Is Sodium Hypochlorite The Best Way To Treat Water For The Food Industry?

Is Sodium Hypochlorite The Best Way To Treat Water For The Food Industry?

Is Sodium Hypochlorite The Best Way To Treat Water For The Food Industry?

Is Sodium Hypochlorite The Best Way To Treat Water For The Food Industry?

Sodium hypochlorite (NaOCl) is a greenish-yellow liquid produced by combining chlorine and sodium hydroxide. Commercial sodium hypochlorite is manufactured by adding chlorine gas to caustic soda, which produces sodium hypochlorite, water and salt. Alternatively, when smaller amounts are required, sodium hypochlorite can be produced on site by dissolving salt in softened water. This results in a concentrated brine which can be electrolyzed to form a sodium hypochlorite solution.  

How is Sodium Hypochlorite currently used in the food industry?

Sodium hypochlorite has many applications in agriculture, food and beverage industries. Sodium Hypochlorite maintains water quality through oxidation or disinfection. It destroys harmful microorganisms and prevents algae or shellfish from growing in stored water. It’s an essential component in many sanitisation processes, including washing fruits and vegetables, and the preparation of meat and fish for consumption. As it’s the main ingredient in household bleach, it’s used on factories and farms for cleaning and disinfecting equipment. It’s widely used to disinfect potable water and wastewater in certain countries.  It’s an effective treatment for private water supplies from boreholes, also called wells, and where water is stored prior to use in industry.

How does Sodium Hypochlorite work as a disinfectant?

Sodium hypochlorite functions as a disinfectant in a similar manner to chlorine and is very effective against viruses, bacteria and fungi as it strips away microbial cell walls and renders nucleic acids non-functional, preventing these organisms from reproducing. When added to water, it forms hypochlorous acid (HOCl) and a chlorite ion (OCl-) otherwise known as free chlorine. 

The ratio between HOCl and OCl- depends on the pH and the temperature of the water. At 25°C and pH 7.5, the chlorine is divided equally between HOCl and OCl-. It may be necessary to acidify the water as part of the process in order to get the desired proportions – ideally with more hypochlorous acid in the mix as this is the best disinfectant. As the hypochlorite ion is negatively charged, it bounces away from microbial cell walls, which are also negatively charged. The chlorite ion is also bigger than the HOCl molecule so it diffuses more slowly. Hypochlorous acid is usually the best option as it’s a stronger oxidising agent than the hypochlorite ion.

Hypochlorous acid degrades rapidly when it comes into contact with organic matter so it does not have a lasting environmental impact. As with other forms of chlorine, regular testing of the pH and chlorine levels in treated water is necessary to ensure that local quality standards are being met. 

What precautions should be taken when storing commercially available Sodium Hypochlorite? 

The sodium hypochlorite solution normally available from chemical suppliers is safer and more convenient to store than chlorine gas, but it breaks down if exposed to sunlight, high temperatures, or vibrations. When it’s stored for a long period of time the solution degrades, so good stock management is essential. The higher the original concentration of the solution, the more rapidly it breaks down. It should be stored in a cool room in an opaque (ideally black) container. Sodium hypochlorite is caustic and can irritate, even burn, the eyes and skin on contact, so it needs to be handled by trained staff using protective gear.

The need for controlled storage is one of the main drawbacks of using Sodium Hypochlorite, along with the health and safety protocols involved. It can be difficult and expensive to store large amounts over time. In order to maintain standards, an agricultural production company might need to keep large quantities of other chemicals like chlorine dioxide and peracetic acid on site for washer disinfection. This means placing regular orders with a chemical supplier, costing upwards of £100K per annum.

Is there an alternative to bulk storing Sodium Hypochlorite?

At Prodose, we have developed a unique electrochlorination system that uses common salt, water and electricity to dispense a low pH Sodium Hypochlorite into your water supply as and when required. No hazardous chemicals are needed for this reaction, so storage isn’t a problem. It’s a much safer process than chlorination using commercial sodium hypochlorite as the solution remains below the 5% concentration threshold considered hazardous by the UK Health and Safety Executive. 

Our electrochlorination systems are geared to the size of your operation and range in dosing levels from 100 grams per hour up to 10 kilograms per hour. This simplifies the production process with increased automation, saves on running costs (chemicals cost around £10K per annum), and improves efficiency. We’ve installed these electrochlorination systems in a wide range of facilities, including cleaning in place (CIP) for a leading soft drinks company.

To learn more about the latest water treatment techniques, including alternatives to Sodium Hypochlorite, please contact the team of expert chemical engineers at Prodose. We specialise in developing unique solutions to your water treatment problems, and electrochlorination may well be the technology you’re looking for.

If you are interested in upgrading your system in this way, please get in touch with us at Prodose. We’d be very happy to talk to you confidentially and on a no-pressure basis.

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What part does chlorine play in food safety?

What part does chlorine play in food safety?

What Part Does Chlorine Play In Food Safety?

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? 

We’ll discuss the advantages of this process further in future posts. Make sure you’ve subscribed so you don’t miss them.

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.

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If you are interested in upgrading your system in this way, please get in touch with us at Prodose. We’d be very happy to talk to you confidentially and on a no-pressure basis.