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From: Food Quality & Safety magazine, April/May 2008

Freedom From Allergen Risk

How to ensure the integrity of allergen-free supplies

by Simon Flanagan

A quick review of product recalls and withdrawals in any given week reveals that allergens, and the need to declare their presence in foods, represent a massive challenge for the global food industry. In one week’s recalls in the United States, for example, inaccurate labeling resulted in the recall of sandwich rolls (undeclared milk), ice cream (undeclared almonds), salmon spread (undeclared egg), and ice bars (undeclared milk). No category of processed and packaged food is invulnerable to the risk of mislabeling, and no food product is immune from the possibility of giving an incomplete description of ingredients.

If the risk is great for the average food company, then it is arguably greater still for those manufacturers in the “free-from” sector. For these companies, it is never merely a question of complying with labeling legislation. Rather, consumers are relying on the accuracy of any free-from statements to protect their health and ensure they are buying food suitable for their needs. The consequence of mistakes is potentially very serious, both to consumer health and to the reputation of the manufacturer.

It is especially important that free-from producers properly understand the ingredients they use and the way those ingredients have been processed to justify any free-from claims they might wish to make.

The legal responsibility for accurate labeling rests ultimately with the manufacturer, but the practical responsibility extends throughout the supply chain. Whether the manufacturer is in the free-from sector or not, suppliers will be favored if they are willing and able to show they have the necessary controls in place to manage allergen risk in their factories. Ingredient suppliers that are willing to work with manufacturers and share information will be best placed to secure long-term contracts.

As the best documented and most potent of all allergens, nuts can be used to illustrate many of the issues that must be addressed when producing a free-from product. This discussion starts with definitions. Peanuts, for example, are not nuts at all. They are legumes, more closely related to peas and soya. Few of us would argue, however, that a nut-free product might legitimately contain peanuts; it matters both how statements like “nut-free” are used and how they are understood by consumers. Similar potential difficulties arise in defining eggs, crustacea, milk, and other allergens that may be used.

This is not merely a question of semantics. It is absolutely fundamental that ingredient suppliers and their customers fully understand what is being supplied and know what other ingredients have come into contact with those supplies as a consequence of either storage or processing. It is equally dangerous to assume that consumers will recognize that a certain type of product will always contain a certain ingredient (e.g., milk as an ingredient in parmesan cheese). When it comes to allergens, assumptions, misunderstandings, and the absence of even a small piece of information are likely to lead to problems.

An Allergen-Free Strategy

To avoid the unintentional presence of any allergen in a product, evaluate all routes of likely inclusion, both deliberate and accidental. This is most effectively accomplished using hazard analysis and critical control point (HACCP) principles, with which most manufacturers should be familiar. All critical control points must be documented—and controls put in place—to prevent contamination, with internal auditing used to ensure their efficacy.

Most food and ingredient producers already employ good manufacturing practice (GMP) to ensure safe food production. GMP requires appropriate manufacturing operations, effective food safety systems linked to HACCP-based principles, and quality assurance systems, as well as commitment and discipline to ensure that products meet food safety, quality, and legal requirements. With respect to “allergen-free” manufacture, the following factors need to be considered:

  • training and communication;
  • raw materials and supply chain;
  • monitoring and review;
  • plant sanitation;
  • manufacturing premises, equipment, and processes; and
  • labeling.

All of the above areas need to be covered by detailed standard operating procedures (SOPs) in order to guarantee uniformity in practice.

Training and Communication

Education is key to allergen control, and all employees must be fully committed to the policy and aware of the implications of failings. Training sessions should be tailored to meet the specific operational sectors of the organization and should include temporary staff and contractors. For example, those involved in handling ingredients, equipment, utensils, packaging, and products should be trained in:

  • potential allergen cross-contamination situations;
  • hand washing;
  • clothing requirements;
  • re-work;
  • waste control;
  • cleaning procedures;
  • dedicated equipment use; and
  • general good housekeeping.

Training messages should be backed up with clear signage so that all employees and visitors are aware of the site’s allergen control policies. Refresher training should be completed at set intervals.

In addition to these basic training requirements, instruction should ensure that employees working in areas where color-coded systems are used to segregate equipment are able to identify color differences (e.g., training should include checks for color blindness).

Raw Materials and Supply Chain

The stringent policies adopted to exclude allergens need to extend to the entire supply chain. For a food manufacturer switching from non-dedicated to dedicated free-from production, this usually requires some fairly exhaustive preliminary work. Ingredient suppliers should expect their own practices to be thoroughly scrutinized by their customers and should carry out extensive checks on their own suppliers and distributors.

Manufacturers should demand that their ingredient suppliers complete an extensive allergen questionnaire to qualify the risk of contamination in their ingredients or facilities. Those candidates identified as able to supply allergen-free ingredients should then be subject to a third-party audit, using the questionnaire as the basis for the audit standard.

Ingredient suppliers should make similar audits of their own suppliers; once the supply base is established, the allergen-free policy can be reinforced using binding contracts, which should extend to the purchase order system.

Analytical Testing of Ingredients

Before manufacture, an initial comprehensive ingredient screening regime is needed to validate the findings from the supplier risk questionnaire/audit. Testing will form the basis of this screening, and the frequency of sampling will be dictated by the inherent risk of contamination associated with a given ingredient. The actual route of likely contamination will also need to be taken into consideration when devising specific sampling plans: for example, nut fragments (hot spots) versus residual surface cross contact (homogeneous).

An independent, accredited laboratory using the most sensitive, validated methods available should conduct the testing. It is worth remembering that no test can show the absence of an allergen; it can only prove that a given allergen is not present at levels that exceed the limit of detection. So, although a negative result cannot be taken as a 100% guarantee that an allergen-free ingredient has been produced, a positive result definitely reveals that allergen-free production has not been achieved.

It is also worth remembering that any analytical technique needs to be fully validated for use on a particular food matrix. For example, there are many commercially available assays for nut allergens, but it is preferable that contract labs use enzyme-linked immunosorbent assay kits approved by internationally recognized organizations such as AOAC. The lab itself should also have external accreditation (e.g., International Organization for Standardization or the United Kingdom Accreditation Service).

The results from the initial screen can be used to construct a matrix based on analytical results and audit findings. Only suppliers that meet both prerequisites should be sanctioned for use in allergen-free manufacture, and this level of screening must be maintained until the manufacturer has complete confidence in the allergen-free status of ingredients. This screening process should also be mandatory for all new production batches. Once the manufacturer is confident about the ingredient, the sampling frequency can be reviewed accordingly.

The detection of a positive result above the action limit—a quantifiable result—should automatically trigger the rejection of an ingredient and the reinstatement of the supplier/ingredient to the original sampling frequency. This situation should persist until it can be reliably demonstrated that the contamination issue has been resolved. Of course, the ingredient supplier needs to have an effective traceability system in place so that any recalls that are necessary can be carried out effectively. This system can be tested, as can the decision-making process leading up to a recall.

Reading Scientific Services Ltd. (RSSL; Reading, U.K.) recently ran an incident management scenario for members of its emergency response service in which participants were progressively introduced to a scenario of escalating crisis built around contamination of product with peanut protein. The event successfully challenged participants to work out just when and how the decision to recall might be reached. Any training of this kind is useful in helping a business deal calmly with a potential crisis.


Plant sanitation matters most where equipment is used both for allergen-free production and standard production. Of course, it is preferable to have dedicated or strictly segregated production, and, in this instance, intensive allergen sanitation is a prerequisite following plant or zone dedication. In theory, the only other case in which intensive allergen sanitation would be required would follow the detection of a contaminant.

In any event, all cleaning processes need to be validated using environmental monitoring tools such as process swabs coupled with rapid diagnostic techniques. It is not safe to assume that a given cleaning method is equally suited to removing all kinds of contamination from all kinds of surfaces. RSSL recently conducted a survey on behalf of the Anaphylaxis Campaign (as yet unpublished), which reveals some inconsistencies around cleaning procedures, so it is important to validate cleaning techniques to be sure they are doing the job as intended.

Premises, Equipment, and Processes

By definition, dedicated manufacture seeks to completely exclude the physical presence of the specified allergen from the site. Where dedication is not possible, the only sensible approach is to create an allergen-free production zone by installing a physical barrier.

Within the allergen-free zone, all processing equipment should be dedicated and completely sealed to prevent airborne particulate contamination from entering other manufacturing zones. Separate air-pressure and air-conditioning systems are also essential.

Color-coding of all processing equipment and clothing will help to highlight their respective dedication. Best practices will also ensure that each zone has its own changing room, development kitchen, quality assurance lab, engineers’ tools and workshop, tray wash machinery, canteen, first aid room, and even office equipment. This dedication should extend into the warehouse, where all raw materials should be segregated through separate intake and storage areas. Clear signage can be used extensively to reinforce training messages about the importance of segregation.


The labeling requirements mentioned at the start of this article are not applicable to ingredient suppliers, but the overriding obligation that applies to all parties in the supply chain is to provide accurate information to customers. Whether the customer is the end consumer or a food manufacturer, the goods being traded must be described accurately and completely. This description may even provide details of how the ingredients have been transported and packaged, because both of these have been identified as actual sources of cross contamination and will always be potential sources.

Clearly, the supply of allergen-free ingredients and the production of free-from foods are not beyond the scope of the food industry, although the process is never straightforward. All partners in the supply chain have their part to play in ensuring the integrity of allergen-free supplies. There are potential benefits for all concerned when this cooperation can be established and maintained. With reports suggesting that an increasing number of consumers exhibit allergic responses, the market for allergen-free foods and allergen-free ingredients looks set for potential growth.

Flanagan is the head of specialty analysis and allergen services, Reading Scientific Services Ltd. For more information, email or call +44 (0) 118 986 8541.



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