Sanitizing as part of preventive controls is a requirement of food processing facilities. But, when microorganisms like E. coli, Listeria, Salmonella, Staphylococcus Aureus and others persist, chlorine dioxide gas may be the best kill step for resetting the environment.

Without question, a food facility’s primary responsibility is to ensure product safety, with effective sanitizing post-cleaning a significant part of FDA-required preventive controls. After ridding surfaces of dirt, allergens and harmful organisms, the sanitizing kill step must be safe to use and leave no undesired odors or residues that could encourage harborage of the very types of organisms they were designed to eliminate. 

But, sometimes even after routine cleaning and sanitizing, harmful organisms can linger, lurking in drains or hiding in the crevices of equipment. When swab counts increase and vectoring becomes a problem, the most prudent next step is resetting the environment with a deep penetrating sanitizer. Chlorine dioxide gas may be the solution.

Chlorine dioxide gas is a non-corrosive, antimicrobial problem solver that brings plants back to sanitary conditions without introducing moisture into the environment, says Jared Torgeson, vice president of business development at Pureline. It is effective across a wide range of applications including disinfecting food equipment, food contact surfaces, aseptic processing and as a treatment for agricultural washes. Chlorine dioxide is used to disinfect produce, cheese and milk products, bakery and poultry products, and more.

importantly, it does all this while meeting the regulatory requirements of Food and Drug Administration’s (FDA), the Environmental Protection Agency (EPA), the Occupational Safety and Health Agency (OSHA) and the U.S. Department of Agriculture’s National Organic Program (USDA NOP). 

FDA Sanitation Controls
FDA mandates “sanitation procedures for food contact surfaces and utensils and food-contact surfaces of equipment such as contamination and allergen control as part of a Hazard Analysis,” per the regulation 21 CFR 117, current Good Manufacturing Practice Hazard Analysis and Risk-based Preventive Controls for Human Foods, also known as the Food Safety Modernization Act (FSMA).

With so many sanitizer solutions available, each with their own benefits, risks, and effectiveness under a facility’s given conditions, choosing the right product can be challenging. When the need to reset an environment is required, the criticality of which sanitizer to use becomes exponential.   

A sanitizer’s effectiveness and ability to eliminate and inhibit biofilm formation is dependent upon factors including it’s pH, the temperature and mineral content of incoming water, the amount and type of microbial load, contact time with the surface being sanitized and the complexity of the equipment’s surface area (ie – intricacy of design and ability for the solution to penetrate hard to reach areas). 

Chlorine dioxide is a powerful gas with about 2.5 times the oxidation capacity, for instance, of chlorine. In addition to applications in the food industry, it is approved for use in some FDA-regulated consumer products such as toothpaste and mouthwash, further demonstrating its safety under approved use and conditions.

EPA & OSHA 
The EPA and OSHA add additional regulatory requirements for sanitizing products including chemical registrations, safety and instructions, and any Personal Protective Equipment (PPE). With more than 4,000 EPA-registered sanitizers and hundreds of active ingredients, the decision for which sanitizer is a best fit for purpose can get complicated very quickly.

Disinfection byproducts produced by sanitizers is one of the concerns. Unlike chlorine and ozone, chlorine dioxide gas produces no carcinogenic chlorination by-products nor by-products like bromates. 

Preparation of chlorine dioxide precursor chemicals does require PPE and proper protocols must be followed both while preparing the area for sanitizing and during the actual sanitizing itself. Preparations include taping doors and other openings wher chlorine dioxide gas might escape during the sanitizing cycle and staying out of the area until sanitization is complete and the air quality returns to an OSHA mandated 0.1 ppm safety level. 

Provided instructions for storage and use are followed, chlorine dioxide can be safely used and the facility will be ready to reenter and work resumed in approximately eight hours after sanitizing is initiated. “Chorine dioxide breaks down on its own,” says Torgeson, indicating that no additional equipment or facility air filtration beyond the HVAC systems already in place in are required to help remove the gas.

USDA’s National Organic Program
Facilities operating within the confines of the USDA’s National Organic Program (NOP) must scrutinize their sanitizer product choices. Some sanitizers are designed to leave a faint anti-bacterial residue on food contact surfaces. Unlike cleaners which are designed to be rinsed away after use, USDA organic regulations prohibit foods from coming into contact with any sanitizer residues. Additionally, USDA’s 7 CFR 205.605 regulation prohibits some synthetic sanitizers from being used on Food Contact Surfaces. Chlorine Dioxide gas is an acceptable sanitizer under USDA’s NOP. 

The Last Line of Defense
Whether post-construction, post outbreak or post-regularly scheduled intensive building maintenance. The key to successful sanitization is to start with a thoroughly clean surface. Cleaning removes dirt, debris, residues and harmful microorganisms. From there, sanitizers can do their work.

An oxidizing biocide, chlorine dioxide sanitizes by penetrating the cellular wall of targeted microorganisms, effectively killing them across a range of pH levels. Generated onsite from precursor chemicals, chlorine dioxide is less corrosive than chlorine bleach, has a low environmental impact and is not abrasive for electronics.

Chlorine dioxide will not affect food taste. It breaks down harmful DNA quickly with limited water and organic material interactions. No residual residue means no requirement for rinsing.

Chlorine dioxide is a very effective kill step, reaching hard to access surface areas. “If you have a serious issue in your facility, this is the tool to address the situation,” says David Blomquist, a food safety consultant who notes that chlorine dioxide is a very effective sanitizer post-recall.

Choosing the right sanitizer is one of the most critical aspects of ensuring safe food production, particularly during facility resets when combatting particularly persistent bacteria are necessary. As a last line of defense, chlorine dioxide, a long standing, effective solution, is a great place to begin and end your search.