Food Safety Magazine

SIGNATURE SERIES | March 25, 2013

Workwear Solutions for Food Product Safety

By Fran McAteer, M.Sc., MBA

Workwear Solutions for Food Product Safety

When food is your business, product safety is a non-negotiable. Careful controls are critical to minimizing cross-contamination risks and achieving regulatory compliance. That’s also where Hazard Analysis and Critical Control Points (HACCP)/Global Food Safety Initiative (GFSI) plans are necessary—to help prevent contamination within food manufacturing, processing, distribution and retail operations, and to ensure the general safety of food products.

The U.S. Centers for Disease Control and Prevention (CDC) calculates that there are approximately 76 million cases of foodborne illnesses annually, resulting in 325,000 hospitalizations and 5,000 deaths. According to the CDC, about one in six Americans comes down with a foodborne illness every year. In response, federal regulatory agencies aggressively monitor, revise and upgrade national food safety requirements. Developing and implementing an effective and up-to-date HACCP/GFSI plan is recognized as an important precaution for all food industry managers.

Waves of well-publicized recalls of potentially contaminated foods have raised ongoing concerns that some food items consumers eat may not be safe. To help alleviate these worries, the United States government adopted the Food Safety Modernization Act (FSMA) in 2011. FSMA aims to ensure that the U.S. food supply chain is consistently safe by shifting the focus from reacting to contamination incidents to preventing them. This legislation empowers the U.S. Food and Drug Administration (FDA) to inspect and audit the quality systems of food manufacturers, processors, distributors and retailers. Inspectors investigate potential contamination risks in such organizations and can mandate full product recalls (a step that was “voluntary” prior to FSMA). As a result, food facilities such as meat processors, butchers, dairies, groceries, restaurants and the like are required to evaluate all potential hazards in their operations, implement and monitor effective measures to prevent possible contamination, and have a detailed plan to take corrective actions as necessary.    

UniFirst UniSafeSM Service for Food Facilities
Work garments worn by food industry employees need to be maintained, processed and managed effectively so they are not a potential source for food contamination. To address this need, UniFirst Corporation, a uniform service and supply company operating throughout the U.S. and Canada, developed UniSafe Service for food facilities. The goal of this specialized garment safety program is to effectively eradicate bacterial contaminants that can colonize on food employee workwear.

The UniFirst UniSafe Service program includes a portal-to-portal process, called the Product Protection Process (PPP), designed to prevent cross-contamination from uniforms and other worker garments. The UniFirst PPP begins at customer facilities and extends throughout all garment handling, laundering and finishing procedures to deliver clean, sanitized garments to food-related workers on a regular schedule. The program is based on principles set forth in HACCP and GFSI application guidelines, and identifies and mitigates risks involved with the process. All garments are sorted, washed, sanitized and poly-bagged (optional) using UniSafe Standard Operating Procedures (SOPs), with CCPs defined and constantly monitored to ensure effectiveness of cross-contamination controls. This proprietary program has been instituted in all UniFirst servicing plants, and all UniFirst personnel involved in the processing of food-related customer garments receive comprehensive HACCP/GFSI training.

The UniFirst PPP has three main stages where microbial contamination is eliminated: HACCP/GFSI wash cycle, dryer cycle and steam tunnel finishing/garment pressing finishing.

The poly-bag stage is an additional preventative measure to help protect cleaned garments from exposure to environmental contaminants after processing, throughout the delivery process and prior to being worn. Once the garments have gone through the full PPP, they’re loaded onto a delivery vehicle and transported back to UniFirst’s customer.

UniSafe Service begins with the delivery of clean garments and the pickup of soiled ones from the customer facility. Soiled garments are brought to the transport vehicle and loaded into segregated plastic liners. Soiled items are then transported to a UniFirst facility to undergo the complete HACCP/GFSI wash process that consists of four defined CCPs:

•    Soiled garments segregated and stored in slings/hampers; staged in preparation for washing

•    Garments undergo UniFirst’s HACCP/GFSI wash process, consisting of 160 °F water (minimum), chemical cleaner injection, 10–15% bleach solution and 25-minute wash time

•    Ten-point quality inspection of all garments and garment finishing

•    Finished garments prepared for redelivery (poly-bagged, if desired), consistent with  customer requirements

UniSafe Processing Steps
Loading the route vehicle for delivery: Truck loaded with appropriate segregation containers, bags and clean garments.

Delivery of hygienically clean garments: Clean (poly-bagged) garments are delivered to designated area at customer site.

Pickup of soiled garments: Soiled garments are placed in plastic bags and put on route truck in segregated containers/bins.

Return to UniFirst plant: Soiled garments are transported to a UniFirst laundry plant.

Unloading soiled garments: Garments are sorted, identified as “food related” and segregated in appropriately designated slings.

Wash and dry: Slings loaded with identified “food related” soiled garments are brought to wash aisle and laundered with specified HACCP/GFSI wash process and cleaning formula at a minimum of 160 °F. After wash cycle, items are loaded into dryers for garment conditioning.

Inspection and garment finishing: All hygienically clean garments undergo 10-point quality inspections; “passed” garments go through minimum 270 °F steam tunnel or garment press. “Failed” garments are routed for mending or replacements.

First sort: All garments are segregated and sorted by delivery schedule, customer and wearer using proprietary bar code scanning technology.

Final delivery of hygienically clean garments: Finished, sorted garments (optionally poly-bagged) are safely segregated and transported from plant to designated site at customer location or UniFirst branch facility for final customer delivery.

Laboratory Tests
To measure the effectiveness of the UniSafe Service (and PPP) as a HACCP/GFSI uniform program process, we needed to determine if it is an effective pathogen reduction methodology in the laundering and processing of soiled food industry work garments. To scientifically measure this, UniFirst turned to Environmental Monitoring Associates, Inc. (E/M Associates or EMA) for an objective laboratory study.

EMA is an independent microbiology consulting service and Good Manufacturing Practices (GMPs) laboratory with expertise in contamination controls for the food industry. EMA developed and executed a formal protocol based scientific lab study to assess the microbiological contamination controls used by UniFirst in its UniSafe Service and HACCP/GFSI uniform program. The study complies with ISO 14698 Annex D and E Biocontamination Control of Laundry Services, and was based on HACCP, GFSI, ISO and FDA food safety guidelines and requirements.

The following is a summary of the study by EMA to evaluate the ability of the UniSafe Service to reduce and control microbial contamination during the laundering, processing and delivery of food service work garments. Example items include soiled uniforms, coats, shirts, pants, towels and aprons. Bacterial cross-contamination from all these sources is a known cause of concern for both UniFirst and its many food industry customers. This scientific laboratory analysis was commissioned by UniFirst to quantify pathogen reductions within the company’s UniSafe Service and PPP.

Testing Strategy
The microbiological tests conducted were designed to assess the microbial load reduction capabilities of UniFirst’s UniSafe Service. The tests conducted represent an exaggerated contamination scenario, as garment samples were inoculated with excessive quantities of bacteria (approximately 1 million). Fabric swatches were used to localize the bacterial inoculation more readily and to make laboratory sampling more accurate. The swatches were made of the same materials as their host garments in order to remain consistent with actual process conditions. Five indicator organisms were chosen to represent different kinds of bacterium and pathogens that are common sources of contamination within the food industry and are often detected in such environments. The five test organisms were used to challenge the three main stages of the PPP where microbial contamination is eliminated:

•     HACCP/GFSI wash cycle
•    Dryer cycle
•    Steam tunnel finishing/Garment pressing finishing cycle

Bacteria, mold, and other microorganisms are commonly found contaminants within the food industry. The testing challenged the PPP CCPs with the following five microorganisms:

•    Escherichia coli: bacteria that is an indicator for meat/poultry contamination. E. coli has been the organism identified as the cause of many deaths and major food recalls

•    Enterococcus faecalis: a microorganism used as an indicator of fecal contamination

•    Saccharomyces cerevisiae: a potentially harmful yeast that is widespread in the baking and brewery industry

•    Aspergillus niger: a mold utilized in the dairy industry and represents wet garment contamination

•    Bacillus subtilis: a spore forming bacteria that is hard to kill and is usually an indicator for soil contamination

The five organisms were utilized for the microbial challenge as they are specified within ISO 14698-1:2003 (E) Annex E Guidance on Validating Laundering Process. They’re defined as “broad spectrum,” meaning they represent the most common types of microorganism contaminants found in the food industry. This further validates the relevance of this study with respect to garment decontamination. The different types of microorganisms our indicator organisms represented were the following:

•    Gram-negative rods (GNRs): represented by E. coli and includes the deadly E. coli O157:H7 pathogen. Other similar GNR pathogens include various Salmonella species and Camplyobacteri jejuni that cause potentially fatal gastrointestinal illnesses.

•    Gram-positive cocci: represented by E. faecalis. This is also indicative of Staphylococcus aureus, a causative agent of foodborne disease.

•    Yeasts: represented by S. cerevisiae. Yeast is the cause of various food spoilage issues.  

•    Molds: represented by A. niger. Mold contamination, like “black mold” and “green mold,” cause harmful respiratory issues and are responsible for a range of refrigerated product and beverage contaminations. Molds have sporulating and toxin producing abilities that can make them toxic.

•    Gram-positive rods: represented by the B. subtilis. This class of bacteria includes Listeria monocytogenes, Bacillus cereus and Clostridum botulinum, all known causes of potentially fatal food poisonings. This spore forming bacteria is also used to validate sterilization of medical devices.  

Fabric swatches (25 cm2 area) were contaminated with the indicator organisms, attached to individual garments (matching fabric types), and put through each step of UniFirst’s UniSafe Service. After the steps were completed, the swatches were collected in separate sterile bags, brought to the EMA lab, and tested using a bioburden recovery method to determine how many bacteria from the original contamination remained. In addition, the optional poly-bag packaging for the final shipping process point was tested by pressing a nutrient media on five different points of garments immediately after the poly-bag step. This test was designed to detect and quantify how many, if any, microorganisms were remaining on the garments after going through the entire UniFirst PPP.

The challenge microorganisms utilized in the UniSafe efficacy study portray and exhibit similar lethality profiles when exposed to the PPP’s critical processes, as do most food pathogens, as outlined in the FDA’s Bad Bug Book (an official FDA handbook that provides facts on food-borne pathogenic microorganisms).

Standard methods for food and dairy microbiological testing were utilized for inoculation, detection, enumeration and identification.  These included the following:

•    Pour plate methodology
•    Colony morphology and automated identification
•    Bioburden recovery method validation
•    Membrane filtration techniques
•    Heterophilic plate count

All methods were validated beforehand to demonstrate that repeatability, accuracy, precision and robustness were consistent.

Each PPP step was found to kill over one million pathogenic organisms, demonstrating UniSafe Service consistently reduces harmful bacteria levels on soiled foodservice garments. The sterilization lethality constant, also known as sterilization assurance level (SAL), also showed the required quantifiable level of microorganism reduction for a product to be deemed sterile by regulatory bodies; ISO 14698-1:2003(E) Annex E Guidance on Validating Laundering Process and ISO 11137 Sterilization of Health Care Products by Radiation.

The validation testing challenged inherent intrinsic parameters of UniFirst UniSafe Service and garment processing to demonstrate quantifiable microbial contamination reduction in the wash and bleach formulas, cleaning temperatures, drying temperatures and times, steam tunnel/garment press finishing temperatures and dwell, and poly-bag final packaging. Each critical process has a significant impact on killing bacteria from worn garments. In fact, the cumulative effect approaches sterilization (100% kill rate). This is a clear advantage of UniSafe Service. It provides redundant microbial lethality ensuring the hygienic cleanliness of garments, no matter how soiled. This formal study provides UniFirst and its customers proven methodologies based on GMPs that show definitive pathogen reduction from garment processing and highlights the microbiocidal effectiveness of this system for effectively processing food-related garments.

The study results show the risk reduction of microbial contamination in the processing of food-related garments. The microorganisms are killed in very significant quantities by the washing, drying and steaming operations as depicted in the CCPs and the entire PPP. The microbial lethality of the PPP is exhibited across various types of microorganisms from bacteria to yeast to molds.  The broad-spectrum microbial lethality of the UniSafe Service, as demonstrated in this study, indicates that various contaminants, whether blood-borne pathogens or viruses from the meat, dairy, beverage, bakery or other products, will be effectively eliminated (killed).  

The lethality efficiency of the UniSafe Service is further exhibited on the individual challenge organisms. The initial challenge levels of these organisms were between 2.4 million and 210 million CFU.  The recovery after UniSafe processing was between 15–40 CFU. This plainly demonstrates how the UniSafeSM Service eliminates broad-spectrum bacteria and fungi that represent the majority of foodborne pathogens.

Test results demonstrated that soiled/contaminated food preparation garments can be laundered, serviced and returned to clients both hygienically clean and pathogen free as a result of the inherent bacteriocidal properties of the UniSafe Service program.

The UniFirst UniSafe Service program is a systematic preventative approach to controlling potential microbiological hazards in food supply safety and works effectively to reduce microbiological contamination to levels approaching virtual sterility (reduces bacterial contamination levels on workwear by >99.9999%).
This study measured, monitored and documented the effectiveness of the UniSafe Service program and demonstrates the UniFirst PPP is a consistent pathogen reduction methodology for laundering and processing soiled food-related work garments. Food-related businesses now have a scientifically proven choice for effective garment disinfection consistent with their food safety goals.

Fran McAteer, M.Sc., MBA, is the President of E/M Associates, Inc. His expertise is in disinfection efficacy, sterilization validation, cleanroom manufacturing, HACCP/GFSI assessments and environmental monitoring. He has been involved with GMP quality systems and testing, and technical affairs in pharmaceutical media devices, foods, beverages and textiles for more than 25 years and his articles have been published in numerous trade magazines and publications.