The Journal of Extension -

April 2016 // Volume 54 // Number 2 // Tools of the Trade // v54-2tt5

Food Safety Posters for Safe Handling of Leafy Greens

This article describes food safety educational tools depicting safe handling of leafy greens that are available as downloadable posters to Extension educators and practitioners ( Nine visual-based minimal-text colored posters in English, Chinese, and Spanish were developed for use when formally or informally educating foodservice workers about safely handling leafy greens. A three-phase methodology included the use of expert knowledge, microbial sampling, and observational study in Iowa and Kansas foodservice operations. Use of the posters was shown to have positive impacts on both microbial levels and food safety behaviors, suggesting that the posters can be useful tools for Extension personnel.

Lakshman Rajagopal
Associate Professor
Department of Apparel, Events, and Hospitality Management
Iowa State University
Ames, Iowa

Susan W. Arendt
Associate Professor
Department of Apparel, Events, and Hospitality Management
Iowa State University
Ames, Iowa

Angela M. Shaw
Assistant Professor/Extension and Outreach
Department of Food Science and Human Nutrition
Iowa State University
Ames, Iowa

Catherine H. Strohbehn
Adjunct Professor/Extension and Outreach
Department of Apparel, Events, and Hospitality Management
Iowa State University
Ames, Iowa

Kevin L. Sauer
Associate Professor
Department of Human Nutrition
Kansas State University
Manhattan, Kansas


Safe Handling of Leafy Greens

Leafy greens have been implicated in a large number of foodborne illness outbreaks. The Centers for Disease Control and Prevention found that 46% of reported foodborne illnesses were linked to fresh produce and nuts, with 22% linked to leafy greens (Painter et al., 2013). Contamination of leafy greens can happen at any point from farm to fork, at home, or in foodservice. With almost half of every American food dollar spent on food prepared away from home (U.S. Department of Agriculture, Economic Research Service, 2014) and 44.8% of dark leafy vegetable and lettuce consumption taking place away from home (U.S. Department of Agriculture, Economic Research Service, 2014), it is important that those working in retail food establishments understand safe handling of fresh leafy greens.

Use of Visual-Based Tools for Food Safety Training

Increases in immigration and globalization have increased ethnic diversity in the United States. This diversity can be seen in the general population and in the restaurant industry, which employs more minorities than any other industry (National Restaurant Association, 2012). A diverse workforce results in variations in food handling attitudes, behaviors, and practices that can impact food safety. Diversity in the workforce also may be exhibited in differences in literacy levels. Further, generational differences in the workforce, resulting from the influx of Generations X and Y, have led to the need for innovative and quick learning strategies (Kutner, Greenberg, Jin, & Paulsen, 2006). Consistent communication of messages and provision of resources and tools to workers by foodservice managers and supervisors are critical components for safe food handling practices to occur in the workplace (Arendt & Sneed, 2008; Ellis, Arendt, Strohbehn, Meyer, & Paez, 2010; Roberts, Arendt, Strohbehn, Ellis, & Paez, 2012). Use of minimal-text visuals helps convey critical food safety messages to Spanish-speaking workers (Justen, Haynes, VanDerZanden, & Grudens-Schuck, 2011; Rajagopal, 2012, 2013; Rajagopal & Strohbehn, 2011). Use of passively delivered educational intervention has been successful in improving food safety knowledge among restaurant food handlers (Chapman, Eversley, Fillion, MacLaurin, & Powell, 2010; Dworkin, Panchal, & Liu, 2012).


A university's Institutional Review Board for Human Subjects Research approved the study described herein, which employed a three-phase design to develop and assess the effectiveness of food safety messaging on leafy greens handling practices in retail foodservice establishments in Iowa and Kansas.

Phase One

Observational data (based on observations of both employees and operations), microbial data (relevant to both leafy greens and contact surfaces), and interview data were collected and analyzed from a convenience sample of foodservice operations (n = 8). Validated assessment forms (Sneed, Strohbehn, & Gilmore, 2004; Strohbehn, Sneed, Paez, & Meyer, 2008) were used to record data about operational aspects (e.g., food safety messaging, food handling procedures, and facilities and equipment) and employee behavior when preparing leafy greens. An interview guide was developed and used to interview employees (n = 16) about their observed food handling behaviors.

Phase Two

Visual-based minimal-text food safety messaging posters (intervention) were developed and evaluated by (a) a panel with expertise in food safety and/or foodservice operations (n = 5), (b) foodservice workers (n = 8), (c) foodservice managers (n = 4), and (d) undergraduate students (n = 120). Feedback obtained from the evaluators was used to improve the posters prior to dissemination to each of the participating sites. See Figure 1 for examples of the posters.

Figure 1.
Examples of Visual-Based Tools Developed for Safe Handling of Leafy Greens

Phase Three

The effectiveness of the intervention (i.e., food safety messaging poster implementation) was assessed by collecting observational data, microbial data, and interview data during postintervention visits at 1 and 3 months. Comparisons were made between preintervention (phase one) data and postintervention (phase three) data to assess effectiveness of the food safety messaging intervention.


The following posters were developed:

  • My Health Is In Your Hands
  • Food Safety Is In MY Hands
  • I Won't Cross-Contaminate By Doing This
  • The Yuck Stops Here!
  • Prevent Cross-Contamination: Keep Hands Clean! Do Not Touch
  • I Make The Difference! Whole Leafy Greens
  • Whole Leafy Greens: Dos and Don'ts
  • I Make the Difference! Bagged Leafy Greens
  • Bagged Leafy Greens: Dos and Don'ts

Microbial analyses of leafy greens and leafy greens contact surfaces after implementation of the posters in foodservice establishments showed decreases in microbial loads on leafy greens and leafy greens contact surfaces (Roy et al., 2015). Abdelmassih et al. (2015) suggested that these posters can have a positive effect on safe handling of leafy greens but noted that commitment from management is required to make foodservice workers part of the decision-making process when developing food safety messages and identifying locations for posting. That research team further acknowledged that no single method of training can improve food handling behaviors. The study reported here provides further support that the use of multiple training methods, both formal (e.g., lecture) and informal (e.g., displaying posters in strategic locations in the foodservice establishment), influences safe handling of leafy greens.


Evaluation of the effectiveness of the posters on improving safe handling of leafy greens in foodservice establishments showed improvements in leafy greens handling practices and reduction in microbial loads. The posters can be used by Extension educators in training foodservice entrepreneurs and their staff, as well as consumers, about safely handling leafy greens. The posters can improve outreach efforts to include community stakeholders from diverse backgrounds.

Further, Extension educators can connect with college and university instructors to make them aware of these tools as a resource for their classrooms, thus reaching future generations of the foodservice workforce. Education on safe handling of leafy greens can help mitigate the incidence of foodborne illness and deaths; availability of tools to improve learning among diverse audiences about safe handling of leafy greens can further lower risk of product contamination.


This project was funded by United States Department of Agriculture, National Institute of Food and Agriculture (AFRI #2013-68003-2194).


Abdelmassih, K., Arendt, S. W., Strohbehn, C. H., Rajagopal, L., Sauer, K. L., & Shaw, A. M. (2015). Evaluating the impact of food safety messaging posters on observed employee food safety behavior: A mixed-methods approach. Manuscript under review.

Arendt, S. W., & Sneed, J. (2008). Employee motivators for following food safety practices: Pivotal role of supervision. Food Protection Trends, 28(10), 704–711.

Chapman, B., Eversley, T., Fillion, K., MacLaurin, T., & Powell, D. (2010). Assessment of food safety practices of food service food handlers (risk assessment data): Testing a communication intervention (evaluation of tools). Journal of Food Protection, 73(6), 1101–1107.

Dworkin, M. S., Panchal, P., & Liu, L. (2012). The CHEF project: Results of a randomized bilingual dual format passive restaurant food handler educational intervention in Chicago. Food Protection Trends, 32(10), 564–573.

Ellis, J., Arendt, S., Strohbehn, C., Meyer, J., & Paez, P. (2010). Varying influences of motivation factors on employees' likelihood to perform safe food handling practices because of demographic differences. Journal of Food Protection, 73, 2065–2071.

Justen, E., Haynes, C., VanDerZanden, A. M., & Grudens-Schuck, N. (2011). Insights from Spanish-speaking employees in the Iowa horticultural industry. Journal of Extension [online], 49(6) Article 6RIB8. Available at:

Kutner, M., Greenberg, E., Jin, Y., & Paulsen, C. (2006). The health literacy of America's adults: Results from the 2003 National Assessment of Adult Literacy. NCES 2006-483. National Center for Education Statistics.

National Restaurant Association. (2012). Restaurant industry fact sheet. Retrieved from

Painter, J. A., Hoekstra, R. M., Ayers, T., Tauxe, R. V., Braden, C. R., Angulo, F. J., & Griffin, P. M. (2013). Attribution of foodborne illnesses, hospitalizations, and deaths to food commodities by using outbreak data, United States, 1998–2008. Emerging Infectious Diseases, 19(3), 407. doi: 10.3201/eid1903.111866

Rajagopal, L. (2012). Use of visuals as a method for food safety education in Southern Iowa. Journal of Extension [online], 50(2) Article 2RIB6. Available at:

Rajagopal, L. (2013). Educating immigrant Hispanic foodservice workers about food safety using visual-based training. Journal of Extension [online], 51(2) Article 2FEA8. Available at:

Rajagopal, L., & Strohbehn, C. H. (2011). I'm Gloving It!—Development of a minimal-text visual to educate college and university foodservice workers about glove use. Food Protection Trends, 33(5), 315–324.

Roberts, K., Arendt, S., Strohbehn, C., Ellis, J., & Paez, P. (2012). Educating future managers to motivate employees to follow food safety practices. Journal of Foodservice Management and Education, 6(1), 1–8.

Roy, A., Shaw, A., Rajagopal, L., Strohbehn, C. H., Arendt, S. W., & Sauer, K. L. (2015). Use of minimal-text posters to improve the microbial status of leafy greens and food contact surfaces in foodservice sites serving older adults. Manuscript under review.

Sneed, J., Strohbehn, C., & Gilmore, S. A. (2004). Food safety practices and readiness to implement HACCP programs in assisted-living facilities in Iowa. Journal of the American Dietetic Association, 104(11), 1678–1683. doi:10.1016/j.jada.2004.08.031

Strohbehn, C., Sneed, J., Paez, P., & Meyer, J. (2008). Hand washing frequencies and procedures used in retail food services. Journal of Food Protection, 71(8), 1641–1650.

U.S. Department of Agriculture, Economic Research Service. (2014). Food-away-from-home. Retrieved from