Cross-Contact vs. Cross-Contamination

Prior to developing the rules of the Food Safety Modernization Act (FSMA), FDA considered the term “cross-contact” to be synonymous with “cross-contamination.” Then in the 2013 FAQ publication on the proposed Preventive Controls rule, the agency began differentiating the terms.

Stating that it was following the shift in scientific literature, FDA defined “cross-contact” to mean the unintentional incorporation of a food allergen into a food, with cross-contamination having the more general meaning of contamination from insanitary objects; from personnel to food, food packaging material, and other food-contact surfaces; and from raw product to processed product.

With this distinction, is there a difference in sanitation controls that food-processing facilities should implement for the two?

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In the final Preventive Controls rule, FDA continues to distinguish the two but tends to reserve the term cross-contamination for that between raw and cooked products, while otherwise using the more general term, contamination. However, with no guidance yet published on the sanitation controls of the Preventive Controls rule, FDA’s 2013 Q&A document on the rule, as proposed, provides a look at the agency’s thinking at the time.

In that document, FDA cites examples of sanitation controls to prevent cross-contact as including procedures for:

• Ensuring that production utensils and maintenance tools do not transfer an allergen from one product to another (e.g., by proper cleaning of utensils and maintenance tools between uses if it is not practical to dedicate utensils and tools to specific processing lines).
• Ensuring that personnel practices do not result in transfer of allergens from one production line to another (e.g., by ensuring employees do not handle food containing an allergen and food that does not, without washing hands and changing outer garments).
• Minimizing the transfer of dust that could contain allergens (e.g., by cleaning powder spills around dumping stations as they occur).

To prevent cross-contamination, FDA cites examples as being procedures for:

• Ensuring that personnel do not touch insanitary objects (e.g., waste, trash cans, the floor, and restroom fixtures or surfaces) and then food, food-contact surfaces, or food-packaging material without first washing and sanitizing their hands.
• Protecting food packaging material from environmental contamination.
• Protecting exposed food products from contamination from the environment.
Controlling traffic (including that of people and equipment) between the raw and finished sides of the operation.

SANITATION RECOMMENDATIONS. But regardless of the focus, the FSMA rules necessitate stricter sanitation controls to minimize or prevent incidents of direct contamination, cross-contact, and cross-contamination. So facilities need to consider aspects of site design, equipment construction materials, utensils and tools, and personnel hygiene practices among other food safety system requirements, said Remco Products Corp. Education and Technical Support Manager Amit Kheradia. In Table 1, Kheradia provides recommendations for managing incidents of each of the three types of contaminations through color-coding.

While understanding the differences between contamination and contact, it also is important to recognize the areas in which sanitation controls can apply to both to help facilities exceed FSMA requirements.

Some relevant practices that should be applied in food and beverage processing facilities include:

1. Do not mistake sanitizing to be a substitute for cleaning. The cleaning process (wet or dry) removes debris, dirt, dust, grease, and grime, and washes away germs, but does not kill micro-organisms. Sanitizing a surface – through an EPA-approved chemical, or heat, steam, or other appropriate method – kills most micro-organisms (i.e., exhibiting at least a five-log kill where 99.999% of the germs are eradicated). However, even if you will be sanitizing a surface, you should clean it first since a layer of dirt, dust, or grime can reduce the efficacy of chemical sanitizers, Kheradia explained.
2. Do not confuse sanitary zones with hygienic zones. Sanitary zones are environmental monitoring zones for detection of pathogens of public health significance, as based on the level of food safety risk to the food being produced. For example, food-contact surfaces and environmental controls are more critical in Zones 1 and 2 than in Zones 3 and 4, which are farther from the focal production zone, Kheradia said. But hygienic zones are based on the expected level of hygienic practices required at each area, he said. For example, production zones where product is exposed require that employees wear hairnets, wash their hands, and wear gloves if touching food. So, the level of GMPs here is higher than at the finished goods storage area, where the final product is stored and employees are generally not required to wear gloves, etc.
3. Carefully plan in-production sanitation. The increased FSMA focus on allergen controls increases the need for sanitation during the production day to guard against cross-contact between allergenic and non-allergenic product runs. However, this means that plants need to carefully consider the scheduling of these clean breaks, said Clean-Logix Business Development Manager Donald Jones. Consider how you may need to isolate a line to prevent spraying of other producing lines, how to clean dividers or plastic walls (e.g., in a seafood plant) which could result in airborne spray, etc. “A lot more planning has to go into these cleaning crews,” he said.
4. Use hygienically designed implements. “It is interesting to find that very few cleaning tools are developed with good hygienic design in mind,” Kheradia said, citing an independent research study that noted that though Listeria monocytogenes was rarely present on food processing equipment, 47% of the cleaning equipment sampled was positive for the pathogen. Hygienically designed tools are normally free of crevices and contamination traps, have a smooth finish, are made of food-safe materials, and are non-porous and durable in terms of chemical and temperature resistance, he explained. Thus, they are easier to clean, minimizing the risk of product contamination by micro-organisms, allergens, and other foreign bodies.
5. Color-code equipment, utensils, and protective clothing. “Color-coding enhances separation of functions within a food processing facility,” Kheradia said. For instance, if red handling tools are allocated for raw material, green for allergens, and blue for non-allergenic processing, it is easier to use and manage these in the right areas, and this level of traceability may go a long way toward preventing costly recalls due to cross-contamination.

Colors also can act as visual cues to separate workspaces or identify employee shift schedules, Kheradia said, giving the example of blue aprons being used by the first shift and orange aprons for the second shift; white tools could be used in the processing area and green tools at storage area; and so on.

“In this way, companies can account for item usage, and reduce misuse of tools in unapproved areas. Moreover, color-coding help can distinguish specific cleaning and sanitation zones,” he said. Black is a common color to identify cleaning tools used on floors and around the drains. Other colors can be used for food-contact tools that, say, handle different allergens which require cleaning and sanitizing. “This practice of segregating tools for food-contact and non-food contact surfaces helps prevent the undesired occurrence of using powerful cleaners on the wrong equipment,” he said.

Perfex Corporation Marketing Director Mike Dougherty provided five additional tips for color-coded tools:

• Keep it simple. Color assignments should be logical and not complex.
• Be consistent. Keep colors consistent in how they are applied.
• Consider contrast. Colors should be easily recognizable among food being processed so the tools can be easily identified when lost or misplaced.
• Communicate your program. It’s critical to make sure all employees are on board. To help assure compliance, some employers recommend meeting with shift employees first, then rolling out the program to all employees.
• Keep it clean. Clean and/or disinfect brushes after every use. Store brushes on a tool-mounting rack for proper air drying.
6. Establish a tool care and maintenance plan. To minimize the risk of cleaning tools becoming a source of potential contamination, food facilities should ensure they are appropriately cleaned, sanitized, and maintained. In part, Kheradia said, that means that decontamination methods for cleaning tools must be validated, monitored, verified, and reviewed when any changes to the cleaning parameters significantly change. These methods could be greatly influenced by the surface to be cleaned, type of contamination, risk level of the food being produced, type of environment (whether wet or dry), frequency and depth of clean, and type of consumer being served, he said.

Very few companies have a written tool care, maintenance, and replacement plan for their cleaning brushes, material handling utensils, or other tools, he added, but at the very least tools must be stored appropriately on shadow boards or racks with heads facing down and distant from other handles, in a single row; they should be replaced when worn out; and they need to be regularly cleaned and sanitized, as appropriate.

7. Develop good SSOPs and visual aids for training. It is important to develop comprehensive and communicable Sanitation Standard Operating Procedures (SSOPs) that can be easily understood and followed by the sanitation crew. The SSOP should define the purpose and scope, responsibility, detailed procedure or activity that defines the method, tools, chemicals used, monitoring procedure, corrective action procedure, verification procedures, supporting records and references, and revision history. Employees also must be formally trained on cleaning and sanitation activities with regular refresher training, Kheradia said.

When developing sanitation controls in compliance with FSMA, the potential hazards of both cross-contact of allergens and cross-contamination from unsanitary objects, personnel, or raw goods need to be considered. One best practice is to separately define the hazards of each; determine areas of overlap; and then set up your program to ensure it addresses each type of potential contamination while maintaining efficiencies in areas of overlap.

The author is Editor of QA magazine. She can be reached at llupo@gie.net.