To effectively manage and ideally eliminate notifiable contaminants in dairy processing, it is important to focus on Good Manufacturing Practice (GMP), Good Hygiene Practice (GHP) and process control breakdowns. These three aspects of food production are the key areas within a manufacturing environment where contamination can be introduced.

Notifiable contaminants include a range of pathogens and indicator organisms. One notifiable contaminant of particular concern is listeria. Listeria monocytogenes is considered the number one food safety hazard in dairy processing.

If a lab detects a notifiable contaminant in a food sample, they are obliged to report the finding to SA Health.

Here are some key points to keep in mind when considering whether your business is set up to manage the risk of notifiable contaminants such as listeria:

  1. To control listeria, it is essential to locate it. This can be achieved through a thorough environmental monitoring program that is both systematic and reliable.
  2. Listeria is a type of bacteria that is commonly found in the environment. It can enter food processing facilities in various ways, such as on the hands, clothing, and boots of workers. To prevent contamination, dairy factories that produce soft, ripened cheeses have strict requirements for entry. However, the most critical situation for a food plant is when listeria establishes a permanent residence in equipment that comes into contact with pasteurised food. If the organism takes up residence in a hard-to-clean area, it may be impossible to prevent the recontamination of products without taking drastic measures, such as pasteurising the entire equipment or heating the processing room to over 40°C for an extended period.
  3. Since factory environments are not sterile, listeria (which is ubiquitous) can easily enter food production facilities. To prevent this, investigate and control conditions that can create niches or transmit listeria.
  4. It is essential to prevent the entry of listeria into cheese ripening and finished product areas, as it is an environmental organism that can easily enter these spaces if entrances are not well managed. Particularly strict movement controls are necessary in high-care production areas to control the potential entry of listeria.
  5. Every dairy business has a responsibility to undertake regular maintenance and repairs. This includes general wear and tear, rust, flaking paint and damage to silicone joins – all which can provide opportunities for bacteria such as listeria to harbour and grow within the environment.
  6. Regardless of premises’ size or age it is essential for every dairy processing business to implement and maintain a tailor-made maintenance program. Poorly maintained plant and equipment can contribute to product contamination by limiting the ability for effective cleaning and resulting in organic material build-up.
  7. To avoid listeria presence in the factory, it is important to pay attention to operating, maintenance, and design aspects. Kornacki Microbiology Solutions, Inc. has excellent examples of these aspects in their publication ‘Detecting Sources of Listeria monocytogenes in the Ready-To-Eat Food Processing Environment’ (2006).

Dairysafe requires immediate notification of any listeria species found in food or the environment, as well as other pathogens found in dairy products. In such cases, contact Dairysafe immediately for assistance and advice on next steps.

You can also refer to the Dairysafe pathogen management flowchart, which outlines the company’s response arrangements.

There are many resources and reference materials available to guide you in this process. Check out the Food Safety Toolbox on the Dairysafe website.