3M™ Novec™ 73DE Replacement

As the clock runs out on the 3M™ Novec™ phaseout, many manufacturers are wondering how to switch their vapor degreasers to a 3M™ Novec™ replacement solvent such as BestSolv® Engineered Fluids.

Here are the steps to use when converting your vapor degreaser to a new solvent.

Remove Old Solvent

Completely remove the old solvent from the vapor degreaser before adding the new solvent. Any residual old solvent left in the lines may be flushed with the new solvent. Do NOT use water to clean the vapor degreaser or flush the lines. If residual old solvent remains or has turned acid previously, neutralize the degreaser and all surfaces.

Add New Solvent

Review the Safety Data Sheet for the new solvent prior to first use. As always when handling solvents, use appropriate protective equipment as mentioned in the Safety Data Sheet. Since most solvents are designed to evaporate quickly, be careful not to leave the solvent container open any longer than necessary.

Identify Boiling Point of New Solvent

The boiling point on your new solvent may be different from that of the old solvent. Vapor degreaser settings are based on the boiling point of the solvent used, and should be adjusted when a new solvent is used in the degreaser.

Use the Safety Data Sheet, Technical Data Sheet, or other publicly available source to identify the boiling point of the new solvent. For BestSolv® Engineered Fluids, you can find this information through our Technical Data Sheets page.

Adjust Vapor Degreaser Settings

Use the new solvent’s boiling point as a reference for changing the following settings on your vapor degreaser:

For example, a solvent with a boiling point of 165 °F would have a Vapor Up Control (TH-1) set point of 155 °F (165 – 10 = 155).

That’s it! Your vapor degreaser is ready to return to precision cleaning with your new solvent.

NOTE: Vapor degreaser controls differ by manufacturer. Some may not contain all of the settings described.

For further information about vapor degreaser settings, see the reference section below.

Vapor Degreaser Settings Reference

• Liquid Temperature Control (LTC): Set 7-10 °F above the boiling point of the solvent being used. A 10 °F rise in the boiling point indicates that the boiling sump has accumulated the equivalent oil solution of approximately 30% by weight, along with any other contaminants. Boil down and addition of fresh solvent is recommended.
• High Temperature Control (HTC): Set 10-15 °F above the boiling point of the solvent being used. A 10 °F rise in the boiling point indicates that the boiling sump has accumulated the equivalent oil solution of approximately 30% by weight, along with any other contaminants. Continued operation may be hazardous.
• Low Level Control (LLC): A safety to turn the heat off if the liquid level falls below a safe level.
• Refrigeration Control (RT): Regulates the temperature of the cooling coils. Typically set at 45-50 °F. It is not necessary to change this setting when changing solvents.
• Solvent Vapor Control (SVC): Turns off the heat in the event of high vapor level and must be set at 10 °F below the boiling point of the solvent being used.
• Vapor Up Control (TH-1): Turns on an indicator light when the solvent vapors are up to proper level on the cooling coils. This indicates the equipment is ready to operate. It also inhibits the spray pump(s) when the vapor line is below the normal operating level. The proper temperature setting is 10 °F below the boiling point of the solvent being used.

PFAS chemicals, or per- and polyfluoroalkyl substances, are a group of man-made chemicals characterized by a chain of carbon atoms bonded to fluorine atoms. These substances can be highly persistent in the environment, and some do not break down easily, earning them the nickname “forever chemicals.” Not all chemicals that are now classified as PFAS chemicals remain in the environment for a long time. The newer generations do break down.

PFAS chemicals have been widely used since the 1940s, and are valued for their ability to repel water and oil. PFAS chemicals are essential for the production of many products that are significant to modern society, such as semiconductors, mobile devices and aircraft.

An azeotrope is a mixture of two or more liquids that maintains a constant boiling point and composition throughout the distillation process. This means the proportion of each chemical remains constant, regardless of temperature changes. An azeotropic mixture behaves as a single substance, making it invaluable in various industrial applications.

If you are asking what is an azeotrope, the simplest way to understand it is this: instead of separating into different components as it boils, the mixture stays stable and evaporates as though it were one fluid. That stability is what makes azeotropes especially useful in processes where consistent performance matters.

Understanding what is an azeotrope is particularly important in vapor degreasing and precision cleaning. Because the mixture remains uniform during use and recovery, it helps maintain cleaning consistency over time. This can support more predictable results, reduce process variation, and improve solvent management in demanding manufacturing environments.

Another reason what is an azeotrope matters is that azeotropic formulations are often designed to combine the strengths of different components while minimizing some of their individual limitations. In practical terms, that can mean better cleaning performance, more stable operation, and more efficient reuse through distillation.

So, what is an azeotrope in an industrial setting? It is a specially balanced solvent mixture that delivers stable composition and consistent behavior during boiling and reuse, which is exactly why it is so important in applications like vapor degreasing.

For more information on why azeotropes matter for vapor degreasing, see our page What is an Azeotrope and Why is it Important for Vapor Degreasing?

Manufacturers replacing 3M™ Novec™ or methylene chloride have three main options:

• Drop-in replacements – Engineered fluids that are molecularly identical to Novec™ solvents, allowing processes to continue with little or no revalidation.
• Similar molecule blends – Use a different molecule than 3M™ Novec™ but offer similar properties, at a lower price point.
• PFAS-free alternatives – New solvent formulations that provide strong cleaning performance while meeting the strictest regulatory standards domestically and worldwide.

BestSolv® Engineered Fluids cover each of these categories, helping manufacturers maintain continuity today while preparing for long-term compliance.

Our role goes beyond supplying solvent choices. We guide you through revalidation and material compatibility so you can move forward with confidence. We know how critical process continuity is in mission-driven industries, and we are committed to being a trusted technical partner in your transition.

While vapor degreasing solvents are compatible with metals, plastics and elastomers can react differently. Some may show changes such as surface stress, brittleness, or swelling, depending on the material. Because performance varies, it’s best to test any new solvent with your specific plastics and elastomers to confirm compatibility. Reach out today to one of our Chemical Team members for detailed compatibility information.

Safety and compliance are top priorities when selecting a vapor degreasing solvent. Here are the key considerations:

• Worker Safety: Some legacy solvents, such as methylene chloride and trichloroethylene (TCE), carry significant health hazards and are subject to strict workplace exposure limits. Modern options like BestSolv® Engineered Fluids are nonflammable and designed with lower toxicity profiles to help reduce operator risk.
• Environmental Regulations: With ongoing updates to EPA and EU REACH standards, including measures to reduce high-GWP and PFAS-containing solvents, the need for compliant alternatives grows. BestSolv® fluids, including PFAS-free options, are formulated to align with these evolving regulations while maintaining strong cleaning performance.
• Process Compliance: Aerospace, medical device, and electronics industries require solvents that can pass audits and validation testing. BestSolv® fluids support validated processes.
• Sustainability & Emissions Control: Modern degreasing fluids and solvents are designed for closed-loop recovery systems, minimizing emissions and solvent loss, which reduces both environmental impact and operating costs.

For detailed information on handling, exposure limits, and other safety measures for BestSolv® fluids, please refer to the Safety Data Sheet (SDS) for each fluid.

Selecting a solvent is not just about performance today—it’s about ensuring reliability and supply continuity for years to come. Here are the key factors to consider:

• Supply Chain Stability: Many companies single-sourced their legacy 3M™ Novec™ fluids, creating major vulnerabilities when supply ended. BestSolv® fluids are dual-sourced, giving manufacturers consistent, reliable access to the solvents they need without the risk of disruption. 

• Validation Requirements: Aerospace, medical device, and electronics industries demand extensive revalidation when switching chemistries. BestSolv® offers exact molecular replacements (minimizing requalification), as well as cost-effective similar molecule fluids and PFAS-free fluid options as sustainable alternatives. 

• Performance & Compatibility: The right solvent must deliver effective cleaning, material compatibility, and process efficiency. Our team partners with you to review your soils, materials, and equipment, helping ensure your solvent choice is well-suited for both current and future needs.

At Best Technology, we help you look beyond the immediate change to make a solvent choice that protects your operations and delivers confidence in the long term.

BestSolv® Engineered Fluids do not turn acidic on their own because they contain no water. If your solvent appears cloudy, discolored, or shows unusual behavior, it usually indicates that water or contaminants, such as particulates or metal shavings, are entering the vapor degreaser from an external source.

• Test the pH of the solvent

• Common Contamination Intrusion:
  • Water-based oils or fluids
  • Coil condensation Temperature
  • Cooling system leaks
  • Water Separator Issues
  • Metal particulate build-up in the tank

If your vapor degreaser becomes acidic, address it promptly to prevent corrosion of joints, welds, and other components.

At Best Technology, we help customers troubleshoot issues like this to maintain solvent integrity, process reliability, and audit readiness. If you suspect contamination, our team can walk you through step-by-step checks or recommend further testing to keep your system running safely and efficiently.

No, stabilizers are not required with BestSolv® Engineered Fluids. This is one of their advantages over older solvents such as trichloroethylene (TCE), which often needed stabilizer boosters to prevent acid breakdown.

BestSolv® Engineered Fluids are chemically stable, nonflammable, and water-free. Because they do not absorb or attract water, they resist acid formation under normal operating conditions.

By maintaining equipment properly and keeping water out of the system, BestSolv® solvents remain stable and effective without the need for stabilizer additives.

At Best Technology, our goal is to help customers achieve safe, reliable, and low-maintenance vapor degreasing. If you ever suspect solvent instability, our team can walk you through a step-by-step check to confirm and correct the root cause.

Cleanliness validation is essential in industries where performance and safety depend on residue-free parts. Here are the most common methods:

• Gravimetric Testing: Weighing parts before and after cleaning to measure the total nonvolatile residue (NVR) left behind.
• FTIR Analysis: Using infrared spectroscopy to detect organic residues at trace levels.
• Water Break Test: Ensuring no hydrophobic films remain by checking how water sheets or beads on a surface.
• Dyne Testing: Measuring surface energy to confirm readiness for coatings, adhesives, or bonding.
• SIR (Surface Insulation Resistance): Common in electronics to confirm that no ionic residues remain that could lead to conductivity issues.

BestSolv® Engineered Fluids are designed for high solvency and fast drying, making them ideal for meeting these validation standards.

At Best Technology, we don’t just supply the solvent — we work with you to ensure your parts consistently meet the standards required for aerospace, medical device, and electronics manufacturing.

Complex part geometries can trap solvent, leading to spotting, residues, or longer cycle times. To improve drying and ensure parts are ready for use, consider these adjustments:

• Part Orientation: Angle parts to encourage solvent drainage from blind holes, threads, or capillaries. Vertical orientation often allows vapors and condensate to escape more efficiently.
• Basket & Fixture Design: Use open, perforated fixtures that allow free vapor circulation. Avoid designs that trap liquid in pockets or shield vapor flow.
• Withdrawal Speed: Raise parts slowly through the vapor zone so condensation has time to evaporate, minimizing solvent retention and spotting.
• Ultrasonics & Agitation: Gentle ultrasonics or controlled agitation help release solvent and contaminants from intricate features.
• Secondary Drying Aids: Warm nitrogen blow-off, vacuum drying, or extended dwell time above the vapor line can be used for especially challenging geometries.

BestSolv® Engineered Fluids are formulated with low surface tension and high volatility, allowing them to wick into—and then quickly evaporate from—tight spaces.

At Best Technology, we work with you to evaluate part design and solvent choice so your process delivers clean, dry, and validation-ready parts, even for the most complex assemblies.

Minimizing solvent consumption lowers operating costs and reduces environmental impact. Key strategies include:

• Modern Equipment Design: New vapor degreasers use secondary cooling coils, freeboard extensions, and sliding covers to capture vapors and cut solvent loss.

• Closed-Loop Recovery: Many systems are engineered for continuous solvent distillation and recycling, reducing waste and keeping emissions low.

• Optimized Loading Practices: Proper basket design and avoiding fast motion of parts when transferring loads reduces drag-out and improves efficiency.

• Reduce or Eliminate Air Flows: Air movement such as HVAC returns, draft hoods and air vents can act like a chimney, pulling solvent vapors out of the degreaser.

• Maintenance & Monitoring: Regular checks of seals and gaskets help maintain efficiency and extend fluid life.

To learn more about reducing solvent loss, see our page How to Minimize Solvent Losses from Vapor Degreasers.

At Best Technology, we not only supply fluids but also help you optimize equipment, processes, and solvent choice to achieve the lowest possible emissions without sacrificing cleaning performance.

The environmental advantage of a single-isomer hydrofluoroether (HFE) comes primarily from how it is manufactured, not simply from having one isomer instead of two.

Legacy dual-isomer HFE fluids such as 3M™ Novec™ 7100 and 7200 were produced using electrochemical fluorination (ECF), a process associated with the generation of long-chain per- and polyfluoroalkyl substance (PFAS) byproducts such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). These long-chain compounds are targeted by global regulation as persistent organic pollutants.

BestSolv® single-isomer HFE fluids are produced using a targeted catalytic synthesis that avoids the generation of these long-chain PFAS manufacturing byproducts. The process also produces a high-purity single isomer, improving lot-to-lot chemical consistency while maintaining the physical properties needed for many legacy HFE applications.

This makes single-isomer HFE technology a more controlled manufacturing approach that can provide both greater chemical consistency and reduced generation of undesirable long-chain PFAS byproducts.