What are PFAS Chemicals?
This BestSolv® Engineered Fluid is NOT considered a PFAS (per- and polyfluoroalkyl substance) under the U.S. EPA’s currently proposed definition.
BestSolv® nPB – High-Performance Cleaning Solvent for Critical Applications
BestSolv® nPB is a non-flammable solvent designed for vapor degreasing and general-purpose cleaning where high cleaning strength and residue-free performance are essential. Used across industries such as medical device manufacturing, aerospace, electronics, it effectively removes oils and greases from components such as oxygen service systems, precision optics and high vacuum systems.
As a powerful replacement for TCE, perchloroethylene, and methylene chloride, BestSolv® nPB offers outstanding cleaning efficiency with a low environmental footprint and proven material compatibility.
Benefits of BestSolv® nPB
- Drop-in replacement for TCE, perchloroethylene, and methylene chloride
- Non-flammable and non-conductive
- Low surface tension penetrates tight part geometries
- Leaves virtually no residue (conforms to SAE ARP1176)
- High dielectric strength
- Compatible with most metals and many plastics
- Distillable azeotropic mixture enables reuse across cleaning cycles
- U.S. EPA SNAP-approved solvent
- Low Global Warming Potential (GWP: 0.31)
- Very low Ozone Depletion Potential (ODP: 0.005)
- Rapid biodegradation in air, water, and soil
Data Sheets
| Type | |
Safety Data Sheet | |
Technical Data Sheet |
Environmental Impact
BestSolv® nPB offers strong environmental performance for a solvent of its class:
- Air: Evaporates quickly; atmospheric lifetime ~25 days
- Water: Hydrolyzes in 26 days; minimal bioaccumulation (BCF = 23)
- Soil: High volatility ensures rapid evaporation and breakdown
Common Applications

BestSolv® nPB effectively cleans contaminants such as cutting oils, stamping oils, and hydraulic and mineral oils. It is a powerful option for cleaning and degreasing in precision manufacturing environments:
- Vapor degreasing of aerospace and medical device components
- Oxygen service line and valve cleaning
- Ultrasonic cleaning of high-vacuum parts
- Electronics assembly and maintenance
- Optical and instrument cleaning
Materials Compatibility
Tested and proven for compatibility with:
- Metals: Stainless steel, titanium, copper, carbon steel, aluminum – PASSED corrosion testing
- Plastics: Teflon®, Nylon, Mylar®, Ultem® – Acceptable in immersion and vapor degreasing
- Elastomers: Viton®, Chemraz®, Silicone (vapor use), Buna-N – Little or no change
Not recommended for use with:
- ABS, Acrylic, Lexan, and Polystyrene plastics
- Natural rubber, Neoprene (significant degradation)
Material compatibility testing should always be performed with specific contaminants under process-specific conditions. A full compatibility chart is available on request.
nPB Phase Out in Progress
Hazard alerts and phase-out actions have been issued for nPB by OSHA, NIOSH and other government agencies. Despite these risks, we recognize that some companies still rely on nPB for economic or short-term production needs—particularly when transitioning to a safer alternative takes time. That’s why we offer BestSolv® nPB as a lower-cost cleaning solvent for approved applications.
- Available now for customers still using nPB-based systems
- Lower cost than most drop-in replacements
- Ideal for organizations nearing transition or needing interim supply
We strongly encourage customers to treat this as a transitional solution only. Our long-term recommendation remains a shift to safer alternatives, such as BestSolv® Bravo.
BestSolv® Bravo replaces nPB
For companies ready to move beyond nPB, BestSolv® Bravo is a heavy-duty cleaning solvent that effectively cleans contaminants such as oils, greases, silicones, flux residues and waxes, while allowing businesses to align with environmental regulations.
- No EPA hazardous designation
- No OSHA hazard alert
- Not subject to European phase-out
- Drop-in performance with no equipment change required
Comparison: BestSolv® Bravo vs. BestSolv® nPB
| Property | BestSolv® Bravo | BestSolv® nPB |
| Cost Comparison | $$ | $ |
| Composition |
|
|
| Replacement For | 3M™ Novec™ 73DE | TCE, methylene chloride, perchloroethylene |
| Cleaning Performance | Heavy Duty | Heavy Duty |
| Boiling Point | 113.9 °F / 45.5 °C | 158 °F / 70 °C |
| Stability | Near Azeotrope | Azeotropic – reusable |
| Vapor Pressure | 292 mmHg @ 25 °C | 134 mmHg @ 25 °C |
| Liquid Density | 1.27 g/cm2 | 1.31 g/mL @ 75 °F |
| Surface Tension | 19 dynes/cm | Low (not specified) |
| Kauri-Butanol Value | 94 Kb | 130 Kb |
| Global Warming Potential (GWP) | Low | Very Low (0.31) |
| Ozone Depletion Potential (ODP) | None | Very Low (0.005) |
| Volatile Organic Compound (VOC) Designation | Yes – 1,2 trans DCE is a VOC. | Yes – nPB is a VOC. |
| Flash Point | None | None |
| Material Compatibility | Broad range – plastics, metals, elastomers | Broad range – metals, many plastics/elastomers |
BestSolv® nPB Packaging
| Product # | SKU | Container Sizes Available (Gallons) |
| BestSolv® nPB | 2500000055 | 55 gal. drum |
BestSolv® Price and Ordering
For purposes of product stewardship, BestSolv® Engineered Fluids cannot be sold directly online.
Please contact our chemical sales department for a quote by clicking the “Get a Quote” button, or call 612-392-2414, ext. 2.








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