Across aerospace, automotive, electronics, medical devices, and precision engineering, achieving the required level of component cleanliness is essential to ensuring product performance, reliability, and compliance. A new generation of PFAS-free vapour degreasing solvents – led by formulations such as ProSolv®5408e and ProSolv®AS-1 demonstrates that environmental responsibility and uncompromising cleaning performance are no longer mutually exclusive.
Why Vapour Degreasing Endures
Vapour degreasing has been a cornerstone of industrial cleaning for decades, and for good reason. The process exploits the physics of phase change: a solvent is heated to boiling, generating a stable vapour zone in which cooler components are suspended. As vapour condenses on the part surface, it dissolves oils, greases, machining fluids, waxes, and particulate residues before draining away under gravity – leaving components clean, dry, and residue-free without any mechanical scrubbing.
The elegance of the process lies in its physics. Cleaning occurs in a closed loop – solvents are continuously distilled and recovered via cooling coils – making it both efficient and measurable. Cycle times are short, results are repeatable, and the absence of mechanical agitation means even the most delicate components emerge unscathed.
The Molecular Mechanics Behind Effective Cleaning
Understanding why modern solvents perform so well requires a look at the molecular properties that drive cleaning effectiveness. Several characteristics work in concert:
Low Surface Tension
A solvent that cannot wet a surface cannot clean it. Low surface tension allows the fluid to spread rapidly across complex geometries – penetrating micron-scale features, tight clearances, and blind holes that would defeat many conventional cleaning methods. This is particularly critical in sectors such as electronics assembly or medical device manufacture, where intricate topographies are the norm rather than the exception.
Solvency Strength and Polarity
Most industrial soils – oils, greases, machining fluids – are nonpolar and hydrophobic. Matching solvent polarity to contaminant type is fundamental to efficient cleaning. Low-polarity solvents dissolve these soils readily, and when paired with low surface tension, the combination delivers consistent removal even in hard-to-reach areas. Solvency strength is typically expressed as a Kauri-Butanol (Kb) Value; a higher figure indicates broader capability across a wider range of contaminants. The Solvation Mechanism
When a solvent molecule contacts a contaminant, it progressively surrounds and separates individual molecules or particles – weakening intermolecular forces until the soil detaches and is carried away. In a vapour degreasing system, this occurs continuously as fresh condensate flows across the component surface, ensuring dissolved soils are consistently drained rather than redeposited.
Next-generation, PFAS-free, high performance vapour degreasing solvent

Developed by EnviroTech Europe, ProSolv®5408e is engineered for critical cleaning applications where failure is not an option. It is a PFAS-free formulation with a Kb Value of 98 – placing it firmly in the high-solvency category – and a Global Warming Potential (GWP) of less than 1 (100-year Integrated Time Horizon, AR4). Zero Ozone Depletion Potential (ODP) completes a strong environmental credentials profile.
“With a Kb Value of 98 and a Global Warming Potential of less than 1, ProSolv®5408e demonstrates that high cleaning performance and low environmental impact can coexist in a single formulation.”
Its exceptionally low surface tension allows penetration into the finest features and most complex geometries, making it equally at home cleaning a multilayer PCB assembly and an aerospace turbine component. Parts exit the degreaser clean, dry, residue-free, with non-volatile residue below 10 ppm and with no additional drying required.
Operationally, the formulation is straightforward to manage. Its mid-range boiling point of approximately 46°C makes for safe and comfortable handling, while its stable chemistry eliminates the need for additives or routine test kits. It is non-flammable, carries no flash point, and is classified as non-hazardous for transport – a meaningful advantage for sites managing COSHH compliance or seeking to streamline their chemical safety burden.
ProSolv®5408e is also compatible with standard vapour degreasing equipment and supports ultrasonic-assisted cleaning, broadening its applicability further. High fluid density, combined with high solvency, means it performs reliably in both conventional and ultrasonic-assisted systems without modification.
ProSolv®5408e Features and Benefits
- Low hazard classification for improved operator safety and simplified transport.
- Sustainable PFAS-free formulation, RoHS compliant.
- Zero Ozone Depletion Potential (ODP).
- Global Warming Potential (GWP) of less than 1, AR4 100yr Integrated Time Horizon (ITH).
- High density solution, excellent for ultrasonic cleaning.
- Mid-range boiling point (46°C).
- High Solvency (Kb Value 98) for a variety of contaminants
- Non-flammable (no flash point).
ProSolv®5408e Testing
- Flash Point ASTM D3828 and ASTM D93.
- Flammable limits ASTM E918.
- Stock Loss ARP1755B.
- IGA Intergranular attack.
- Stress corrosion of titanium alloys ASTM F945-12.
- Hydrogen Embrittlement ASTM F519-17a.
ProSolv®5408e is available in the following container sizes and weights:
194 litre (approx.) drum, 243kg.
18 litre (approx.) can, 23kg.
The weight of ProSolv®5408e is 1.26 kg per litre.
PFAS-free, high performance precision cleaning solvent for highly sensitive components

ProSolv®AS-1 is a high-performance, sustainable PFAS-free precision cleaning solvent engineered for flushing applications, monosolvent and as a rinsing agent for co-solvent and bi-solvent applications. With controlled solvency strength, clean evaporation characteristics, and broad material compatibility, it delivers consistent removal of common contaminants for sensitive and delicate components.
ProSolv®AS-1 is an environmentally friendly, non-flammable vapour degreasing solvent cleaner, the perfect replacement for HFE, HFC and HCFC solvents. Designed for the cleaning of medium oils / fluxes or light cleaning work, with zero Ozone Depletion Potential (ODP) and a Global Warming Potential (GWP) of less than 1 (100-year Integrated Time Horizon, AR4).
ProSolv®AS-1 delivers moderate solvency suited to light-to-medium soil loads — effective without being aggressive on sensitive components . Its mid-to-high boiling point (54°C) ensures stable vapour phase performance, while clean evaporation and low residue characteristics make it well-suited to closed-loop solvent systems. Compatible with stainless steel, aluminium, copper, brass, and common engineering alloys. No adverse effects have been observed under normal operating conditions.
ProSolv®AS-1 Features and Benefits
- Sustainable PFAS-free formulation, RoHS compliant.
- Zero Ozone Depletion Potential (ODP).
- Global Warming Potential (GWP) of less than 1, AR4 100yr Integrated Time Horizon (ITH).
- Mid to high boiling point (54°C).
- Mid-range Solvency (Kb Value 44) for higher sensitivity components.
- Non-flammable (no flash point).
- Low hazard classification for improved operator safety and simplified transport.
ProSolv®AS-1 is available in the following container sizes and weights:
180 litre (approx.) drum, 250kg.
18 litre (approx.) can, 25kg.
The weight of ProSolv®AS-1 is 1.39 kg per litre.
Sectors and Applications
ProSolv®5408e and ProSolv®AS-1 are approved and in active use across a broad range of precision industries, including:
- Aerospace and Avionics – where stringent cleanliness standards and material compatibility requirements demand a proven, validated solvent chemistry.
- Electronics and Electrical – cleaning PCBs, connectors, and sub-assemblies to the fine residue tolerances that modern circuitry demands.
- Medical Device Manufacturing – where biocompatibility and traceability of cleaning processes are essential.
- Automotive and Motorsport – precision components, fuel system parts, and safety-critical assemblies.
- Military and Defence – meeting demanding cleanliness specifications for critical applications.
- Oxygen Cleaning – where residue-free surfaces are a safety imperative, not merely a quality target.
- Power Generation, Marine, and Railway sectors – for maintenance and precision component cleaning across harsh-environment applications.
Future-Ready Precision Cleaning
Choosing the right cleaning fluid is a highly strategic decision for any precision cleaning process. At EnviroTech Europe, we offer a wide portfolio of sustainable, high-performance solvents alongside the latest operator-friendly vapour degreasing equipment to meet the demanding requirements of modern precision cleaning applications. Our technical staff can offer advice on legislative changes which affect your industry.
Further information
ProSolv®5408e and ProSolv®AS-1 are manufactured in the United Kingdom and available globally through EnviroTech Europe’s distribution network, with short lead times. The EnviroTech technical team offers guidance on solvent selection, changeover procedures and equipment compatibility.
For more information, please visit: https://www.envirotech-europe.com/vapour-degreasing-solvents/ or telephone: +44 (0) 20 8942 9177.
Supplied and supported by

EnviroTech Europe Ltd, Steward House, 14 Commercial Way, Woking, Surrey GU21 6ET, United Kingdon
Tel +44 (0) 20 8942 9177 | www.envirotech-europe.com | [email protected]
Company registered in England and Wales No. 4170693





