What PT12 Covers
PT12 slimicides are biocidal products regulated under the UK GB BPR for the prevention and control of slime growth on materials, equipment, and structures in industrial processes. They are used in paper mills, manufacturing water circuits, and process water systems.
PT12 chlorine dioxide is used to break down existing biofilm and slime and to maintain a residual that prevents regrowth on process surfaces and in water circuits.
PT12 is distinct from PT11. PT11 covers preservation of water or other liquids in cooling and processing systems (cooling towers, heat exchangers); PT12 covers control of slime on the materials, equipment and structures of an industrial process, such as paper machine circuits. The correct product type follows the purpose of the treatment, and a product must be compliant for the specific type used.
Chlorine dioxide's GB BPR status is specific to the precursor route and product type; the in-situ routes are existing active substances in the GB Review Programme administered by HSE, and ChloroKlean PT12 products are supplied for the Great Britain market under GB BPR transitional arrangements. Check the route and product type on HSE's GB active substances list. EU BPR, which applies in the EU and Northern Ireland, runs its own evaluation of chlorine dioxide by precursor route and product type; no EU or NI authorisation or coverage is claimed on this page.
Key Applications
Paper & Pulp Mills
Slime control in paper machine water circuits, headboxes, and pulp processing systems.
Industrial Water Circuits
Biofilm and slime prevention in process tanks, spray systems, and pipework.
Manufacturing Processes
Control of biofouling on process equipment and structures to maintain efficiency.
Process Water Treatment
Ongoing treatment of recirculating process water to prevent slime and fouling.
Why Chlorine Dioxide for PT12?
Chlorine dioxide is well suited to slime control because it breaks down established biofilm, works across a wide pH range, and helps keep process water systems running efficiently.
Breaks Down Established Slime
Penetrates and destroys existing biofilm and slime structures on process surfaces.
Slime-Forming Bacteria Control
Effective against slime-forming bacteria, fungi, and algae in industrial water.
Wide pH Range
Maintains efficacy across pH 4-10, suited to variable process water chemistry.
Improves Process Efficiency
Reduces fouling and deposits that impair production and increase downtime.
Reduces Equipment Fouling
Keeps spray systems, tanks, and pipework clear, lowering maintenance requirements.
BPR Compliant
Supplied under GB BPR for PT12 slimicide use in Great Britain; EU/NI status is separate.
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 slime control | 0.1-0.5 mg/L ClO₂ residual in process water | BPR PT12 |
| Slug / shock dosing | Elevated periodic dose to clear established slime | BPR PT12 |
| Paper mill water circuits | Dose to a measurable residual across the circuit | BPR PT12 |
| Spray & tank systems | Dose per system volume and load per product guidance | BPR PT12 |
Slimicide dosing depends on process water chemistry, organic load, and circuit design. Always confirm site-specific dosing and monitoring with a competent water treatment adviser.
BPR Compliance
All ChloroKlean PT12 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 PT12 Slime Control Solutions?
Contact our team for PT12 chlorine dioxide slimicide recommendations and dosing guidance for your paper mill, manufacturing, or process water application.