Chlorine

How is chlorine allowed for use as a sanitizer in organic handling?

By Amber Lippert

In nature, chlorine is widely found in seawater in the form of the salt, sodium chloride (NaCl). Compounds of chlorine also occur as minerals in the Earth’s crust. It was not until the year 1810 that chlorine gas was added to the periodic table as an element in the halogen family - the least metallic and most highly reactive group of elements. Chlorine reacts directly with nearly all other elements, and forms salts called chlorides when mixed with metals. In fact, the name halogen means salt producer.

Chlorine gas is prepared commercially by passing electricity through a water solution of sodium chloride or through molten sodium chloride. By mixing chlorine gas with sodium hydroxide, one can create sodium hypochlorite. Chlorine dioxide can be produced by the reaction of sodium hypochlorite with hydrochloric acid. Calcium hypochlorite (bleaching powder) can be made by treating calcium carbonate with chlorine gas. When consumers buy a gallon of household bleach at the grocery store, they are generally buying a 5.25% solution of the chemical sodium hypochlorite mixed with water.

With regard to handling, the National List of Allowed and Prohibited Substances at 205.605(b) states that certain chlorine materials, including  calcium hypochlorite, chlorine dioxide and sodium hypochlorite, are allowed for disinfecting and sanitizing food contact surfaces, “Except, That, residual chlorine levels in the water shall not exceed the maximum residual disinfectant limit under the Safe Drinking Water Act.” Furthermore, the National Organic Program (NOP) clarified in their September 2015 Policy Memo 15-4 that electrolyzed water is also permitted as a type of chlorine material in accordance with the National List.

Organic certifiers, farmers and handlers have questioned how the chlorine content of waste water should be measured, and whether chlorine materials are allowed to have direct contact with certified organic foods. Historically, many certifiers and OMRI required that measures be taken to prevent contact of the organically produced products or ingredients with the chlorine substance during handling.

To clarify use of chlorine in organic production and handling, the NOP published Guidance 5026 in July of 2011. The Guidance clarified that processing operations must demonstrate compliance with the chlorine annotation by monitoring the chlorine content of the water which is in direct contact with the organic products, not the flush water discharged from the facility. Each form of chlorine material has a different standard under the Safe Drinking Water Act (SDWA). The maximum residual level for chlorine is 4 ppm, or .08 ppm for chlorine dioxide. Take caution and follow all label instructions when using chlorine materials in amounts greater than allowed by the SDWA. At only 15 ppm, Sodium hypochlorite can cause skin and throat irritation.

NOP Guidance 5026 clarifies that chlorine materials may be used for disinfecting and sanitizing food contact surfaces when used up to maximum labeled rates, and rinsing is not required unless mandated by the label use directions. For direct contact with the crops or food, including wash water in produce lines, chlorine materials are permitted at levels approved by the Food and Drug Administration (FDA) or the Environmental Protection Agency (EPA) for that purpose. However, after sanitizing with the chlorine material, the organic food must be immediately rinsed with potable water that does not exceed the maximum residual disinfectant limit for the chlorine material under the SDWA. Chlorine materials used in breaker eggs (eggs that are further processed prior to retail sale and not sold to consumer in the shell), are exempt from the requirement to rinse, and must comply with Food Safety and Inspection Service regulations, as required by NOP Policy Memo 14-2.

Today, chlorine is one of the top ten products mass-produced by the U.S chemical industry. Alternative sanitizers for use in organic production include peracetic acid, hydrogen peroxide and sodium hydroxide in accordance with their respective listings on National List. See the OMRI Products List© to find allowed products. Producers and handlers of certified organic food should check with their certifier prior to incorporating a new product into their Organic System Plan.

Revised and updated in January 2016 by OMRI Technical Director Johanna Mirenda. This article was originally published in the Summer 2012 edition of the OMRI Materials Review newsletter.