Are you controlling allergen hazard for returnable packaging?

By Guest Author on 20 June 2019

There is a new buzz among food packaging manufacturers: How to manage allergen(s) when shipping materials are sent back from manufacturers who facilitate declared allergens. Third party auditors are noticing return program of dunnage and are asking questions.

Let us share with you a true story. As a plastic bottle manufacturer, controlling allergens was as easy as requiring employees to wash hands after eating. Then one day, incoming inspection of returned empty boxes from a food manufacturer were coated with mustard smears. Suddenly, cross contamination of allergen was on our receiving dock! Now what do we do? And how do we manage those allergens?

Dunnage, corrugated cartons, trays, pallets and other shipping items are often sent back to the packaging manufacturer for reuse. This return program is viewed as cost saving and good for the environment. It is estimated that return packaging may grow from <5% to approximately 20% in the near future.

Influencing factors such as negative environmental impact issues are not expected to diminish significantly anytime soon and several governments are developing politics to promote global circular economy; it is expected an increasing number of potential situations where materials are reused and allergen cross contamination may occur (as was not predicted in the past).


Before packaging manufacturers accept returnable packaging, it must be considered if this practice can introduce allergens into their facilities. For that, the best option is to require clients to provide declared allergen list with steps to control said allergens followed by visiting client’s facilities, understand their processes and look closely at the flow patterns of the packaging that will be returned. This means that not only the packing itself (after being used) and the place of storage should be monitored but also where the packaging flows inside the client’s facilities and which food products it maybe in contact with. The first step is to work closely with the client to prevent or minimize contamination of the returnable packaging with allergens. For that, it should be considered to examine client’s risk assessment on allergens and/or even the packaging manufacture
should perform its own allergen risk assessment at the client’s site.

Another important aspect: Is the packaging is washable? Can the clients cleanse the packaging with efficient processes? Checking these issues should be another point to include on the checklist when visiting the client. Certainly, when reusable plastic pallets are returned, this program should definitely be considered an option to eliminate the risk of returnable packaging carrying allergens back to manufacturer facilities.

In the case of unavoidable contamination by allergens, procedures must be putin place to validate if cleaning procedures (when applicable) are efficient in removing allergens or to verify if other control measures are achieving the intended results. For that the use of swab tests to detect the presence of allergens are a great option to consider.

Before we go in more detail, we would like to present a diagram that can be of guidance regarding how to manage this issue.

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Figure 1 - Managing allergens in returnable packaging

Requiring a letter to guarantee that the packaging returned is free from allergens is the simplest of all. Despite that, the core essence of a food safety professional is to guarantee people can eat food products without getting sick and not guarantee that if that happens the responsibility can be addressed to another stakeholder. So, in case of doubt or any lack of confidence, the better option is for the packaging manufacturer to take charge of the responsibility of controlling the hazard. That being said, letters of guarantee may still be used and retained as important records of any food safety system.

Another option is to settle an agreement that the client should control the presence of allergens either by washing and monitoring efficiency and/or by controlling allergens prior to returning to manufacture facilities.

The last option presented is the one that requires more effort from the packaging manufacture’s side since the cleaning and/or control of allergens is their responsibility. In fact, even when a packaging manufacture opts by one of the other options, especially if only for the letter of guarantee, it will be recommended that some verification is done internally, such as swab test.

Choosing between one of these options or even use them all would be something that the packaging manufacturer should consider according to risk assessment conducted on the client’s site. In the next section different solutions are presented for different scenarios (each food safety professional should look to the particular circumstances of its organisations and clients and decide the best options, the solution provided are
only hypothetical).

Addressing this issue will no doubt require some time and money investment. The overall cost will depend if the preventive control is made more on the client side than the manufacture and if the services of an outside lab are required. There are in the market swabs designed to screen the presence of allergens that can be a great tool for procedures control and validation.

So that you can see that the different options can be used alone or in combination according with circumstances we settle different scenarios and share what can be done in each of them.

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  1.  New Client
    In this scenario where no historic performance information from the client is available the preferable option is that the manufacture controls the presence of allergens. Consequently, when a Supply Agreement is settled, one of the clauses should assign the responsible party. Even when it is settled that the client is responsible, at least on the first 2 to 3 purchases the packaging manufacturer should verify by swab test incoming returnable packaging for allergens. It is strongly suggested that a visit is conducted at the client’s facilities to verify their allergen management practices and programs prior to reducing or eliminating the internal control.
  2. Long-time client
    If the client works with the packaging manufacture for long period of time, wheretrust was built on history of no contamination to returned packaging and continued verification activities at their facilities, this may be the perfect scenario where the use of (only) a letter of guarantee is viable. Even in this scenario, it may be considered the clients routinely sharing current records associated with allergen management/control
  3.  GFSI certified client
    If you have a client (new or long-time) that is GFSI certified it may be reconsidered the necessity of a visit/audit of the client. In this case, having a letter of guarantee and information when they have some issue related with allergen control (e.g. via review of audit records) may be enough to manage allergens presence in returnable packaging. Nevertheless, these organisations may be included in a routine check with periodicity depending on historical performance.
  4. Non-food client
    It is worth mentioning that food packaging manufacturers frequently are diversified selling to food and non-food clients. Can you hear the questions a third-party auditor would ask about a non-food client? Have you been to the client’s facility? Does your client have a pest control program? Does your client have harmful chemicals that could cross-contaminate your plant? Have you completed a risk assessment? Ultimately, you must take into consideration the hazards which can be introduced by nonfood client return dunnage and likely implement controls that are no different from the ones implemented for food clients.


The issue of allergen control enforcement on returnable packaging is probably still under the radar of many food safety professionals. But that’s about to change! This problem is being increasingly raised during 3rd party audits and is better that organisations have systems in place to prevent this industry’s process allergen contamination before any auditor asks for it, right?

There is no definitive solution that can be used in all situations. Food safety professionals must make decisions based on risk assessment, verification activities, and their knowledge and trust of the client's ability to provide truthful information and efficient control. Food safety is by principle preventive, so before we start jumping into extra costs by acquiring swabs or sending samples to the lab, be sure to join efforts with
clients in doing all that is possible to prevent allergens reaching your facilities in the first place.

About The Author:

Nuno F. Soares was born in Oporto (Portugal).
Who knows him well often complains about his obstinacy about achieving what he wants. That is maybe the reason why today he is not a Judge as his mother so wished. At the time (1993), his interest for science (particularly Biology) and engineering took him in another path. As he put at the time “I wish to do something in those fields that has an impact in people’s lives”. Nuno F. Soares has been doing just that since 1999 contributing to the consumption of safer food products.

About the Co-Author:

Jeannette works in Quality Management for over 15 years in the food packaging industry. She lead 6 North American manufacturing sites to successful FSSC 22000 certification as well as ISO 9001:2015. She is certified FSSC22000 & ISO9000 lead auditor.

She enjoys traveling near water hunting for seashells and fishing. She loves singing with her church choir, volunteering feeding homeless and spending time with family.

You can reach the authors at:

The information contained on this article is based on research done in the last months and the authors personal experience and opinion. It is not intended to represent the view of any organization they work for or collaborate with. The author will not be held liable for the use or misuse of the information provided in the article.