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BioTherm BP8 Physical Properties


1.02 - 1.15 g/cm³ depending on inhibitors


7.5 - 10.5 depending on inhibitors

Boiling Point:



a clear, slightly viscous liquid. It is mildly sweet to the taste and has a non-pungent but characteristic aroma.

Available in:

5, 10, 15, 20, 25, 205 & 1000 litre containers and bulk tankers.


For a quote or assistance

Tel: +44 (0) 1792 586800

Non-Toxic Heat Transfer Fluid with Antifreeze Function. Based on Propylene Glycol and BS6580 & ASTM D1384 High Temperature Corrosion Inhibitors for Biomass Heating Systems.

BioTherm BP8 has been especially formulated for use as a Non-Toxic heat transfer fluid in Biomass Heating Systems.

Antifreeze AntiFreeze

BioTherm BP8 is miscible with water in all proportions and can protect Geothermal and Air Source systems down to -50°C depending on concentration.

non toxic Non-Toxic

BioTherm BP8 has an LD50 toxicity rating (Oral Rat) of ≥15,000 mg/kg of body weight (bw) = “Relatively Harmless”. As confirmed by the Hodge & Sterner Scale. 

Optimum Flow Optimum Flow

BioTherm BP8 has improved heat transfer characteristics, including lower Dynamic Viscosity and higher Thermal Conductivity. For detailed comparison please refer to the Fluid Performance Chart - available upon request.

Corrosion control Corrosion Control

BioTherm BP8 contains synergistic corrosion inhibitors to protect metals commonly found in such systems. It has been tested in accordance with BS5117 and found to meet BS6580 and ASTM D1384 corrosion standards.

Biodegradable Biodegradable

BioTherm BP8 mixtures are readily biodegradable (90% over ten days) and will not remain in the environment or bio-accumulate.

Quality Assured Quality Assured

All Hydratech products are manufactured in accordance with certified ISO9001-2008 procedures


As per BSRIA guide BG 29/2012 all pipe-work systems should be clean and free from biological contamination and debris prior to commissioning.

To minimise corrosion air ingress should be minimized. A pressurised system is best.

Determine the total system volume and add BioTherm BP8 to the system according to the minimum operating temperature required (see table). The minimum dose of BioTherm BP8 should not be less than 25% of the system volume and the maximum does not normally exceed 60%. We recommend the use of deionised, distilled or UltraPure™ water for this dilution. Avoid water containing high levels of calcium salts or Chlorides [Cl-].

Health & Safety: Please refer to the associated Safety Data Sheet - available via Login or upon request.

Shelf Life: 3 years when stored in sealed containers out of direct sunlight.

Available in: 5, 10, 15, 20, 25, 205 & 1000 litre containers and bulk tankers.

BioTherm BP8 can also be supplied as a Ready-To-Use solution.

Mixing Guide

Frost Protection °C v/v of BioTherm BP8 Refractive Index
-10 25% 1.356
-15 33% 1.364
-20 39% 1.370
-25 44% 1.373
-30 48.5% 1.380
-35 52.5% 1.383

When measuring the percentage of BioTherm BP8 in the system use a refractometer

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