“Cleanliness is next to godliness.”
Explore this issueOctober/November 2009
Across the food industry, legions of plant sanitarians would swear they could comfortably retire if they had a sawbuck for every time they have heard this axiom. While battle fatigue associated with this oft-used adage is understandable, its underlying message—that effective cleaning and sanitizing are essential prerequisites for producing safe, quality food—remains at the core of sanitation training programs.
Sanitizers are generally defined as chemical, thermal, or radiation treatments that are used to disinfect, reduce, or mitigate the growth of microbial contaminates to levels that are considered safe from a public health standpoint. Under U.S. federal regulations, chemicals sold as sanitizers must kill 99.999% of 75 million to 125 million non-pathogenic Escherichia coli and Staphylococcus aureus bacteria during a 30-second exposure at 68°F.1
Due to their widespread popularity, chemical sanitizers are a critical component of plant sanitation programs. Accordingly, these programs should devote ample attention to providing employees with in-depth, continuous training on the proper handling, application, and intended use of chemical sanitizers, particularly those used on food equipment and other product contact surfaces.
Nationwide, the Environmental Protection Agency administers the registration of chemical sanitizers and antimicrobial agents for use on food product contact surfaces. Ideally, chemical sanitizers should:
- be approved for food contact surface application;
- have a broad range or scope of activity;
- be stable under all conditions;
- be tolerant of a broad range of environmental conditions;
- be readily solubilized and possess some detergency;
- be low in toxicity and corrosivity; and
- be inexpensive.2
Over time, the U.S. Food and Drug Administration (FDA) has sanctioned several chemicals for use as no-rinse, food contact surface sanitizers in the processing environment. The fact sheet “Basic Elements of Equipment Cleaning and Sanitizing in Food Processing and Handling Operations” offers an extensive review of commercially available chemical sanitizers.2 It was written by Ronald H. Schmidt, PhD, of the Food Science and Human Nutrition Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. The following section, highlighting excerpts from the fact sheet, provides a brief overview of some common industry sanitizers.
In its various forms, chlorine is the most commonly used sanitizer in food processing and handling applications. Commonly used chlorine compounds include liquid chlorine, hypochlorites, inorganic chloramines, and organic chloramines. “Chlorine compounds encompass broad-spectrum germicides which act on microbial membranes, inhibit cellular enzymes involved in glucose metabolism, have a lethal effect on DNA, and oxidize cellular protein,” Dr. Schmidt wrote. “The activity of chlorine is dramatically affected by such factors as pH, temperature, and organic load. The major disadvantage to chlorine compound is corrosiveness to many metal surfaces (especially at higher temperatures). Health and safety concerns can occur due to skin irritation and mucous membrane damage in confined areas.”
Widely considered as a chlorine replacement, chlorine dioxide (CIO2) appears to be more environmentally friendly and has 2.5 times the oxidizing power of chlorine. “ClO2’s primary disadvantages are worker safety and toxicity,” Dr. Schmidt wrote. “Furthermore, its highly concentrated gases can be explosive and exposure risks to workers is higher than that for chlorine.”
Dating back to the 1880s as an antimicrobial agent, iodine exists in many forms—known collectively as iodophors—usually with a surfactant as a carrier. Like chlorine compounds, iodophors are effective against a wide range of bacteria, viruses, yeasts, molds, fungi, and protozoa. “Iodine is highly temperature dependent and vaporizes at 120°F,” Dr. Schmidt wrote. “Thus, it is limited to lower temperature applications. The degree to which iodophors are affected by environmental factors is highly dependent upon properties of the surfactant used in the formulation.”
Quaternary ammonium compounds (QACs) are the only sanitizer group that has true residual activity. In some food processing facilities, QACs are used to sanitize equipment prior to long periods when the equipment is not in use. Effective against bacteria, yeast, mold, and viruses, QACs work over a wide pH range, with best activity in alkaline pH. They are generally more active against gram-positive than gram-negative bacteria. QACs are not highly effective against bacteriophages. QACs can be incompatible with certain detergents, making thorough rinsing following cleaning a necessity.