Chlorine Dioxide Impact on Plumbing Materials for Legionella Control
Chlorine dioxide (ClO₂) is a powerful disinfectant that can effectively combat bacteria like Legionella in water systems. However, chlorine dioxide comes with challenges in its interaction with certain plumbing materials.
Aggressive Impact on Copper and Plastics
One of the primary concerns is chlorine dioxide’s impact on copper piping and plastic materials like PEX, PE-RT, PP-R, and PP-RCT. Some research has shown that chlorine dioxide is significantly more aggressive towards these materials than free chlorine or chloramines, even when used in lower concentrations.
This is because chlorine dioxide has a different attack mechanism compared to other disinfectants. It can cause oxidative damage, leading to surface degradation and reduced material longevity. Studies have shown that copper and many plastic piping systems exposed to chlorine dioxide may experience premature aging, cracking, and other forms of deterioration. For these materials, regular exposure to chlorine dioxide could result in reduced service life, making them less suitable for long-term use in systems where chlorine dioxide is consistently present.
CPVC and Temperature Stability
On the other hand, CPVC (chlorinated polyvinyl chloride) shows notable resistance to chlorine dioxide. According to the Plastics Pipe Institute (PPI), CPVC remains stable in environments where water temperatures are 200°F or lower, making it a viable option for hot and cold water distribution systems utilizing chlorine dioxide for Legionella remediation or as part of an ongoing Legionella water management program. CPVC’s resilience at elevated temperatures and its compatibility with chlorine dioxide make it a better choice in facilities where Legionella control is necessary but material durability cannot be compromised.
Applications in Legionella Control
Chlorine dioxide’s common use in controlling Legionella is in large-scale facilities such as hospitals, nursing homes, and hotels – larger buildings that have a higher Legionella risk and potential Legionella liability. Legionella thrives in water temperatures between 68°F and 122°F and poses significant health risks, particularly in these complex water systems. Chlorine dioxide generators can be added to these plumbing systems to inject controlled amounts of disinfectant, targeting Legionella in both hot and cold water lines. While this approach is effective in reducing Legionella threats, the choice of piping material becomes critical to prevent degradation over time.
Choosing the Right Piping Material with Legionella in Mind
Given the varied effects of chlorine dioxide on different materials, it’s essential for building specifiers, designers, and facility managers to carefully evaluate piping systems when considering chlorine dioxide for Legionella control. The type of piping material, water temperature, and disinfectant concentration all play a role in determining the longevity and effectiveness of a plumbing system.
For facilities using chlorine dioxide for Legionella control, CPVC appears to be a reliable option, particularly in applications where water temperatures are 200°F or below. On the other hand, copper and certain plastic piping systems may require more frequent maintenance or replacement due to chlorine dioxide’s aggressive nature.
Contact an Expert
If you are considering chlorine dioxide for Legionella control, it is crucial to select piping materials that can withstand its oxidative properties. Contact Legionella Control Systems so we can work with you to help ensure that your plumbing systems remain functional and safe over the long term and that you are effectively controlling Legionella. We can also explore other options that may be more suitable for your facility including copper-silver ionization, mixed oxidants, monochloramines, and other effective Legionella control mechanisms including point-of-use filters.
