What PT11 Covers
PT11 products are biocidal preservatives authorised under the UK GB BPR for liquid-cooling and processing systems. They prevent microbial growth in cooling towers, HVAC systems, and industrial cooling circuits - critical for Legionella control under HSG274 Part 1.
PT11 chlorine dioxide is used both for shock dosing to bring systems under control and for continuous dosing to maintain a protective residual and prevent biofouling.
Key Applications
Cooling Towers
Legionella and biofilm control in open and closed recirculating cooling tower systems.
HVAC Systems
Microbial control in building HVAC and comfort cooling circuits.
Industrial Cooling Circuits
Process cooling, heat exchangers, and closed-loop systems that require biofouling control.
Chiller & Closed-Loop Systems
Preservation of chiller and closed-loop systems to maintain heat transfer efficiency.
Why Chlorine Dioxide for PT11?
Chlorine dioxide is a leading cooling water biocide because it controls Legionella and biofilm, works across a wide pH range, and helps maintain system efficiency.
Proven Legionella Control
Highly effective against Legionella in cooling systems, supporting HSG274 Part 1 compliance.
Superior Biofilm Control
Penetrates and breaks down biofilm on heat transfer surfaces where chlorine struggles.
Wide pH Range
Maintains efficacy across pH 4-10, well suited to alkaline cooling water.
Maintains Efficiency
Controls biofouling and slime that reduce heat transfer and increase energy use.
Algae Control
Effective against algae and slime-forming bacteria in open cooling systems.
BPR Compliant
Fully compliant with UK GB BPR for PT11 cooling system preservation.
Dosing & Compliance Notes
Typical chlorine dioxide (ClO₂) dose and residual figures below are indicative starting points. Always confirm site-specific dosing with a competent water treatment adviser.
| Application | Typical ClO₂ dose / residual | Key standard |
|---|---|---|
| Continuous residual dosing | 0.1-0.5 mg/L ClO₂ residual in the recirculating water | HSE HSG274 Part 1 |
| Shock / offline disinfection | Elevated dose to control biofilm, then return to residual | HSE HSG274 Part 1 |
| Legionella risk control | Dose to maintain residual with regular monitoring | HSE ACOP L8 |
| Closed-loop preservation | Dose per system volume and load per product guidance | BPR PT11 |
Cooling water dosing depends on system volume, load, and water quality. Always confirm site-specific dosing and monitoring with a competent water treatment adviser under HSG274.
BPR Compliance
All ChloroKlean PT11 products comply with UK GB BPR and EU Biocidal Products Regulation requirements. Safety data sheets and technical data sheets are available on request for every product.
Related Resources
Frequently Asked Questions
Need PT11 Cooling Water Solutions?
Contact our team for PT11 chlorine dioxide product recommendations and dosing guidance for your cooling tower, HVAC, or industrial cooling application.