Manufacturing site design, equipment, processes, and product range impact on the presence, risk and control of allergens. This section provides information about reviewing allergen risks during production.

  1. Gather a cross-functional team
    Personnel who have an in-depth knowledge of the processing equipment and manufacturing procedures are ideal for identifying where allergen cross contact can occur due to processing. The team could consist of production staff, engineers, quality specialists and schedulers.
  2. Map out the process
    As each manufacturing site is different, create a map of the facility that identifies the flow of raw materials, processing, products and people. The map can be used to: –
    • Identify where allergens are present on site
    • Set in place processes that control how allergens are transferred within the facility
    • Inform staff of the flow of allergens
  3. Perform a physical audit at the most appropriate time
    Where possible, a physical audit of the processing area and equipment should be completed. Consider any procedures in place to prevent allergen cross contact. For example, if factory procedures state that a clean will take place between products which have different allergens, then ensure that the audit takes place during the clean to assess its effectiveness. This allows allergen risks to be identified in situ by the cross-functional team and ensures a shared perspective of allergen risks.
  4. Identifying cross contact points
    Equipment such as ladders, torches and drain cameras may be required when looking for cross contact. Most residue points that are easily seen and accessible should be included in the cleaning procedure. Areas that are not commonly accessed may need to be investigated to find opportunities for cross contact. It may be necessary for engineers to pull apart equipment to identify cross contact points.
  5. What is the form of the cross contact?
    Consider the form or the nature of the cross contact material as this will influence the allergen behaviour and risk. Cross contact that cannot be eliminated needs to be categorised as a particulate or a readily dispersible form. Consider the form of the allergen in the product and how it will be distributed through the next product.
  6. How much cross contact is present?
    Once potential for cross contact has been identified, and it cannot be eliminated or reduced, it must be quantified. It may be necessary to collect (weigh, measure, calculate, vacuum, sweep, swap) the residue to quantify it. Engineers may be able to assist if quantities are to be estimated. The maximum quantity of product which can become incorporated into another product should be determined for each cross contact point.

Understanding the quantity of cross contact occurring due to processing is essential for undertaking an allergen management plan and can be used for a VITAL risk assessment. For the VITAL Program, understanding the amount of Hang Up from points such as pipework; equipment such as pumps, mixers, homogenisers; conveyors; airborne dust and; utensils, are all useful.

The following information is required before a VITAL risk assessment of the cross contact due to processing can be conducted.

The processing profile – In the VITAL Program, the processing profile represents a manufacturing process or it may represent part of a processing sequence, or even a piece of equipment. An example is the process from ingredient preparation through to packing.

Nature of the allergen – is the allergen in particulate or readily dispersible form?

Quantity of Hang Up – the maximum amount of Hang Up should be identified in terms of weight (grams). If the product is in liquid form, use appropriate factors such as specific gravity or apparent density to convert the Hang Up into grams.

The percentage of the allergen component within the Hang Up – this figure reflects the composition of the Hang Up. For example, if the Hang Up is composed of the previously run product, then the ‘percentage of the allergen component within the Hang Up’ will be the percentage of the allergen component(s). If the previously run product contains 15% milk then the percentage of milk allergen component within the Hang Up would be 15%.

The percentage of protein within the allergen component of the Hang Up –  can be determined using product specifications (e.g. PIFs), food composition tables and/or other relevant literature. Following on from the example above, if the relevant allergen is milk , then the percentage of protein in milk can be determined from the specification for this product (in the nutrition section under g per 100g of protein) or other relevant source.

Batch size exposed to the Hang Up – this is the weight (kilograms) of product into which the Hang Up will become homogenously distributed. Examples: batch size, filler bowl size.

Some production processes may be made up of a relatively simple batching process, others may be more complex continuous processes. Some batch sizes may vary, and some processes may start with a batching process and finish as a continuous process. The batch size exposed to Hang Up represents the amount of product within a batch into which the hang up will become homogenously incorporated. That is, it may not be the batch size that is allocated for manufacturing purposes. Careful consideration is required to determine the appropriate batch size exposed to the Hang Up.
The batch size should represent the maximum possible concentration of cross contact allergen. For example:

  • in some cases, a product can be made up using different batch sizes (say, based on customer demand), the smallest possible batch size should be used
  • a 30-ton continuous process is sent to a filler with 200kg capacity. The cross contact occurs homogenously in the first 200kg after which there is no residue. In this case the 200kg is the batch size

In most cases the batch size is the smallest amount into which the cross contact allergen is homogenously distributed. This results in the greatest concentration and the most conservative figure for a VITAL risk assessment.

This link provides an example showing how to calculate the quantity of readily dispersible cross contact in a processing profile. Case Study – Hang Up

Process design

As part of the risk review, map out the manufacturing facility and identify where raw materials and finished products that contain allergens are located and where the allergens are introduced during processing. Map out the travel paths of all people (and vehicles such as forklifts etc.) including all entry and exit points, and product throughout the site (including finished product and dispatch). This information defines how allergens are currently handled and can be used to make changes to improve allergen controls.

Equipment design

The way manufacturing equipment is designed can have a significant impact on the creation or reduction of cross contact. Equipment that has no Hang Up points, is easily cleaned and easy to inspect is ideal for allergen control. If equipment does have Hang Up points, or is not easily cleaned, extra steps (such as scheduling programs, cleaning programs) will need to be in place to manage cross contact.

  • Can dedicated areas be allocated for handling ingredients that contain or do not contain allergens?
  • Does the facility have sufficient ventilation / sufficient extraction? Can airflow be adjusted to prevent airborne cross contact? Some equipment may recycle compressed air. Consider whether this poses an allergen risk?
  • Inspect the layout on the production line. Can physical barriers be put in place to prevent cross contact (such as where lines crossover)?
  • Can personal protective equipment be used as means to identify allergen presence during production, such as using different coloured uniforms or hair nets. Can personnel movement be restricted where possible or if required?
  • Install intermediate storage controls (for example, dedicated small storage areas for each production line or product type)
  • Are processing lines located close to each other? Can separation be controlled by production scheduling and cleaning validation? Is there enough room to clean effectively?
  • Can utensils be colour coded / cleaned and inspected before and after being used for allergen containing products?
  • Are procedures in place to prevent the wrong line set up by mistake, or the wrong piece of equipment (e.g. pump) or running product partially through the wrong line (such as through complex pipework). If it does occur, are there ways to identify and manage this?
  • Is it possible to have dedicated lines, areas, and equipment, or even a site dedicated to particular products?
  • Can the line be re-engineered, or pipework reconfigured to remove Hang Up points?
  • When purchasing new equipment, consider how allergens will be controlled and how easy the equipment will be to clean. Can the equipment be dismantled, how easy it is to do, and how long does it take?
  • When installing equipment, consider how allergens will be controlled. Include the HACCP team at concept stage. Consider the impact of CIP (Clean in Place) systems. Will the new equipment be connected to existing systems and what are the implications?
  • Some lubricants contain allergens, check the technical data sheets confirm the allergen status. Implement controls to manage this.
  • Can equipment be designed and laid out in a manner to prevent cross contact? Alternatively, does the connection of the new equipment create a new Hang Up point?