant information must be considered to determine if additional warnings may have led to a different outcome. This case study evaluates an incident where a woman alleged that a tanning bed had inadequate warnings. When evaluating the case, the product design, user interface, and relevant communication system standards were considered along with the plaintiff’s personal knowledge and behavior. The warnings were also evaluated in the context of the tanning establishment and its trained employees. This case illustrates the circumstances when manufacturer’s product design and labeling was not a causation factor of an incident.

Vredenburgh, M.J., Zackowitz, I.B., Spencer, D, DeTaboada, M.R, & Vredenburgh, A.G. (2010). What constitutes typical adolescent behavior and how does it differ from adult conduct? In Waldemar Karwowski & Gavriel Salvendy (Ed.). Advances In Human Factors, Ergonomics, and Safety Manufacturing and Service Industries. 927-936.

Adolescence is a period that includes children ranging in age from 12 to 18 years. At this time, children are beginning to develop their own identities and are greatly concerned about peer approval. Adolescents are at great risk for being involved in injury incidents due to developmental characteristics unique to this age group. As human factors and safety consultants, we analyze multiple incidents every year that involve adolescents. In order to gain perspective on adolescent behavior, we developed a survey that was administered to the adolescents themselves. This differs from much past research on the topic that relied on hospital data and parent perceptions. This paper discusses common adolescent risk-taking behavior and their limited self-protective behavior.

Vredenburgh, A.G. & Zackowitz, I.B. (2009). Drug Labeling and its Impact on Patient Safety. In Sonja Koneczny (Ed.), WORK: A Journal of Prevention, Assessment & Rehabilitation, Volume 33, Number 2. (pp. 169-174). The Netherlands: IOS Press.

Adverse drug events (ADE) are defined as any medication error with significant potential to harm a patient (Fortescue et al, 2003). Often times, ADEs occur due to inadequate or ineffective systems of labeling. These ADEs often result in mistakes in prescription adherence (compliance) with the prescription instructions. These mistakes are costly and can be deadly. Potential problems with drug labeling can occur in both in-patient and out-patient environments. This paper discusses some of the key issues to consider in drug labeling and its impact on patient safety.

Vredenburgh, A.G. & Zackowitz, I.B. (2008). Drug Labeling and its Impact on Patient Safety. In Proceedings of the Human Factors and Ergonomics Society 52nd Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 842-844.

Adverse drug events (ADE) are defined as any medication errors with significant potential to harm a patient. ADE frequently occur due to inadequate or ineffective systems of medication labeling. These ADE often result from mistakes in adherence (compliance) with the prescription instructions. Potential problems with drug labeling can occur in both in-patient and out-patient environments. This paper discusses some of the key issues to consider in drug labeling and its impact on patient safety.

Zackowitz, I.B. & Vredenburgh, A.G. (2008). When is a Warnings Case Not a Warnings Case? Proceedings of the Applied Human Factors and Ergonomics 2nd International Conference, Las Vegas, NV.

In this paper, we describe two forensic cases in which plaintiffs claim that an incident was due to a failure of a manufacturer to effectively warn them. Human factors consultants may be asked to evaluate whether the incidents were due to ineffective hazard communication. Sometimes, a case may appear to focus on warnings, but after further analysis it becomes evident that other factors are the critical issues. Both case studies involve property damage resulting from fires. The first discusses a dryer fire at a fast food restaurant. The second case study examines a fire resulting from the heating of frozen pipes with a blowtorch. These cases will illustrate that while in general warnings are important to increase public safety, they may not be relevant to the behavior involved in the incident. In these two case studies, while plaintiffs claim a failure to warn, we demonstrate that hazard communication was not a causal factor.

Kalsher, M.J., Cao, C.G.L., Weinger, M., Vredenburgh, A.G., Israelski, E., Spyridon, G., Yoshida, D., & McLeod, R. (2007). Mock Trial: Role of Human Factors in Litigation Involving Automated External Defibrillators (AED). In Proceedings of the Human Factors and Ergonomics Society 51st Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 1514-1516.

This special joint session (sponsored by Health Care TG and Forensics TG) at the 2007 annual meeting of HFES presents an enactment of a court trial involving an automated external defibrillator (AED). The mock trial session presents human factors issues related to the design and use of the AED which lead to the death of an individual who collapsed in an airport. Human factors experts for the plaintiff and the defense will each weigh in on the circumstances surrounding the death of the victim, with examination from the respective attorneys, and cross examination from the opposing attorneys. A panel of commentators provides reactions and opinions after each side has given its testimony. However, no judgment or verdict on the case will be reached at the end of the session.

Kalsher, M.J., Van Duijne, F., Waters Deppa, S., Mont.Alvão Pontifícia, C., Rother, H.A., Vredenburgh, A.G., Wogalter, M. (2007). An International Perspective on Risk Communications: Adapting to Safety Demands in the Emerging Global Economy. In Proceedings of the Human Factors and Ergonomics Society 51st Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 1403-1405.

Significant differences in the liability systems in the U.S. and other parts of the world, dramatic advances in consumer product technology (and complexity), and the rapid pace of market globalization have converged to create an urgent need for new methods of conveying hazard information to an increasingly diverse universe of product and equipment users worldwide.  Stark differences in languages, cultures and education currently make this a daunting task.  The purpose of this session is to explore alternative ways of thinking about risk communication in an effort to spark new research that will be responsive to the safety demands of the new millennium. To accomplish these objectives, we have assembled a group of international scholars and practitioners who have published and/or worked extensively in the general topic area.  One feature of this panel discussion session that is unique is that each participant will present data relevant to a particular set of risk communication issues in their respective countries.  A synopsis of this work is outlined in the summary that follows.

Vredenburgh, A.G., Kalsher, M.J., & Vredenburgh, M.J. (2006). Evaluating hazard communication of patient medication information sheets for prescription drugs. IEA2006: 16th World Congress on Ergonomics. Elsevier Ltd.

The US Food and Drug Administration requires that pharmacies provide patient medication information (PMI) sheets describing usage and hazard information to recipients of the prescription drugs that they dispense. These PMI sheets are required to be understood at a 6th grade reading level (the standard for patient education materials). All medications have risk associated with their use. It is important for patients, physicians and pharmacists to have enough information to decide whether the benefits of taking a medication outweigh the risks.

Vredenburgh, A.G., Vredenburgh, M.J., & Kalsher, M.J. (2006). Adolescent risk perception and self-protective behavior regarding airsoft and paintball Guns. IEA2006: 16th World Congress on Ergonomics. Elsevier Ltd.

Airsoft and paintball markers (paintball guns) are marketed as toy replicas of real firearms and have become popular worldwide. A survey created for this study consists of 26 items that requested information on demographics, experience using toy guns and perceptions of the dangers of the toy guns. Of the participants 45% had not used an airsoft gun and 55% had. 43% had used a paintball gun and 57% had experienced paintball. 60% had used a BB gun and 40% have not used a BB gun. Of the 40 participants that have used an airsoft, during target practice 41% did not ever wear eye protection. However when they played airsoft with other people 15% still did not ever wear eye protection.

Vredenburgh, A.G. & Zackowitz, I.B. (2006). Warning Expectations. In M. Wogalter (Ed.), The Handbook of Warnings: Design and Use. Chapter 25. Lawrence Erlbaum Zackowitz, Inc., 345-354.

Expectations are beliefs that can influence warning effectiveness. Expectations are related to precautionary intent, and, in turn, precautionary intent is largely a function of a person’s expectations about possible consequences (DeJoy, 1999a). Factors that can influence expectations are analyzed including hazard perception, familiarity, experience, relevance, and personal attitudes and beliefs. These factors and expectations are precursors to how people may behave in hazardous situations. Also addressed is how societal attitudes and marketing can influence expectations. Implications on how warnings can be applied to better influence expectations are discussed.

Vredenburgh, A.G. & Helmick-Rich, J.A. (2006). Extrinsic Non-warning Factors. In M. Wogalter (Ed.), The Handbook of Warnings: Design and Use. Chapter 28. Lawrence Erlbaum Zackowitz, Inc., 373-384.

There are external factors that affect whether well-designed warnings are effective. These extrinsic factors are not related to warning design, in contrast to intrinsic variables that pertain to the design of a warning itself. Some extrinsic factors are person variables such as social influence, personality, and perceptions. Some are environmental factors such as visibility, noise and clutter. This chapter describes how extrinsic factors such as the social and physical environment as well as individual differences in human responses to a warning can affect various effectiveness criteria.

Vredenburgh, A.G., Longden, S., Williams, K.J., & Kalsher, M.J. (2005). Evaluating latex glove container warnings in a realistic setting. International Journal of Industrial Ergonomics, 35, 559-568.

Healthcare workers sometimes develop severe hypersensitivity to products containing latex. This study evaluated three label configurations designed to alert users to the risks of latex exposure. Results included evidence of an industry-wide lack of knowledge regarding latex hypersensitivity.  The explicit warning was most effective in alerting participants to the hazard.

Vredenburgh, A.G. & Zackowitz, I.B. (2005). Human factors issues to be considered by product liability experts. In Y.I. Noy & W. Karwowski (Eds.), Handbook of Human Factors in Litigation. Chapter 26. Boca Raton, FL: CRC Press, 26-1 – 26-11.

In this chapter, we will discuss some product liability issues that human factors experts should consider when investigating accidents that occur when someone is injured while using a consumer product. The objective is to demonstrate how a human factors consultant would evaluate a product liability case. This discussion will include an analysis of product design, effectiveness of warnings and instructions, and the human conduct contribution to these incidents. To demonstrate the evaluation of product liability cases, three case studies will be discussed. One case will describe design issues pertaining to the interaction between a motorcycle fuel valve and fuel gauge. A second case involves the use of barriers on a hot/cold compress. A final example will illustrate how warnings come into play by discussing a case involving latex glove hypersensitivity. Although only these cases are discussed, the analytical approach presented in this chapter can be applied by human factors experts to other products cases.

Vredenburgh, A.G. & Weinger, M.B., (2004). Examination of apparent flaws in the American drug hazard detection, evaluation, and risk communication system. Abstract in the Program of the Second Annual Patient Safety Conference: Making care safer one patient at a time. San Diego, California, 100.

Approximately 100,000 Americans die annually from adverse drug events (ADE). Yet, physicians, pharmacists and patients are often unaware of the risks associated with many medications. Our healthcare system relies on accurate reporting of ADE by clinicians to the pharmaceutical companies, and by the companies to the FDA. The system also relies on pharmaceutical companies providing complete and accurate risk information to clinicians who must then inform their patients. We hypothesize that our system to assess and communicate medication risk is defective and may actually increase the probability of ADE. Conflict of interest is a major problem. Manufacturers want to bring their drugs to market as quickly as possible leading to a bias to study as few patients as necessary to prove a benefit. As a result, most pre-market studies are insufficiently powered to detect less common ADE. Officially sanctioned medication information like the FDA-approved drug package inserts often contain misinformation, outdated information, and omissions. However, the content of these materials, initially prepared by manufacturers, is the result of complex negotiations during the drug approval process. While FDA oversight insures a minimal level of accuracy, anchoring and other biases can be expected given the manufacturer’s financial motivations. Post-market surveillance of drug risks relies primarily on voluntary reporting of ADE. However, voluntary reporting captures only a small proportion of actual ADE for a variety of reasons. Clinicians often have difficulty associating adverse events with specific drugs in individual patients given multipharmacy, underlying disease or other concurrent factors. There are no incentives to report ADE. In fact, there are strong financial, regulatory, and medicolegal disincentives for clinicians, hospitals, and manufacturers. Pharmaceutical sales representatives, known to be the primary source of drug information for about half of all physicians, also have conflicting responsibilities: to sell their drugs and to educate clinicians about those drugs, including risk information. Over-worked clinicians may forget to communicate effectively known risks to patients. These myriad flaws in our drug hazard management and communication system, which interact to increase the probability of ADE, must be addressed.

Vredenburgh, A.G., Longden, S., Williams, K.J., & Kalsher, M.J. (2003). Medical Product Labeling: The evaluation of latex allergy warnings in a realistic setting. In Proceedings of the Human Factors and Ergonomics Society 47th Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 1554-1558.

Through repeated exposure to proteins in latex gloves, healthcare workers sometimes develop a deadly allergic reaction. Although the latex glove industry apparently drafted detailed warnings, none of these actually appeared on gloves boxes. This field study evaluated three label configurations.  The first indicated that the gloves contain natural rubber latex. A second configuration mirrored current labeling.  A third label created for this study comported to existing warnings guidelines (ANSI).   Participants examined one of the three boxes and were then asked to complete a questionnaire gauging their opinions and perceptions regarding the labeling. Results showed that the ANSI warning was rated as more noticeable and more effective than the other label configurations.  Well-designed instructional warnings can be an effective method of informing workers of the significant risks associated with exposure to latex.  The informational component of warnings labeling is particularly critical for apparently benign products that bear a hidden hazard.

Vredenburgh, A.G., & Zackowitz, I.B. (2001). Evaluating the effectiveness of a pictorial-only warning on a trolley coupler. In Proceedings of the Human Factors and Ergonomics Society 45th Annual Meeting. Santa Monica, CA: Human Factors and Ergonomics Society, 848-851.

Warnings with pictorial symbols are often used because symbols tend to be attention getting. If a text message included in a warning detains readers in a hazardous location, this text message may keep readers in harm’s way. Therefore, warnings comprised only of pictorials may be the best solution in some situations. The purpose of this study was to evaluate a pictorial as the sole source of warning information. Eighty-five participants were asked about their comprehension of a warning symbol, both without and with contextual information. Results indicated that 96% of participants over 16 years old were able to comprehend the warning, which exceeds the ANSI standard of 85% symbol comprehension rate.

Vredenburgh, A.G., & Cohen, H.H. (1995). High risk recreational activities: Skiing and scuba − What predicts compliance with warnings. International Journal of Industrial Ergonomics, 15, 123-128. Abstract reprinted (1996), Journal of Safety Research, 27(2), 134-135.

People tend to read warnings if they perceive an activity or product to be dangerous or if they are less familiar with it. In addition to examining whether warnings have been read, the current study also addresses user compliance by surveying people immediately after they have completed a high-risk recreational activity (either skiing or scuba diving). This study asked three questions: Does the perception of danger affect the reading of, and compliance with warnings?; does familiarity with an activity affect reading and compliance?; and is there a difference between men and women in the way they respond to these questions and others regarding high-risk activities? The perception of danger increased the reported compliance with warnings. While familiarity with a particular activity increased the reading of warnings, familiarity did not increase reported compliance with warnings. Men were more likely to participate in high-risk sports; there were no other significant sex differences.

Vredenburgh, A.G., & Cohen, H.H. (1995). Does culture affect risk perception?: Comparisons among Mexicans, African-Americans, Asians, and Caucasians. In Proceedings of the 39th Annual Meeting of the Human Factors and Ergonomics Society. Santa Monica, CA: Human Factors and Ergonomics Society, (2), 1015-1019. Abstract reprinted (1996), Journal of Safety Research, 27(2), 272.

Vredenburgh, A.G. & Cohen, H.H. (1993). Compliance with warnings in high-risk recreational activities: Skiing and scuba. In Proceedings of the 37th Annual Meeting of the Human Factors and Ergonomics Society. Santa Monica, CA: Human Factors and Ergonomics Society (2), 945-949.