Piping Material Selection for Reducing Legionella Risk and Biofilm
See the below chart for information on construction considerations and ratings for different pipe materials for Legionella control. The below chart’s information was referenced from the ASPE bulletin 1234.
| Pipe Material | Biofilm Growth Potential | Disinfectant Compatibility Issues | Water Temperature Limits | Other Construction Concerns |
| Copper | Biofilm Growth Potential:Starts low, becomes high as piping oxidizes | Disinfectant Compatibility Issues:Not compatible with chlorine/chloramines or other oxidizing disinfectants | Water Temperature Limits:82.2°C(180°F). Velocity must be slowed as temperature increases. | Other Construction Concerns:N/A |
| Carbonized Steel | Biofilm Growth Potential: High | Disinfectant Compatibility Issues: Not compatible with chlorine/chloramines or other oxidizing disinfectants | Water Temperature Limits: 82.2°C(180°F). Velocity must be slowed as temperature increases. | Other Construction Concerns: N/A |
| Stainless Steel | Biofilm Growth Potential: Low | Disinfectant Compatibility Issues: N/A | Water Temperature Limits: 82.2°C(180°F) | Other Construction Concerns: N/A |
| PPR | Biofilm Growth Potential: Medium | Disinfectant Compatibility Issues: Not compatible with chlorine/chloramines over 4ppm at 60°C(140°F). Not compatible with copper-silver ionization. | Water Temperature Limits: 60°C(140°F) | Other Construction Concerns: Issues can occur when there are elevated levels of copper in the water. |
| PEX | Biofilm Growth Potential: High | Disinfectant Compatibility Issues: Not compatible with chlorine/chloramines over 4ppm at 60°C(140°F). Not compatible with copper-silver ionization. | Water Temperature Limits: 60°C(140°F) | Other Construction Concerns: N/A |
| CPVC | Biofilm Growth Potential: Low | Disinfectant Compatibility Issues: N/A | Water Temperature Limits: 93.3°C(200°F), but piping pressure rating decreases as temperature increases. | Other Construction Concerns: Care must be taken during construction and occupation to not intermix incompatible materials with CPVC piping. |
Piping selection for water treatments systems is complex and has direct impact on biofilm growth, which leads to Legionella and other waterborne pathogen growth. Contact the experts at Legionella Control Systems for a risk assessment, Legionella testing, remediation, or a water management plan.
