As major winter storms approach, it is important to plan beyond just slippery sidewalks and transit delays. Winter storms bring other challenges, including accelerated corrosion of metal surfaces. From bridges, cars, and utility equipment, winter’s salty conditions can hasten rust and degradation. ASTM B117-26: Standard Practice for Operating Salt Spray (Fog) Apparatus is a critical, widely used standard for evaluating and designing materials meant to withstand harsh, corrosive environments—particularly for evaluating protective coatings and metal performance.
Corrosion: A Hidden Cost of Winter Salt
Corrosion is the natural, gradual degradation of materials (most commonly metals) due to reactions with the environment— most commonly oxygen and chloride ions from salt. Degradation implies deterioration of physical properties of the material, which leads to material weakening or failure.
Corrosion becomes highly prevalent during winter storms due to a combination of moisture, freezing temperatures, and the widespread use of de-icing chemicals. These elements create an ideal environment for rapid oxidation, attacking vehicles, machinery, and infrastructure, particularly the undercarriages of vehicles and structural joints. Furthermore, in the winter, corrosion is significantly accelerated by road salt (sodium chloride), which lowers the freezing point of water, allowing corrosive slush to cling to vehicles and infrastructure longer. The presence of road salt from plowing and de-icing dramatically increases corrosion rates during and after winter storms, leading to higher maintenance costs and safety risks.
Importance of Salt Spray (Fog) Testing During Winter Storms
As winter storms roll through, the impact of road salt on metal assets is more than just a seasonal nuisance. It is a corrosion risk that affects safety, performance, and long-term costs. Salt spray (fog) testing is a critical, standardized method used to accelerate the corrosion process, allowing manufacturers to quickly evaluate the durability and corrosion resistance of materials, coatings, and surface treatments. By simulating harsh, saline environments, such as marine or de-icing salt exposure, it provides a comparative benchmark for how well a component or coating will resist corrosion over time.
ASTM B117-26 salt spray (fog) testing offers a standardized way to assess corrosion resistance, so that materials and coatings can be chosen, validated, and improved with confidence.
What Is ASTM B117-26?
ASTM B117-26 provides a standardized, accelerated, and reproducible salt spray (fog) test method for quality control. This practice covers the apparatus, procedure, and conditions required to create and maintain the salt spray (fog) test environment.
This practice does not prescribe the type of test specimen or exposure periods to be used for a specific product, nor the interpretation to be given to the results
You can learn more about ASTM B117-26 in our blog post: ASTM B117-26: Standard Practice for Operating Salt Spray (Fog) Apparatus.
How Is ASTM B117-26 Used During and After a Winter Storm?
ASTM B117-26 is used during and after winter storm preparations as a standardized accelerated corrosion test to simulate the harsh, salty environment created by road de-icing salts on vehicles, infrastructure, and coatings. It is not used during an actual, live winter storm, but rather in laboratories to evaluate how well materials will withstand the corrosive conditions of winter. ASTM B117-26 establishes guidelines for creating a controlled corrosive environment to evaluate how well metals and coated metals resist corrosion. In a salt spray chamber, a fine mist of salt solution simulates highly corrosive, salty conditions similar to those experienced in coastal environments or on winter-salted roads.
Although the standard does not prescribe how to interpret results or specify exposure durations, ASTM B117-26 defines the apparatus and procedures to reliably generate salt fog and keep test conditions consistent. This consistency is key to comparing materials, coatings, and products for relative corrosion resistance.
Why Salt Spray Testing Alone Doesn’t Capture All Real-World Conditions
It is important to note that while ASTM B117-26 provides a consistent corrosive environment, its results do not always correlate directly with real field performance on their own. Real world conditions, including temperature fluctuations, wet-dry cycles, UV exposure, and variable salt compositions, are more complex than what a standard salt fog chamber reproduces. Therefore, salt spray (fog) testing is best used as one part of a comprehensive corrosion evaluation strategy, often paired with long-term atmospheric exposure tests or other accelerated weathering methods.
How ASTM B117-26 Helps Prepare for Winter
With ASTM B117-26, engineers and manufacturers can:
Evaluate Coatings and Materials Before They Meet the Storm
Salt spray (fog) testing accelerates corrosion in a controlled setting, so manufacturers can screen coatings, paints, plating, and base metals for performance. This helps assure that vehicle parts, structural fasteners, street signage, and outdoor equipment have the corrosion resistance needed to survive repeated winter salt exposure.
Compare Relative Performance Across Designs
Rather than waiting months or years to see how a product performs outside, salt spray (fog) tests can highlight weaknesses in materials early in the design or quality control process. This is crucial for components that must remain reliable during a harsh winter environment.
Support Infrastructure Longevity
Municipalities and builders can use salt spray data to choose more resilient materials for bridges, guardrails, electrical enclosures, and public transit assets— all parts of the urban fabric exposed to corrosive conditions in winter.
Where To Find ASTM B117-26
Whether you are an engineer specifying coatings, a manufacturer optimizing product durability, or a municipal planner safeguarding infrastructure, understanding and applying salt spray (fog) testing helps assure that your assets are ready and resilient when a harsh winter storm hits.
ASTM B117-26: Standard Practice for Operating Salt Spray (Fog) Apparatus is available on the ANSI Webstore.