What PT5 Covers
PT5 disinfectants are biocidal products regulated under the UK GB BPR for drinking water disinfection. They are used to treat potable water systems, building water supplies, and distribution networks to control Legionella, biofilm, and other waterborne pathogens.
PT5 chlorine dioxide is used for continuous disinfection of hot and cold water systems and for maintaining a protective residual through building distribution pipework.
Key Applications
Potable Water Treatment
Disinfection of drinking water in municipal, private, and building water supplies.
Building Water Systems
Hot and cold water system treatment for hospitals, care homes, hotels, and offices.
Distribution Networks
Residual protection through distribution pipework to control biofilm and regrowth.
Legionella Control
Continuous or periodic dosing to control Legionella in water systems under ACOP L8.
Why Chlorine Dioxide for PT5?
Chlorine dioxide is a leading choice for drinking water because it controls Legionella and biofilm, maintains a stable residual, and does not form regulated chlorination byproducts.
Proven Legionella Efficacy
Highly effective against Legionella pneumophila in hot and cold water systems.
Superior Biofilm Control
Penetrates and destroys biofilm in pipework where Legionella and other bacteria persist.
No THM Formation
Does not produce trihalomethanes or the disinfection byproducts associated with chlorine.
Stable Residual
Maintains a lasting residual through distribution systems for continuous protection.
Wide pH Range
Maintains efficacy across pH 4-10, unlike chlorine which weakens above pH 7.5.
BPR Compliant
Fully compliant with UK GB BPR for PT5 drinking water disinfection.
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 |
|---|---|---|
| Potable water residual | Within the UK condition: ClO₂ + chlorite + chlorate combined ≤ 0.5 mg/L as ClO₂ in water entering supply | DWI conditions of use (Reg. 31) |
| Legionella control (hot & cold water) | Continuous dose to a measurable residual at outlets | HSE ACOP L8 / HSG274 |
| System disinfection (biofilm) | Elevated shock dose, then return to residual dosing | HSE HSG274 |
| Distribution network residual | Residual set by the site scheme; WHO provisional guideline values for chlorite and chlorate are 0.7 mg/L each | WHO GDWQ / DWI |
WHO does not set a guideline value for chlorine dioxide itself; its provisional guideline values are 0.7 mg/L for chlorite and 0.7 mg/L for chlorate. Separately, the UK Drinking Water Inspectorate requires the combined concentration of chlorine dioxide, chlorite and chlorate not to exceed 0.5 mg/L as chlorine dioxide in water entering public supply, and HSE HSG274 refers to the same combined figure for drinking water in building systems. Always confirm which conditions apply to your supply and confirm dosing and monitoring with a competent water treatment adviser.
BPR Compliance
All ChloroKlean PT5 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 PT5 Drinking Water Solutions?
Contact our team for PT5 chlorine dioxide product recommendations and dosing guidance for your potable water or building water system application.