Consumers are increasingly looking for convenient services¹ that help them plan and prepare delicious and healthy meals. Meal kits are one example of a service that has risen to meet this need, from their introduction in Sweden in 2007 to the present, where over 150 companies offer meal kits in the U.S. alone.² Consumers report that portion control, reduced food waste, a variety of food options, more meaningful family meal times, and the use of local food are key benefits of using meal kits.³ Consumers were also drawn to meal kits in the face of restaurant closures during the height of the COVID-19 pandemic.

Meal kits use a direct-to-consumer model of delivering perishable, pre-measured ingredients for pre-selected recipes that are then used to prepare and cook meals at home. Meal kits are likely to contain a variety of foods that, in the absence of proper refrigeration, present a high risk for bacterial growth, such as raw meat products, eggs, and dairy. Other ingredients, such as raw produce, may be contaminated by pathogenic bacteria at the source facility or are subject to cross-contamination during processing alongside raw meat ingredients. Meal kit manufacturers also often repackage ingredients into plain or branded packaging, which can result in the consumption of unexpected ingredients or allergens. The combination of these considerations is unique to meal kit services and has particular implications with regard to food safety.

Meal Kit Recalls and Outbreaks

Meal kits have been involved in several food safety recalls around the world. Not all of these recalls have resulted in illnesses confirmed to be connected to the recall, including a 2018 recall of raw ground beef used in a meal kit due to the detection of E. coli,⁴ and Salmonella detected in a meal kit ingredient containing red chili in 2019.⁵ However, outbreaks of foodborne illness have also been traced back to meal kits, including 268 people falling ill in 2019 due to Clostridium perfringens that was traced back to a ready-to-heat minced meat sauce distributed through a meal kit in Denmark,⁶ and a 2021 Salmonella outbreak that affected over 600 people in the U.S. due to contaminated onions⁷ that were used in multiple meal kit brands and sold independently.

More recently, in 2022, raw ground beef that was distributed through meal kits was identified as the probable source of an E. coli outbreak that caused illness in seven people in the U.S.⁸ Another meal kit product, a frozen package called "French Lentil + Leek Crumble," was linked to nearly 500 reported cases of gastrointestinal illness and impaired liver function.⁹ While the cause of this outbreak is unknown, preliminary investigations have suggested that tara flour used in this product was the source of the adverse health outcomes.¹⁰

Regulation and Oversight

It is evident that meal kits have the potential to, and have, caused outbreaks of foodborne illness. However, as the widespread use of meal kits is relatively new, regulations and oversight have not kept up in many jurisdictions. In the lack of specific regulations, businesses that are involved in meal kits have a responsibility to minimize food safety risks. While businesses must abide by applicable laws and regulations in their jurisdiction, some additional best practices are more tailored to the unique risks present in meal kit operations. One such example is the guidance document prepared by the Conference for Food Protection for direct-to-consumer and third-party delivery food services.¹¹ This extensive document contains best practices for the prevention of biological, physical, and chemical contamination and discusses risk assessment, preventive controls, validation and verification procedures, packaging, temperature control, storage, and recalls.

Food safety risks can also be managed within a Hazard Analysis and Critical Control Points (HACCP)-based approach that evaluates the food safety risks throughout the lifecycle of the product and developing control points at each step of the process that reduce those risks. The following section of this article discusses some best practices that can be included in a HACCP-based food safety plan aimed at reducing risks specific to meal kits.

A HACCP Approach to Meal Kit Safety

While variation exists in manufacturing processes between meal kit services, most have similar steps involved including ingredient sourcing, food processing, food packaging and labeling, storage, transportation, and consumer handling. Each of these stages should be included in a HACCP-based food safety plan.

While other hazards may be present and need to be accounted for, the main risks to food safety that require particular attention in the case of meal kits include cross-contamination, temperature control, and allergens.

Cross-Contamination

Cross-contamination can occur with biological risks, such as pathogenic bacteria or viruses, or with chemical risks, such as chemical contaminants or allergens. It is a particular challenge in the case of meal kits since multiple food products, which may be sourced from multiple suppliers, may be processed in the same facility and are then packed into the same box. Meal kits often contain ingredients in the same box that are to be cooked and eaten raw, introducing the risk of cross-contamination of potentially harmful pathogens that will not be destroyed in the cooking process before consumption.

Cross-contamination can occur at other stages of a meal kit, as well. Once all the ingredients are inside the meal kit, proper packaging is necessary to ensure that ingredients are kept separate, especially high-risk foods such as raw meat, poultry, eggs, seafood, and dairy. This packaging must be able to retain its integrity throughout the transport process, which may include rough handling. Finally, customers should be provided with education on how to unpack their meal kits to reduce cross-contamination, as well as on safe food handling techniques to use while preparing recipes.

Best practices to reduce cross-contamination include:

• Ingredient sourcing

1. Verifying the food safety protocols from all ingredient suppliers

1. Keeping raw meats separate from ready-to-eat foods (e.g., separate chopping board, utensils, equipment, and storage areas)
2. Implementing stringent worker hygiene protocols (e.g., handwashing)
3. Implementing cleaning and sanitizing protocols for food contact surfaces

1. Ensuring that outer packaging can withstand transport and handling, and protects the ingredients from damage
2. Developing cleaning and sanitization protocols for outer packaging if it is reusable (i.e., returned by customer)
3. Ensuring that packaging materials are stored separately from foods so that they do not become contaminated before use
4. Packing ingredients separately from each other
5. Using additional packaging within the meal kit to isolate high-risk foods (such as raw meat, eggs, or dairy) from foods that are ready to eat (e.g., vegetables, sauces, or condiments)
6. Ensuring the integrity of coolant packs, as melting or leakage may facilitate cross-contamination
7. Ensuring that any reusable coolant materials (e.g., ice packs) are cleaned and sanitized before reuse

1. Ensuring that general food safety instructions, like proper handwashing and preventive cross-contamination methods, are included in the box, on the product website, or over email
2. Identifying on the label which products to store separately
3. Providing information to customers on how long is safe to keep each ingredient before it spoils, either as a pamphlet, through email, or by adding a "use by" label to each ingredient.

Temperature Control

Temperature maintenance of the ingredients is essential for determining the risk of microbial contamination, as uncooked and raw foods must be kept at temperatures below 39 °F (or below 0 °F, if frozen) to prevent bacterial growth. This can be a particular challenge during meal kit delivery, as meal kits have been found to reach unsafe temperatures at the time of delivery^12,13 or soon after.¹⁴

Meal kits may spend days in transport and hours at the point of delivery before being opened by the consumer. The time that the proper temperature within the meal kit can be maintained is impacted by a number of factors, including the end-to-end delivery time of the meal kit, the packaging materials, the transport conditions, and the conditions at delivery. Proper packaging and transportation and delivery protocols are critical to ensuring that a safe temperature is maintained and that the ingredients within the meal kit are kept from spoiling.

Best practices for maintaining proper temperature control include:

• Packaging

1. Using outer packaging that acts as an insulator, or include an insulated thermal liner
2. Using inner materials (e.g., paper, bubble wrap) to fill voids in the package to help with insulation (dunnage)
3. Choosing a type of coolant that meets the refrigeration needs of the meal kit (consider outer packaging, presence of dunnage, initial temperature of the ingredients, expected transit time, temperature during transit, seasonality); coolant options may include ice packs, frozen gel packs, or dry ice
4. Developing procedures to check that ingredients are at the required temperature before packing
5. If ingredients requiring different temperatures are present, using packaging to create a cold and/or frozen zone within the meal kit to separate those items from other ingredients that may spoil at lower temperatures
6. Using vacuum-sealed or modified atmosphere packaging (MAP) to further limit the growth of harmful bacteria
7. Using time-temperature indicators (TTIs) on the packaging that change color to provide a visual alert for consumers when ingredients have been exposed to unsafe temperatures for a certain amount of time

1. Verifying temperature controls using "worst-case scenarios" to ensure that temperatures can account for variability and are maintained even after the longest possible delivery time
2. Developing procedures for scenarios that may compromise temperature control (e.g., transport route disruptions, equipment breakdown, power outages, emergency scenarios such as floods or fires)
3. Working with delivery companies to restrict the longest possible delivery time, such as by only delivering to specified postal codes or upgrading to same-day or overnight delivery
4. Working with delivery company partners to implement procedures for handling perishable products, such as limiting the time that truck doors are left open during deliveries
5. For long-distance delivery, considering specialized transport such as refrigerated trucks
6. Implementing procedures in the case of a non-delivery (i.e., appropriate storage options if a delivery is to be re-attempted)

1. Ensuring that customers are provided with a date and time to expect their delivery so that they can receive the delivery directly or make other arrangements to receive the package
2. Working with customers to ensure that the meal kit can be dropped off in a shaded location or that someone will be home to receive and unpack the ingredients
3. If delays in delivery occur, providing real-time updates on the expected arrival time of the meal kit
4. Depending on the length of the delay, providing information on which products may need to be discarded if the meal kit was delivered past the expected temperature maintenance window of the included ingredients
5. Including "perishable" labeling on the exterior of the box for customers who may not be aware of the contents (e.g., delivery accepted by another household member, meal kit sent as a gift)
6. Providing temperature maintenance education to consumers, including how to check the temperature of the kit upon opening and the importance of prompt and proper storage of perishable ingredients
7. If TTIs are used, providing information on how to read the indicators and what to do if a temperature breach occurs.

Allergens

Allergens and unexpected food ingredients are of particular concern in meal kits, as the components of a meal kit are often repackaged in plain or rebranded packaging as they are portioned for each recipe. While meal kit businesses must follow allergen labeling regulations in their jurisdiction, allergen labeling and sanitation controls to prevent cross-contamination must also be addressed in a food safety plan. Preventive controls should be used to control for the most prevalent food allergens (milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soybeans) and, where possible, also include less common allergens (such as sesame).

Best practices for allergen control include:

• Ingredient sourcing

1. Ensuring that suppliers follow proper food safety procedures and provide documentation of any possible cross-contamination with allergens
2. Communicating any changes in ingredient sourcing that result in an ingredient that was previously allergen-free to now having a risk of cross-contamination to customers

1. Where possible, processing common allergen ingredients in a separate area to prevent cross-contamination
2. Allocating specific equipment and utensils to be used with ingredients containing the allergen

1. Ensuring that packaging is kept free from cross-contamination with allergens
2. Including a double layer of packaging around ingredients containing an allergen
3. Packaging allergens in a separate area or bag within the meal kit

1. Providing a mechanism for customers to identify allergies at the time of ordering, and alerting the customer if a selected product contains that allergen
2. Including clear ingredient labels on all ingredients that include any risk of exposure to an allergen.

Takeaway

Meal kits are an innovative way for customers to make convenient and healthy meals. The rapid growth of meal kit delivery services has meant that, in some cases, regulations have not yet adapted to include the unique food safety challenges that take place throughout each stage of a meal kit supply chain. However, meal kit businesses can still manage food safety risks using a HACCP-based approach to address food safety hazards, including those that are particularly important in the context of meal kits, such as cross-contamination, temperature control, and allergens. Implementing best practices to reduce these risks throughout the lifecycle of a meal kit—from sourcing the ingredients to the moment they are unpacked and prepared by the customer—can help prevent the kinds of foodborne illness outbreaks that have been linked to meal kits.

References

1. Hertz, F. D. and B. Halkier. "Meal box schemes a convenient way to avoid convenience food? Uses and understandings of meal box schemes among Danish consumers." Appetite 114 (July 1, 2017): 232–239. https://pubmed.ncbi.nlm.nih.gov/28315421/.
2. Scalco, D. "The History and Future of Meal Kits." FoodBoxHQ. April 11, 2019. https://foodboxhq.com/blog/history-future-of-meal-kits/.
3. Fraser K., P. Love, K. J. Campbell, K. Ball, and R. S. Opie. "Meal kits in the family setting: Impacts on family dynamics, nutrition, social and mental health." Appetite 169 (February 1, 2022). https://pubmed.ncbi.nlm.nih.gov/34801628/.
4. Food Safety News. "Ground beef for meal-kit company recalled after E. coli test." March 19, 2018. https://www.foodsafetynews.com/2018/03/ground-beef-for-meal-kit-company-recalled-after-e-coli-test/.
5. Canadian Food Inspection Agency. "Food Recall Warning—Red Chili Ingredient included in certain Hello Fresh brand and Chefs Plate brand Meal Kits recalled due to Salmonella." January 21, 2019. https://inspection.canada.ca/food-recall-warnings-and-allergy-alerts/2019-01-21/eng/1548130312229/1548130314953.
6. Food Safety News. "Outbreaks down but illnesses up for Denmark." September 26, 2020. https://www.foodsafetynews.com/2020/09/outbreaks-down-but-illnesses-up-for-denmark/.
7. Centers for Disease Control and Prevention. "Salmonella Outbreak Linked to Onions: Investigation Details." February 2, 2022 (latest update). https://www.cdc.gov/salmonella/oranienburg-09-21/details.html.
8. U.S. Department of Agriculture Food Safety and Inspection Service. "FSIS Issues Public Health Alert For Specific Ground Beef In HelloFresh Meal Kits Due to Possible E. coli O157:H7 Contamination." September 10, 2022. https://www.fsis.usda.gov/recalls-alerts/fsis-issues-public-health-alert-specific-ground-beef-hellofresh-meal-kits-due.
9. U.S. Food and Drug Administration. "Company Announcement: Daily Harvest Issues Voluntary Recall of French Lentil + Leek Crumbles Due to Potential Health Risk." June 23, 2022. https://www.fda.gov/safety/recalls-market-withdrawals-safety-alerts/daily-harvest-issues-voluntary-recall-french-lentil-leek-crumbles-due-potential-health-risk.
10. Daily Harvest. "Updates on our voluntary recall of French Lentil + Leek Crumbles." July 19, 2022. https://www.daily-harvest.com/content/french-lentil-leek-crumbles-advisory#.
11. Direct to Consumer Delivery Committee. Guidance Document for Direct-to-Consumer and Third-Party Delivery Service Food Delivery. 2020. http://www.foodprotect.org/issues/packets/2020Packet/attachments/III_004_content_c.pdf.
12. Brill, J. "Study: Many Meal Kit Deliveries Contain Perishable Food Items Above the Recommended Temperature." Quality Assurance & Food Safety. February 23, 2022. https://www.qualityassurancemag.com/article/many-meal-kit-deliveries-contain-perishable-food-items-above-the-recommended-temperature/.
13. Rutgers School of Environmental and Biological Sciences, Department of Human Ecology. "Is the Food in Meal Kit Delivery Services Actually Safe to Eat?" News and Features. October 5, 2017.
14. Mickanuck, Katrina. "Investigating food safety implications of meal-kit delivery subscription services in Toronto." School of Occupational and Public Health, Toronto Metropolitan University.

Kelsey James, M.P.H., is an Environmental Health and Knowledge Translation Scientist at the National Collaborating Centre for Environmental Health (NCCEH). Kelsey has experience in occupational health risk assessment, risk communication, and knowledge translation. She holds an M.P.H. degree in Occupational and Environmental Health and a B.Sc. degree in Health Sciences, both from Simon Fraser University. She is interested in a wide range of environmental health topics, including food safety, supply chains, occupational health, and the health impacts of and adaptations to climate change. The NCCEH is one of six National Collaborating Centres created to foster linkages within the public health community. It is funded through the National Collaborating Centres for Public Health (NCCPH) program.