Filtration Solutions to Ensure Bottled Water Safety 

High microbiological counts in bottled water affect the quality of your product, which can lead to safety, regulatory and/or recall issues. However, these risks and costs can be easily avoided by implementing an effective, high-quality water process with suitable microbiological treatment methods.  

In a recent Science Snippets blog post we looked at the growing global demand for bottled water and the resulting importance of high-quality water filtration and quality control for manufacturers looking to meet that demand and stay ahead of the competition. Following on from that post, we are now going to dig deeper into the crucial area of microbiological contamination that is a principal cause of quality issues, not to mention costly bottled water recalls, that will restrict your capacity to maintain and grow your share of the market as well as increasing costs and reducing profitability.

In addition, bottled water manufacturers are responsible for the safety of the water inside the bottle throughout its shelf-life (two years on average). Non-compliance with the regulations in your market obviously puts consumers at risk but it’s also bad for business. So, you will need to safeguard your production process from microbiological contamination throughout and be confident that you have the necessary quality controls in place.  

In this blog post, you will be able to navigate the different microbiological treatments available and see how filtration technology can help you build a high-quality, cost-effective process of your own. Last but never least, we have also added a resource with links to the all-important regulations and standards to be aware of in your markets. 

Microbiological treatments: what are your options? 

Firstly, let’s take a look at the different treatments that are relevant to the bottled water industry and its high demands on quality and safety. Each with a brief summary, these are: 

• Membrane filtration 

Membrane technology is used to filter out particles larger than 0.2 μm as well as the majority of micro-organisms present in water such as cysts (Giardia and Cryptosporidium parasites) and bacteria. The microorganisms are filtered out because they are trapped due to several mechanisms: direct interception depending on pore sizes, adsorption, inertial impact against the media. 

• UV disinfection 

UV disinfection, or more specifically ultraviolet germicidal irradiation (UVGI), uses short-wavelength ultraviolet (UV-C) light to destroy microorganisms’ nucleic acids and disrupt their DNA. Unable to perform vital cellular functions, microorganisms are made inactive and/or die. 

• Ozone disinfection 

Ozone is a powerful oxidant and toxic to most waterborne organisms. Ozone disinfection, or ozonation, is an effective method to inactivate harmful protozoa and also works well against almost all other pathogens.

We go into more practical detail in the following comparison table, listing the advantages and disadvantages of each method while also noting how different treatments can be combined to achieve the necessary results.  

Further consideration: what type of bottle or can are you using? 

Different bottles or cans create other challenges for microbiological treatment, which you may need to consider. For example, unlike glass bottles, plastic bottles need continuous monitoring to ensure that there has not been too much UV energy interaction with the bottle.  Excessive UV can affect the plastic by giving it a chalky appearance and make the bottle brittle. Similarly, with ozone treatment, use of high ozone concentration levels with plastic polymers needs to be limited or the plastic can become sticky and too flexible. There is also risk of creation of by-product from the cap plastic material. With aluminum cans the interaction with UV and ozone also needs to be monitored to minimize off-taste.  

Achieving your ideal solution  

Clearly, achieving your ideal solution for microbiological water treatment will be specific to your processes, needs and the relevant regulations in the markets you are serving. With many years of experience in helping customers around the world optimize their bottled water quality, backed up by extensive technical know-how and a wide range of products and options, Sartorius can help in your investigation as well as support you once you are up and running. Here is a summary of how we support customers and help ensure protection throughout the production process. 

High-quality filtration 

Sartorius has specifically designed the Aquasart^® Membrane Filter family for water filtration treatment. The Aquasart^® range features a 0.2 µm PESU asymmetric membrane that is very robust and is a highly effective last barrier before the water is bottled and manufactured, being made with materials free of polyfluoroalkyl substances (PFAS).  

In addition, we recommend using Sartopure^® IND for the protection of the Aquasart^® filter cartridge upstream. Water tanks are protected from air pollution with Aerosart^® air filters using a sterile polytetrafluorethylene (PTFE) membrane.  

The cleaning protocol of all the equipment used during bottled water processes is also a key factor, as sterile water filtration is used for the external cleaning system of the  bottle-filler to avoid any water contamination of the bottles themselves.   

Quality control to minimize issues and avoid recalls 

To ensure quality along the production process, sampling can be implemented using an aseptic sampling system such as Takeone^®. The system offers multiple sampling number options as well as different configurations to hold the samples i.e., tubs, bottles, or bags.  

Samples obtained from different points in the production line then go to Quality Control. Some samples are used for chemical assays such as HPLC or wet chemistry assays. Here, the Claristep^® product line is ideal for multiple HPLC sample preps while a 0.2µm Minisart^® syringe filter can also be used.  When setting up, a Cubis^® II balance with an Arium^® Pro assures accurate measurement and Type 1,2,3 water based upon the method requirements. 

When testing for a range of spoilage microorganisms, the microbiology lab can use Nutrient Pad Sets  depending on local regulations, consisting of a microbiology membrane, petri dish and absorbent pad impregnated with a wide range of microbiology media. The media are stable at room temperature for 2 years, so no refrigeration is needed. All of which means the microbiology lab can be as efficient as possible while constantly maintaining the integrity of all the different assays being executed. 

A total solution for water quality  

The above chart shows a typical process with the different QC checkpoints along the way. Starting at the source, it also illustrates the importance of quality control and effective water treatments before water even reaches the bottling plant, as well as during washing and cleaning of equipment. These steps are covered in more detail in the previous article, but it bears repeating that the ideal solution for water quality will need to address the entire process. But rest assured, Sartorius has the knowledge and the products to help you throughout.  

Regulatory considerations 

The regulations for performing water quality control differ depending upon several factors: 

• Physical location of the production site – national and local regulations will apply. 

• Intended market – if the bottled water is sold to a different country/region, there may be other testing requirements. 

• Final configuration of the water – purified water is regulated differently from spring water. Mineralized and carbonated water is also regulated differently regardless of the water being purified or from spring. 

For example, in the United States the US FDA is responsible for regulating all bottled water. However, it will defer to the US EPA responsible for drinking water standards if the water is “purified” or spring derived. Then, if the water undergoes a carbonation process, the regulations for soft drinks apply and these differ from plain bottled water regulations. 

Regulatory resources 

USA:  

Drinking water standards and regulations 

• US FDA mandate 

Europe:  

Drinking water standards 

• DIRECTIVE (EU) 2020/2184 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 2020 on the quality of water intended for human consumption 

Natural mineral water 

• Directive 2009/54/EC on the exploitation and marketing of natural mineral waters 

Spring water 

• Regulated partly by Directive 2009/54/EC on the exploitation and marketing of natural mineral waters 

• Directive 98/83/EC on the quality of water intended for human consumption. 

Bottled drinking water 

• Directive 98/83/EC relating to the quality of water intended for human consumption. 

Worldwide 

WHO - Guidelines for drinking-water quality 21 March 202 

To discuss effective, high-quality microbiological water treatments in more detail and how to best implement them in your processes, please do not hesitate to get in touch. 

Read more about Sartorius solutions for water quality by visiting our dedicated water filtration page and resources.