PT11 Cooling Water

UK Stockholder

PT11 Chlorine Dioxide for Cooling Water Systems (UK)

PT11 covers preservatives used to control harmful organisms in open and closed liquid-cooling and processing systems; it does not establish suitability of every product for every circuit. ChloroKlean Plus L20 may be assessed where current label and technical documents support the intended use. Assess design, corrosion inhibitors, glycol, materials, operating conditions, dosing and monitoring. No routine recommendation is made for inhibited closed heating or chilled-water loops without expressly supported current instructions and written compatibility evidence. Assess an external evaporative spray-water circuit separately from the enclosed process loop. Products must be authorised or lawfully supplied under applicable GB BPR transitional arrangements.

ChloroKlean Plus L20 may be assessed for PT11 cooling-water preservation where current label and technical documentation support the intended use. Confirm the applicable GB BPR transitional supply position, system compatibility and permitted label before use; manage evaporative cooling towers through the complete HSG274 Part 1 programme.

What PT11 Covers

PT11 products are preservatives for open and closed liquid-cooling and processing systems. This legal scope is not blanket product suitability. An individual product must be authorised or lawfully available under applicable GB BPR transitional arrangements and used only for the purposes, users, methods and conditions on its permitted label.

PT11 is not blanket permission to disinfect all water, equipment or surfaces. Classification depends on the intended purpose. For evaporative cooling, biocide use is only one part of HSG274 Part 1 control alongside risk assessment, a written scheme, cleaning, inspection, maintenance, monitoring and corrective action.

Assess system design, existing corrosion inhibitors, glycol, materials, operating conditions, dosing and monitoring against current ChloroKlean Plus L20 label and technical documents. No routine recommendation is made for inhibited closed heating or chilled-water loops without expressly supported current instructions and written compatibility evidence. An external spray-water circuit in closed-circuit evaporative equipment must be assessed separately from its enclosed process loop.

Key Applications

Cooling Towers

Preservation uses covered by the exact product label, within the wider HSG274 Part 1 control programme.

Evaporative Spray-Water Circuits

Assess external spray water in closed-circuit evaporative equipment separately from the enclosed process loop, against current product instructions and HSG274 Part 1 controls.

Industrial Cooling Circuits

Assess process-cooling preservation against design, existing inhibitors, glycol, materials, operating conditions, system demand, discharge and current label and technical documents.

Inhibited Closed-Loop Assessment

No routine recommendation for inhibited closed heating or chilled-water loops without expressly supported current instructions and written compatibility evidence.

Evaluating Chlorine Dioxide for PT11

Chlorine dioxide is one oxidising-biocide option. Suitability and performance depend on the specific formulation, delivered concentration, contact time, demand, mixing, materials and operating conditions.

System-Specific Verification

Verify microbiological outcomes in the actual system; a product or residual alone does not establish HSG274 control.

Biofilm Evidence

Treat biofilm claims as formulation- and condition-specific, and confirm them with representative monitoring.

Water Chemistry

Assess pH alongside oxidant demand, temperature, contact time and interactions with the full treatment programme.

Operational Context

Track fouling and heat-transfer indicators rather than assuming an efficiency benefit from chemistry alone.

Defined Target Organisms

Use only for organisms and uses supported by the permitted label; published findings do not transfer automatically.

Lawful GB BPR Route Required

Check that the product is authorised or lawfully available under relevant GB BPR transitional arrangements and that its permitted label covers the intended PT11 preservation use.

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	Set only from the permitted label and site-specific written scheme	Product label and HSG274 Part 1 context
Compatibility assessment	Review existing corrosion inhibitors, glycol, materials and operating conditions before specifying treatment	Current product instructions and written compatibility evidence
Legionella risk control	One element of the risk assessment and written scheme, not proof of control	ACOP L8 and HSG274 Part 1
Inhibited closed heating / chilled-water loops	No routine recommendation without expressly supported current instructions and written compatibility evidence	PT11 scope alone does not establish product suitability

No universal dose is given here. Cooling-water dosing and monitoring depend on the lawfully supplied product, permitted purpose, system and written scheme. Use competent advice, the permitted label and Safety Data Sheet.

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

A PT11 preservative is a biocidal product for controlling harmful organisms in open and closed liquid-cooling and processing systems. This is a legal product-type scope, not blanket suitability for every circuit. In Great Britain, the product must be authorised or lawfully available under applicable GB BPR transitional arrangements and used as its permitted label allows.

PT11 concerns preservation purposes, not a blanket public-health claim. Where a product is lawfully supplied under the applicable GB BPR position and its permitted label covers the intended use, treatment can form one part of the written scheme. Performance must be verified and does not replace any ACOP L8 or HSG274 Part 1 control.

There is no universal dose. Use the permitted product label and a site-specific written scheme developed with competent advice. Do not derive a commercial dose from third-party studies or general web guidance.

It may support biofouling control where the lawfully supplied, permitted treatment is effective, but any heat-transfer or energy benefit must be measured in the actual system. It should not be assumed from the active substance alone.

No routine recommendation is made without expressly supported current product instructions and written compatibility evidence. Assess design, existing corrosion inhibitors, glycol, materials, operating conditions, dosing and monitoring. PT11 legally includes open and closed systems, but does not establish this product's suitability for any particular loop. Assess external spray water in closed-circuit evaporative equipment separately from the enclosed process loop.

Ask ChloroKlean for the current GB BPR transitional supply information, label, Safety Data Sheet and technical documents for ChloroKlean Plus L20. Assess the intended PT11 use, design, inhibitors, glycol, materials, operating conditions, dosing and monitoring before purchase or use. PT5 drinking-water products are not a substitute for a supported PT11 use.

Need PT11 Cooling Water Solutions?

Ask for current GB BPR status, permitted-label and technical information for your intended liquid-cooling or processing-system preservation use.