What Part Does Chlorine Play In Food Safety?

21st century food production, processing and delivery relies on a constant source of clean water to disinfect machinery, containers, work surfaces and the products themselves. This prevents the spread of foodborne diseases.

Chlorine is highly valued across the food and beverage industry and agriculture as one of the most effective ways to treat water supplies and maintain hygienic standards.

Most people are familiar with the pungent odour indicating a chlorine solution has been used in the immediate area. Although it seems ubiquitous in our everyday environment, this highly reactive gas doesn’t occur naturally. It’s found in thousands of chemical compounds, including common substances such as salt (sodium chloride), sylvite (potassium chloride) and carnallite (potassium magnesium chloride hexahydrate).

At Prodose, our team of chemical experts advise on and implement the use of chlorine compounds to treat water in a wide range of food safety applications. In agriculture, chlorinated water irrigates fields and livestock sheds, lowering the risk of contamination at source. In fruit and vegetable processing plants, chlorine solutions wash the product prior to packaging. In restaurants and supermarkets, chlorine-based compounds such as bleach are used to clean equipment to protect both workers and customers.  Each business uses treated water in a different way and we specialise in providing the most efficient system to meet your unique disinfection needs.

How does Chlorine prevent the spread of disease?

Foodborne diseases such as typhoid fever, dysentery, cholera and Legionnaires’ disease are caused by microbial pathogens that live in water. When it comes into contact with these microorganisms, Chlorine damages their cell walls, preventing the pathogen from functioning or reproducing.

How does Chlorine react with water?

Chlorine can be added to water in any one of its three forms, depending on the strength of the disinfectant required. The strength of the chlorine compound is known as “available chlorine”, as this is the amount available for the chemical reaction:

• Liquid (in the form of sodium hypochlorite), around 12-16% available chlorine;
• Solid, in the form of powder, granules, or tablets, made from calcium hypochlorite (65-75% available chlorine), chlorinated isocyanurates (variable) or lithium hypochlorite (35% available chlorine);
• Gas (highly toxic and only used under special conditions) 100% available chlorine. 

When chlorine or a chlorine compound is added into water it releases hypochlorous acid, HOCl. The hypochlorous acid commonly disassociates into other forms, such as the chlorite ion, OCl–, depending on the pH of the water. The amount of chlorine in the water in these forms is referred to as Free Chlorine. The reaction of chlorine with organics to form compounds such as chloramines is referred to as combined chlorine. 

The sum of Free Chlorine + Combined Chlorine is known as Total Chlorine. 

In some applications, where the water contains many organics, such as swimming pools, it’s useful to monitor Free and Total Chlorine levels on a regular basis to ensure that the quality of the water meets local standards.

Which chlorine compound is most useful to the food industry? 

There’s a lot of demand for chlorine dioxide, which is considered a highly cost-effective, environmentally friendly, and potent antimicrobial agent for use within the food industry. Even at low concentrations, it destroys the pathogens that sometimes cling to fruits or vegetables, and prevents any regrowth of bacteria, viruses, yeasts, and moulds, extending the shelf life of these products quite significantly. Large quantities can easily be produced on site, so it’s an ideal choice for plants producing pre-prepared foods such as bagged salads. 

Are Chlorine compounds the only option for disinfecting water in the food industry? 

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Prodose’s team of chemical engineers have years of experience advising on the installation of water treatment systems for the food industry. We offer a wide range of disinfection products to fit every chlorination need. We’re continually pushing forward with new technologies that minimize onsite storage of chemicals and limit the amount of human interaction needed to keep systems running. If you have questions about improving the efficiency of your existing system, or want to install a state-of-the-art clean water supply for your agricultural location or food processing plant, please get in touch.