Personal Hygiene is Critical for Food Safety Programs

Regarding handwashing practices to remove norovirus, it’s been shown that antibacterial hand soaps plus water with vigorous rubbing remove the most viral particles. While the alcohol-based hand sanitizers are highly effective against bacterial pathogens, studies have found them to be minimally effective on viruses like Norwalk and other enteric viral pathogens.

What biocides are effective on pathogenic viruses on environmental surfaces? A study done in 1990 by Syed Sattar’s group and published in Applied and Environmental Microbiology screened common disinfectants and found 2 percent glutaraldehyde, 5,000 parts per million hypochlorite (bleach), and an acidic QAC product (toilet bowl cleaner) were all effective, while liquid alcohol, peracetic acid, and other organic acids were ineffective in reducing Hep A. While a high bleach concentration is effective for many plant surfaces, that level can be corrosive with persistent use. Also the type of food contact or environmental surface—non-porous versus porous, hydrophobic versus hydrophilic—strongly factor in disinfection efficiencies. It’s also difficult to quantify virucidal or bacterial efficacy on porous environmental surfaces. The elimination of as many porous surfaces in washrooms and within the food plant, including porous worn food contact belts, is critical.

Many studies have focused on human non-gloved hands as being the primary culprit in Norwalk virus transmission. Another study published in Applied and Environmental Microbiology proved even non-infected, symptom-free workers become unsuspecting carriers, at an average of nearly 4 log cycles of Norwalk virus per hand. This proves the need for a complete hand hygiene program in both the office and food handling areas. But keep in mind that glove use does not negate proper hand hygiene practices—it complements it.

Pathogens like Salmonella spp. survive well for long time periods in dry environments, including restrooms and sinks. However, when proper cleaning followed by EPA-approved sanitizers are used, Salmonella can be controlled in all areas. Shigella spp. is also a major concern regarding improper hand hygiene and environmental sanitation of hand sinks and washrooms. A recent study in the Journal of Food Protection inoculated 5 to 6 Log cycles of Shigella on hands followed by proper handwashing then by preparation of melon balls to track the level of contamination. Antibacterial soaps achieved 3 to 4 Log cycle reductions, but the standard soaps had roughly a 2 log reduction, resulting in greater Shigella levels on the melon balls. This data is applicable for all enteric bacterial pathogens and proves the greater need for more quantifiable risk assessments on handwashing. Other quantification studies have involved handwash duration, type of hand soap, level of soiling, and drying methods using a reliable pathogenic surrogate, Enterobacter aerogenes, in the model soil. The proper usage of hand soap with rinsing resulted in a greater microbial reduction (roughly 99 percent reduction) than when water alone was used. Also, it was confirmed that utilization of disposable paper towels provided more physical agitation versus air drying.

Restroom Issues and Recommendations

While it’s been discussed that using cleaning cloths can transfer and contaminate hands and surfaces with pathogens, can the same be applied to disinfectant wipes commonly utilized in washrooms, offices, and inside food plants? A study in Applied and Environmental Microbiology quantified microbial transfer from a contaminated surface to QAC-based disinfectant wipes to employee fingers. It was found that the levels of S. aureus, E. coli, Bacillus, and poliovirus were markedly reduced on the subjects’ fingers from ceramic tile, laminate, and granite when the disinfectant wipe was employed.

According to the USDA FSIS Sanitation Performance Standards Compliance Guide, toilet facilities must be:

• Adequate for the current number of employees in facility,
• Sanitary and in good repair,
• Employing self-closing doors that do not open into food area,
• Adequately ventilated and not have offensive odors,
• Using lockers that are regularly emptied and cleaned and periodically fumigated, and
• Free of old clothes and trash.

Hands-Free EZ Hand Sanitizer Dispenser.