Studies on Restaurant Food Handling and Food Safety Practices
This page lists completed EHS-Net food safety studies with a focus on restaurant food handling/food safety practices.
Beef Grinding Logs Study
Objective: To describe recordkeeping practices of beef grinding activities in retail establishments.
Study Results: Ground beef has been implicated as a transmission vehicle in foodborne outbreaks of infection with pathogens such as Escherichia coli O157:H7 and Salmonella. During outbreak investigations, traceback of contaminated beef to the producing facility is often unsuccessful because of inadequate recordkeeping at retail establishments that grind beef products. We conducted a survey in three EHS-Net states to describe beef grinding and recordkeeping practices at retail establishments. In each establishment that maintained grinding logs, three randomly selected records were reviewed to determine whether important data elements for traceback investigations were recorded. One hundred twenty-five stores were surveyed, of which 60 (49%) kept grinding logs, including 54 (74%) of 73 chain stores and 6 (12%) of 51 independent stores. One hundred seventy-six grinding records from 61 stores were reviewed. Seventy-three percent of the records included the establishment code of the source beef, 72% included the grind date and time, and 59% included the lot number of the source beef. Seventy-five percent of records noted whether trimmings were included in grinds, and 57% documented cleanup activities. Only 39 (22%) records had all of these variables completed. Of stores that did not keep grinding logs, 40% were unaware of their purpose. To facilitate effective and efficient traceback investigations by regulatory agencies, retail establishments should maintain records more detailed and complete of all grinding activities.
Publication: Gould LH, Seys S, Everstine K, Norton D, Ripley D, Reimann D, et al. Recordkeeping practices of beef grinding activities at retail establishments. [PDF - 283 KB] J Food Prot. 2011;74(6):1022-4.
Study findings in plain language: Beef grinding records kept by retail stores.
Egg-Handling Practices Study
Objective: To identify the prevalence of high-risk egg-handling practices and establishment policies in restaurants that serve breakfast all day.
Study Results: Interviews and observations conducted in restaurants that prepare eggs revealed that risk egg handling practices were common. Fifty-four percent of restaurants pooled raw shell eggs not intended for immediate service. These pooled eggs were held a median of 4 hours for scrambled eggs, 5.5 hours for omelets, and 6 hours for pancakes and French toast. Nearly 26% of restaurants reported storing eggs at room temperature. Employees reported sanitizing utensils used to prepare eggs less than once every 4 hours in 42% of restaurants. However, eggs were generally cooked to 72 to 83ºC, which is above the recommended final cook temperature of 63 to 68ºC.
Publication: Lee R, Beatty M, Bogard A, Esko M, Angulo F, Selman C, EHS-Net Working Group. Prevalence of high-risk egg-preparation practices in restaurants that prepare breakfast egg entrees: An EHS-Net study. [PDF - 178 KB] J Food Prot. 2004;67:1444-50.
Study findings in plain language: How restaurants prepare eggs.
Food Cooling Practices Study
Objective: To collect descriptive data on food cooling practices in restaurants.
Study Results: Improper food cooling practices are a significant cause of foodborne illness, yet little is known about restaurant food cooling practices. This study was conducted to describe food cooling practices in restaurants and assess the frequency with which restaurants meet U.S. Food and Drug Administration (FDA) cooling recommendations. We conducted interviews with food managers and observed food cooling practices in 420 restaurants in nine EHS-Net sites. The data indicate that many restaurants are not meeting FDA recommendations concerning cooling. Although most restaurant kitchen managers said that they have formal cooling processes (86%) and provide training to food workers on proper cooling (91%), many managers said that they do not have tested and verified cooling processes (39%), do not monitor time or temperature during cooling processes (41%), or do not calibrate thermometers used for monitoring temperatures (15%). Indeed, 86% of managers reported cooling processes that did not incorporate all FDA-recommended components. Additionally, restaurants do not always follow recommendations concerning specific cooling methods, such as refrigerating cooling food at shallow depths, ventilating cooling food, providing open-air space around the tops and sides of cooling food containers, and refraining from stacking cooling food containers on top of each other. Data from this study could be used by food safety programs and the restaurant industry to target training and intervention efforts concerning cooling practices. These efforts should focus on the most frequent poor cooling practices, as identified by this study.
Publication: Brown LG, Ripley D, Blade H, Reimann D, Everstine K, Nicholas D, et al. Restaurant food cooling practices. [PDF - 435 KB] J Food Prot. 2012;75(12):2172-8. [EHS-Net Working Group]
Study findings in plain language: How restaurants cool food.
Food Workers’ Food Preparation Practices Focus Group Study
Objective: To evaluate behavioral factors, barriers, and motivations that influence safe food-handling practices in food-service establishments.
Study Results: In focus groups on food workers’ food safety practices, some food workers reported unsafe food preparation practices, such as inappropriate glove use and not checking the temperatures of cooked, reheated, and cooled foods. Most workers, however, reported safe practices (e.g., washing their hands after preparing raw meat). Workers identified a number of factors that impacted their ability to prepare food safely, including time pressure; structural environments, equipment, and resources; management and coworker emphasis on food safety; worker characteristics; negative consequences for those who do not prepare food safely; food safety education and training; restaurant procedures; and glove and sanitizer use. Results suggest that food safety programs need to address the full range of factors that impact food preparation behaviors.
Publication: Green L, Selman C. Factors impacting food workers’ and managers’ safe food preparation practices: a qualitative study. [PDF - 244 KB] Food Prot Trends. 2005;25:981-90.
Study findings in plain language: Factors affecting safe food preparation by food workers and managers.
Food Workers’ Food Preparation Practices Population Study
Objective: To determine self-reported prevalence of food service workers’ safe and unsafe food preparation practices at the population level.
Study Results: In a telephone survey of randomly selected food service workers, respondents commonly reported risky food preparation practices. Respondents said that at work they did not always wear gloves while touching ready-to-eat (RTE) food (60%), did not always wash their hands or change their gloves between handling raw meat and RTE food (23% and 33%), did not use a thermometer to check food temperatures (53%), and had worked while sick with vomiting or diarrhea (5%). Workers responsible for food preparation reported washing their hands and wearing gloves when handling RTE food more often than workers not responsible for food preparation. Workers who cooked reported changing their gloves more often than workers who did not cook. Workers in chain restaurants more frequently reported using thermometers than workers in independently owned restaurants.
Publication: Green L, Selman C, Banerjee A, Marcus R, Medus C, Angulo FJ, et al. Food service workers’ self-reported food preparation practices: an EHS-Net study. Int J Hyg Environ Health. 2005;208(1–2):27-35.
Study findings in plain language: Food safety practices of restaurant workers.
Ground Beef Handling Practices Study
Objective: To evaluate ground beef handling practices and the use of irradiated ground beef in restaurants.
Study Results: Interviews and observations in restaurants that handle raw ground beef revealed that risky ground beef handling practices were pervasive in restaurants. Sixty-four percent of restaurants reported they never took the temperature of fresh ground beef upon delivery, and 50% reported they never took the final cook temperature of hamburgers. Observations indicated that in 49% of restaurants, hands were not washed after handling raw ground beef, and in 60% of restaurants, hands were wiped on wiping cloths or aprons after handling raw ground beef. Only 1% of restaurants reported always or sometimes purchasing irradiated ground beef, and 29% reported that they had never heard of irradiated ground beef. These results indicate the need for food worker educational campaigns that focus on hand hygiene, avoiding cross-contamination, and verification of the final cook temperatures of ground beef.
Poster presentation: Bogard AK, Marcus R, Ripley D, Stigger T, Radke V. Prevalence of risky food-handling practices in restaurants that serve hamburgers. [PDF - 206 KB] Presented at the National Environmental Health Association 70th Annual Education Conference and Exhibition; 2006 June 25-29, San Antonio.
Objective: To describe restaurant food workers' hand hygiene practices and identify factors associated with safe hand hygiene practices.
Study Results: Observations of workers preparing food at work (n=321) indicated that workers engaged in approximately 8.6 activities per hour for which hand washing is recommended. However, workers made hand washing attempts in only 32% of these activities and washed their hands appropriately in only 27% of these activities. Attempted and appropriate hand washing rates were significantly higher in conjunction with food preparation than other activities (e.g., handling dirty equipment). Attempted and appropriate hand washing rates were significantly lower when gloves were worn than when gloves were not worn. Hand washing and glove use were more likely to occur when workers were not busy. Hand washing was more likely to occur in restaurants that provided food safety training, with more than one hand sink, and with a hand sink in the worker’s sight. Glove use was more likely to occur in chain restaurants and in restaurants with glove supplies in food preparation areas. These findings suggest that food worker hand washing practices need to be improved, glove use may reduce hand washing, and restaurants should consider reorganizing their work activities to reduce the need for hand washing. Findings also indicate that several factors are related to hand hygiene practices and support suggestions that food worker hand hygiene improvement requires multidimensional programs.
Publication: Green LR, Radke V, Mason R, Bushnell L, Reimann DW, Mack J, et al. Factors related to food worker hand hygiene practices. [PDF - 489 KB] J Food Prot. 2007;70(3):661-6.
Study findings in plain language: Food worker handwashing and restaurant factors.
Publication: Green LR, Selman CA, Radke V, Ripley D, Mack JC, Reimann DW, et al. Food worker hand washing practices: an EHS-Net observation study. [PDF - 288 KB] J Food Prot. 2006;69(10):2417-23.
Study findings in plain language: Food worker handwashing and food preparation.
Ill Food Worker Study
Objective: To describe the frequency with which food workers work while experiencing vomiting or diarrhea and factors associated with working with these symptoms.
Study Results: Transmission of pathogens from food workers to the food they handle is implicated as a contributing factor in approximately 20% of foodborne illness outbreaks. However, little is known about the characteristics of workers who work with a foodborne illness, or the characteristics of their restaurant environment that might promote or prevent such risky behavior. This study was designed to collect information on these topics. We conducted interviews with food workers (n=491) and their managers (n=387) in restaurants in the nine EHS-Net states. Fifty-eight (11.9%) workers said they had worked while suffering vomiting or diarrhea on two or more shifts in the previous year. Factors associated with workers having worked while experiencing vomiting or diarrhea were (i) high volume of meals served, (ii) lack of policies requiring workers to report illness to managers, (iii) lack of on-call workers, (iv) lack of manager experience, and (v) workers of the male gender. Our findings suggest that policies that encourage workers to tell managers when they are ill and that help mitigate pressures to work while ill could reduce the number of food workers who work while experiencing vomiting or diarrhea.
Publication: Sumner S, Brown LG, Frick R, Stone C, Carpenter LR, Bushnell L, et al. Factors associated with food workers working while experiencing vomiting or diarrhea. [PDF - 190 KB] J Food Prot. 2011;74(2):215-20.
Study findings in plain language: Food workers working when they are sick.
Tomato-Handling Practices Study
Objective: To identify the types of tomatoes used in restaurants, describe tomato-handling practices, and to identify factors associated with safer tomato-handling practices.
Study Results: In recent years, multiple Salmonella outbreaks have been associated with fresh tomatoes. Investigations have indicated that tomato contamination likely occurred early in the farm-to-consumer chain, although tomato consumption occurred mostly in restaurants. Researchers have hypothesized that tomato-handling practices in restaurants may contribute to the occurrence of these outbreaks. However, little empirical data exists on how restaurants handle tomatoes. Thus, this study examined restaurants’ tomato-handling practices. Environmental Health Specialists Network (EHS-Net) members conducted an observation of tomato-handling practices in 449 restaurants. The data indicated that handling tomatoes appropriately posed a challenge to many restaurants. Produce-only cutting boards were not used in 49% of tomato cutting observations and gloves were not worn in 36% of observations. Although tomatoes were washed under running water, as recommended, in most (82%) washing observations, tomatoes were soaked in standing water, a practice not recommended by FDA, and the water-tomato washing temperature differential did not meet FDA guidelines in 21% of washing observations. About half of all batches of cut tomatoes in holding were above 41º F, the temperature recommended by the FDA. Additionally, the maximum holding time for most (73%) cut tomatoes held above 41º F exceeded the FDA recommended holding time of four hours for unrefrigerated tomatoes (i.e., tomatoes held above 41º F). The information provided by this study can be used to inform tomato-associated illness outbreak prevention and intervention efforts.
Publication: Kirkland E, Green LR, Stone C, Reimann D, Nicholas D, Mason R, et al. Tomato handling practices in restaurants. [PDF - 109 KB] J Food Prot. 2009;72(8):1692-8.
Study findings in plain language: How restaurants handle tomatoes.