When using process water, it is important that the water is clean and free of microorganisms. To achieve this goal, agents are needed to disinfect process water. Often, conventional disinfectants are used, but these often have adverse consequences. Consider the environment, but also the risks for the people using it [1]. 

Disinfecting process water

Process water often comes into contact with the product or production process, so risks to the end product or user must be excluded. Biofilms in process water can act as breeding grounds for pathogens and can reduce water quality [2]. Consequences of poor water quality can include premature spoilage or a bad smell or taste in the final product. This can lead to a recall. One step often taken to maintain water quality is process water disinfection. Conventional agents used for this purpose include chlorine dioxide (CIO2) and peracetic acid (C2H4O3). 

Health risks of conventional disinfectants

The use of conventional disinfectants has several risks. When used incorrectly by, for example, too low concentrations, disinfectants are not effective against biofilm [3]. But exposure to high concentrations has health risks. Using a concentrated solution of peracetic acid can lead to skin and eye damage. Also, some diluted solutions can cause irritation to the eyes and throat [4]. It is therefore always recommended to follow the instructions for use and safety precautions [5]. In addition, it is often wise to use personal protective equipment while working with these agents. The most common health complaints caused by using conventional disinfectants are irritation, tightness of the chest or other respiratory complaints. Of course, these health risks depend on the type of product and its use, and these effects are not identical for every disinfectant.

Consequences of exposure to harmful disinfectants

Many conventional disinfectants are toxic in direct contact with skin, eyes or when inhaled. Exposure to these substances can cause acute symptoms. Employees working with the disinfectant must therefore be careful for their own safety. Some examples of symptoms include burns, irritation of the skin and/or eyes and respiratory problems such as tightness of the chest and shortness of breath [6]. Another risk when using certain disinfectants is the formation of harmful disinfection by-products (DBPs). Applying a halogen-containing biocide can lead to this. This can, especially in high concentrations, pose a hazard to the user and the environment because it contains hazardous substances [7]. 

Effective alternative 

A disinfectant based on Hypochlorous acid (HOCl) is an effective alternative to conventional agents. This disinfectant is produced by putting a saline solution under electrolysis. HOCl is an endogenous substance produced in the white blood cells of most mammals. HOCl is part of the immune system to fight infections [8]. HOCl is effective against bacteria, fungi, yeasts and viruses, it is more effective at low concentrations than conventional agents [9]. Sustainable in-situ (on-site) production makes HOCl an alternative with less risk to the environment and employee health.

References: 

1. https://www.sciencedirect.com/science/article/abs/pii/B9780128243152006345
2. https://www.sciencedirect.com/science/article/abs/pii/S0924224409000557
3. https://digitaalmagazine.evmi.nl/hygienespecial-2020/heldere-conclusies-bij-onderzoek-naar-verneveling/
4. https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Peroxyacetic-Acid.pdf
5. https://www.biociden.nl/desinfectie
6. https://www.kennisnetwerkbiociden.nl/nieuws/desinfectie-met-perazijnzuur-veroorzaakt-gezondheidsklachten
7. https://www.ctgb.nl/biociden/aanvraag-indienen/afwijkende-producten/disinfection-by-products
8. https://link.springer.com/article/10.1007/s00018-020-03591-y
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC4964533/