Disinfection of a pharmaceutical water treatment system is an important step to consider when developing or acquiring your new system. There are several types of disinfection and whether it is chemical, physical or physico-chemical, the type of disinfection chosen will have an impact on the cost of capital and operation of your system as well as on its performance.

Although this information is valid for other sectors that require the production of ultra-pure water, this article discusses disinfection from a pharmaceutical perspective. In short, regardless of the sector of activity, the choice of disinfection system should not be overlooked. In this article, we will look at the advantages and disadvantages of chemical, thermal and ozone disinfection systems. Before we start, here are some of the reasons why it is important to opt for a good disinfection system in the pharmaceutical sector.


Why it is important to effectively disinfect a pharmaceutical water treatment system

First and most importantly, disinfection of a water purification system is the deactivation or destruction of microorganisms that may be found on the surfaces of your system, in the water present, or wherever the water comes in contact. The standards for disinfection in the pharmaceutical industry are all pre-established by the organizations that manage the industry. In fact, all pharmaceutical water purification systems must pass compliance tests in accordance with the various organizations. These tests, better known as SOP, are standards operating procedures that must be met in order to be qualified to supply pharmaceutical water.

These SOPs ensure consistent water quality to avoid problems in the production of water for parenteral injection or any other type of water for pharmaceutical use. Therefore, in order to ensure the consistency of operation and functioning of your system, as well as the achievement of the standards operating procedures, it is essential to choose the right type of disinfection for your system.

In other words, the choice of your disinfection technique must be based on the contaminants present, the type of water treatment used and your operational constraints. When the right technology is chosen, you will avoid problems related to government standards, the formation of biofilm that can cause problems for your system and bacterial recontamination of treated water.


Chemical disinfection

In the pharmaceutical industry, this is the most common type of disinfection. Chemical disinfection is most often done with peroxide or chlorine. Although they are the most used, peroxide and chlorine are not the only disinfectants used in the pharmaceutical industry. The choice of disinfectant should be based on the contaminants that may be present in the water and many other factors. For more details, the United States Pharmacopeia addresses the subject in the following article: USP- [1072].

However, no matter which product is chosen, the disinfection process remains essentially the same. To effectively perform the system disinfection process, the selected product must be added to the interior of the system so that it contacts all internal parts of the system. After the disinfectant solution has been exposed to all internal parts of the system for a pre-determined period of time, the system must be rinsed to remove all traces of the chemical.

As mentioned above, this technique is the most widespread in the pharmaceutical sector since it is relatively simple, inexpensive to acquire and very efficient. On the other hand, the operational costs are relatively high for the following reasons:

  • Constant purchase of chemicals
  • System must be shut down during disinfection
  • A lot of handling is required and therefore labor is required
  • Water used for disinfection must be rejected

Besides a high OPEX, chemical disinfection is often difficult to rinse properly, which can create downstream problems. Furthermore, automation of the chemical disinfection process is very difficult since it is difficult to measure when the process is complete. Finally, as mentioned above, this disinfection technique uses a large amount of water that must be discharged afterwards. As water is an important resource, many companies are becoming more and more concerned about it and are trying to minimize their use.

Thermal disinfection

You've probably already received a boiling water advisory from the city where you live, if not, you're lucky! In the same way as a boil water advisory, thermal disinfection is accomplished by increasing the temperature of the water quite significantly. Obviously, in the case of a local boil advisory, it is for drinking water. In the case of pharmaceutical use, thermal disinfection is intended to disinfect the entire system to ensure the production of pure, contamination-free water.

Quite simple as a principle and very easy to operate, thermal disinfection is done by raising the internal temperature of the water purification system to at least 85°C for approximately one hour.

The initial costs (CAPEX) for a heat disinfection system are high since this type of equipment requires substantial additions. These include insulation on all parts of the system and all other safety measures such as LOTO (lockout). These additions are essential to ensure the safety of the system operators. On the other hand, the energy costs (OPEX) are very low since all that is required is to heat the water to the right temperature when disinfection is to be performed and that's it. Although energy costs are low, the disinfection process is quite slow, especially if the heating system is electric.

Ozone disinfection

Ozonation is one of the most effective disinfection techniques. Ozone is an extremely powerful oxidizing gas and is highly volatile, which is why it must be generated on site with the help of an ozone generator such as the Ozonia series from SUEZ.

Probably the most expensive type of disinfection to purchase (CAPEX), ozonation is expensive because the price of ozone generators is very high. However, ozonation offers a very low OPEX. In addition to the price of the ozonators, several other factors make the initial costs for an ozone system high, such as the addition of a UV disinfection step to destroy excess ozone that may be present in the water.

As a disinfectant for a pharmaceutical system, ozone has many advantages. Among them, its low risk of causing injuries or accidents is not negligible. The reduction of these risks is caused, among other things, by the absence of chemical handling.

In addition, the ozonation process is very fast compared to other types of disinfection and does not require any workforce since the systems are automated. Because ozone can be irradiated by a downstream UV system, ozonation does not reduce or stop production and does not waste water.

Finally, ozone is very effective against total organic carbons (TOC) in water. As an aside, the TOC concentration in water is directly related to the organic matter concentration. This means that a decrease in TOCs ensures that the risk of pathogen levels is minimized. However, to ensure an efficient and optimal treatment, it is important to validate the necessary ozone concentrations since it can be complex to identify the needs and an overdose of ozone can cause premature wear on your equipment. Moreover, one of the problems of ozone disinfection is caused by its strong oxidizing power. It is quite common to have difficulty calibrating the various sensors in the system since they corrode at an accelerated rate.

Disinfection at the heart of your system

In order to reach the standards operating procedures, the choice of a disinfection technology must be made taking into account all the factors that can affect it. The optimization of your water purification system is intimately linked to the efficiency of all its stages, including the disinfection stage.

Although there are many other types of disinfection technologies, the three we have presented are among the most common in the pharmaceutical industry. In summary, the important thing to remember is that there are experts in the field who can help you identify which technology is best for your situation.

By then, we hope to have answered your questions about these three types of pharmaceutical disinfection. In the event that you are missing information or have additional questions, please do not hesitate to write to us or leave a comment and we will be happy to respond.