How to Address the Risks of Cross-Contamination at Your Food Testing Lab


Microbiological cross-contamination is one of the most common causes of foodborne illnesses. The presence of pathogenic bacteria, chemicals, heavy metals, allergens, and foreign objects in food products can pose a major risk to consumers’ health and wellbeing. Cross-contamination can occur at any point in food production. Identifying food contamination is essential before supplying food products to consumers. Food safety necessitates the implementation of preventive measures and food quality testing against predetermined quality standards. Establishing standardized processes that assure food safety and quality makes it easier for manufacturers to comply with the regulatory standards, guaranteeing that the food is safe for public consumption.

Causes of Cross-Contamination in Food Samples

1. Poor Environmental Conditions

It is essential to maintain a clean environment for sample collection, storage, and analysis. An unsealed sample can come in direct contact with airborne contaminants. Environmental factors, such as humidity levels, temperature, or exposure to light, may affect the sample quality. Contaminants in air, ovens, furnaces, or refrigerators can also deteriorate a sample and adversely affect the accuracy and validity of test results.

2. Uncleaned Tools and Equipment

A sample needs to be stored in a chemically inert and gas-tight container to prevent cross-contamination and keep the oxygen level low in the container, thereby increasing the shelf life of the sample. Moreover, samples can get contaminated from unclean sampling tools. Sampling tools should be well sterilized and should be maintained separately for different types of samples. It is also essential to use clean glassware while performing the analysis.

Cross-contamination can also occur from broken containers, the proximity of other samples, and dirty benches or weighing machines. Tools, such as spatulas and other sampling tools, must also be cleaned thoroughly.

3. Impure Reagents

Few reagents fall below the specified purity grade and contain impurities. It is therefore important to obtain reagents from reliable sources otherwise it could lead to errors.

4. Hygiene Levels of Laboratory Personnel

An analyst can majorly contribute to contamination in food samples. Laboratory personnel should strictly use disposable gloves, head covers, face masks, and clean laboratory aprons. The staff of microbiological testing laboratories should maintain good levels of hygiene along with personal cleanliness. Laboratory staff should undergo comprehensive training on best practices for sample handling to avoid cross-contamination.

5. Laboratory Visitors

Clothes and footwear of visitors are also potential sources of contamination. In case of an emergency visit, visitors should be provided with protective clothing and laboratory footwear like any other laboratory worker.

Preventive Measures to Control Cross-Contamination in Food Testing Laboratories

1. Automate Laboratory Processes

The best way to avoid contamination in laboratory samples is by automating laboratory processes wherever feasible. Automation can significantly reduce the risk of human errors and can prevent cross-contamination of samples.

2. Use Sterilized Tools & Equipment

It is crucial to maintain a sterile work environment in a food testing laboratory. The tools and equipment should be cleaned regularly before analysis. It becomes difficult for large-scale laboratories to clean and sterilize all equipment regularly. Automated equipment, such as a lab water purification system, can be used to effectively sterilize various equipment in less time. Autoclaving is another method that involves applying intense heat and pressure for cleaning laboratory tools and equipment. A solution of ethanol is also used to remove all bacterial and fungal contaminants. It is essential to clean and sterilize the glassware thoroughly to reduce the risk of contamination.

3. Maintain a Clean Laboratory Environment

It is important to check the quality of air and water in a food testing laboratory. It is essential to maintain an environment that is clean and hygienic while performing operational activities. Testing for allergens and chemical contaminants in the air and maintaining sanitary and hygienic conditions at every stage is important to reduce cross-contamination.

4. Maintain Well Packaging of Food Products

Antimicrobial surface coatings and plastic alternatives are used for packaging food products. Such practices aid in making food and beverage products safer for consumers.

How Can a LIMS Help?

It is important to perform analytical testing of food and beverages to ensure food safety and assure the quality of food products. A laboratory information management system (LIMS) helps automate workflows to minimize manual errors and turnaround time and maximize efficiency.

Laboratory software for the food and beverage industry, also known as Food LIMS, can be integrated with laboratory monitoring systems to monitor the laboratory environment and raise an alarm if there are any deviations from optimal conditions. A LIMS can also be integrated with risk analysis tools to determine the risks of cross-contamination at various points, especially critical control points, in a food testing facility. A LIMS can be used to compare the results of quality control samples with the food samples to be tested, enabling laboratories to identify cross-contamination. A LIMS also helps in maintaining records of corrective and preventive actions taken if cross-contamination is detected. Most importantly, laboratory software for the food and beverage industry enables testing laboratories to meet regulatory guidelines and standards such as ISO/IEC 17025:2017, HACCP, and state and local regulations.


Cross-contamination in food samples can occur in various instances in a laboratory setting. However, the measures discussed above can significantly reduce the risk and avoid contamination in food samples. The best way to avoid cross-contamination is to automate laboratory workflows, streamline QA/QC processes, and exercise strong process controls which can be achieved by deploying a LIMS. Furthermore, laboratory software for the food and beverage industry helps meet necessary regulatory requirements and assure the quality and reliability of the final product.