Foreign Material Control in Food Production — From Sieving to Metal Detection
August 17, 2026
One of the most important hazards in food production is the biological hazard. Bacteria, viruses, parasites, and other pathogenic microorganisms can enter food through raw materials, people, water, equipment, the production environment, or inadequate storage and processing conditions.
Among these biological hazards, Escherichia coli (E. coli) requires particular attention. E. coli normally lives in the intestines of humans and animals, but certain strains can cause serious foodborne illness. Of particular concern are Shiga toxin producing E. coli (STEC), including some strains of E. coli O157:H7, which can cause severe disease.
However, E. coli is not the only cause of foodborne illness. Salmonella, Listeria monocytogenes, Campylobacter, norovirus, and other pathogens also represent significant biological hazards for the food industry.
This is why identifying biological hazards, assessing their risks, and establishing appropriate control measures are fundamental elements of a HACCP system.
In this article, we will examine three major foodborne disease risks, where they come from, how pathogens can enter food, and how food businesses can control these hazards effectively.
1. E. coli and Other Pathogens — Where Do Biological Hazards Come From?
Pathogenic microorganisms do not simply “appear” in food. They enter the product from a specific source, and identifying that source is the first step toward effective control.
In the case of E. coli, an important source can be human or animal fecal contamination. This is particularly relevant for foods of animal origin, drinking water, fresh produce, fruits, vegetables, and other products that may become contaminated during farming, harvesting, processing, or handling.
Raw materials may already be contaminated when they arrive at the facility. If appropriate receiving controls are not implemented, pathogens can enter the production environment and potentially spread to other stages of the process.
Another important source is people.
Poor hand hygiene, inadequate handwashing after using the toilet, illness, or inappropriate hygienic behavior can result in microorganisms being transferred to food, equipment, packaging, or food contact surfaces.
A third important source is the environment and equipment.
Contaminated surfaces, drains, floors, utensils, conveyors, cleaning tools, and inadequately cleaned equipment can become vehicles for pathogen transfer.
This is why biological hazard control should never depend exclusively on laboratory testing.
The HACCP approach emphasizes prevention and control at the stage where a hazard can be effectively managed.
The objective is not simply to discover contamination after it has occurred.
The objective is to prevent contamination from occurring in the first place.
2. 3 Major Foodborne Disease Risks
Foodborne disease risks are diverse, but three major areas require particular attention in food manufacturing.
Risk 1 — Contaminated Raw Materials
If raw materials already contain pathogenic microorganisms, they can introduce the hazard directly into the production process.
For example, inadequately controlled meat may contain Salmonella, Campylobacter, or certain types of E. coli. Contaminated fresh produce can carry various pathogens, while unpasteurized milk may contain microorganisms capable of causing foodborne illness.
This is why supplier approval, raw material specifications, receiving controls, supplier performance monitoring, and, where appropriate, laboratory testing are important elements of food safety management.
The level of control should be based on risk.
High-risk raw materials require stronger preventive measures and closer monitoring than materials with a lower likelihood of introducing biological hazards.
Risk 2 — Cross-Contamination
Cross-contamination occurs when a pathogen is transferred from one source to another product, surface, piece of equipment, or person.
For example, if raw poultry is processed and the same equipment or utensils are subsequently used in a ready-to-eat area without effective cleaning and disinfection, pathogens can be transferred to food that will not receive another kill step.
Cross-contamination can also occur through employees’ hands, gloves, protective clothing, containers, transportation equipment, or cleaning tools.
This is particularly important in facilities where raw and ready-to-eat products are processed in the same environment or where production zones are not properly separated.
Effective zoning, hygienic practices, equipment segregation, cleaning and sanitation, and controlled personnel movement are therefore essential.
Risk 3 — Inadequate Time and Temperature Control
Many pathogenic microorganisms can multiply rapidly when conditions are favorable.
If perishable food is stored or transported for too long at inappropriate temperatures, microbial growth can increase and the risk of foodborne illness can become significantly higher.
Time and temperature control is therefore particularly important for meat, dairy products, ready-to-eat foods, seafood, cooked foods, and other perishable products.
In some processes, thermal treatment is a critical control measure that reduces pathogens to an acceptable level.
However, controlling the kill step alone is not enough.
After heat treatment, the product must also be protected from recontamination.
This is why HACCP requires attention not only to the pathogen reduction step, but also to all subsequent processes that could introduce contamination again.
3. How Can E. coli and Other Biological Hazards Be Controlled?
Effective biological hazard control begins with a risk-based approach.
Within HACCP, a food business must identify where biological hazards may occur, determine their possible sources, assess their significance, and establish appropriate control measures.
The first important layer is GMP and GHP.
Effective handwashing, protective clothing, hygienic behavior, controlled movement between production zones, segregation of raw and ready-to-eat products, and appropriate handling practices form the foundation of daily prevention.
The second layer is cleaning and sanitation.
A food facility should have an effective Cleaning & Sanitation program defining what needs to be cleaned, how it is cleaned, how frequently cleaning takes place, which chemicals are used, and how effectiveness is verified.
Particular attention should be paid to drains, difficult-to-clean areas, equipment niches, and other locations where microorganisms may survive and potentially spread.
The third layer is thermal processing.
When product safety depends on cooking, pasteurization, or another heat treatment, the relevant process parameters must be properly established and controlled.
Temperature, time, and other critical parameters should be monitored, recorded, and verified where necessary.
The fourth layer is water and raw material control.
Water that comes into direct or indirect contact with food must meet applicable requirements. Suppliers should be evaluated according to risk, and appropriate specifications, certificates, analytical results, or other supporting documentation should be available where necessary.
The fifth layer is environmental monitoring and laboratory control.
Microbiological testing cannot replace HACCP or preventive controls. However, it can provide valuable information about the effectiveness of sanitation and environmental controls.
Trend analysis is particularly important.
One isolated result may require investigation, but repeated findings or increasing trends can indicate a deeper process or sanitation problem that requires root cause analysis.
4. HACCP — Turning Biological Hazards into Manageable Risks
The strength of HACCP lies in its ability to help food businesses control biological hazards before they become a problem for consumers.
During hazard analysis, each production step should be evaluated to determine whether pathogens such as E. coli, Salmonella, Listeria, or other microorganisms could be introduced, survive, or multiply.
Appropriate control measures can then be established.
Depending on the process, these may include raw material controls, thermal processing, time and temperature management, pH, water activity, sanitation, hygienic zoning, or other preventive measures.
When a step is identified as a Critical Control Point (CCP), the business must establish a clear critical limit, monitoring procedure, corrective action, and verification process.
However, HACCP does not consist only of CCPs.
Effective biological hazard control also depends on strong Prerequisite Programs (PRPs), including GMP, GHP, Cleaning & Sanitation, Pest Control, personnel hygiene, water quality management, supplier control, traceability, and other relevant programs.
Together, these controls create multiple layers of protection.
If one control fails, another control should reduce the likelihood that the hazard reaches the consumer.
This is why an effective HACCP system is not simply a document.
It is a daily management system involving monitoring, records, verification, corrective action, employee behavior, and continuous improvement.
Conclusion
E. coli and other pathogenic microorganisms are significant biological hazards that can cause foodborne illness.
The main sources of risk can include contaminated raw materials, people, water, equipment, the production environment, cross-contamination, and inadequate time and temperature control.
Food businesses should not wait until a problem is detected in finished product.
Biological hazards must be identified before production begins, and appropriate preventive controls must be integrated into everyday operations.
HACCP, GMP, GHP, effective Cleaning & Sanitation, personnel hygiene, raw material controls, thermal processing, environmental monitoring, and verification work together to create a strong system for managing biological hazards.
Food safety does not begin in the laboratory after contamination has been detected.
It begins much earlier, when a business identifies how contamination could occur and establishes controls to prevent it.
Controlling biological hazards means more than detecting pathogens. It means preventing their introduction, survival, and growth throughout the food production process.
