Hearing rumors (without any documentation) that some of the current products being used in the fire service are causing damage to the brass parts of foam proportioning systems, it was decided to conduct our own, DIY Eval of of products for brass reactivity.
WHAT TESTED – 2-3 oz of an assortment 100% foam concentrates that were made available. This eval includes concentrates promoted as Class A, Class A/B and Class B concentrates.
BRASS – small, roughly equal rectangles of .001 thickness, along with equal strips of .010 thickness brass.
EVAL – Initiated 4-1-25. The Evaluation might take 1+ yrs. The products will be evaluated approximately every 30 days. (Eval ended 2-1-26)
LOCATION – Samples are in glass jars with screw on plastic spill tight lids and the samples are placed on a shelf where the temperature remains fairy constant – 72-78 degrees F. for the Eval duration.
PURPOSE – Visual evaluation of concentrates reaction to brass – based on field rumors of some locally used products causing damage to foam proportioning systems.
Any color changes indicates a reaction that may or may not indicate brass corrosion.
If you have any questions regarding your concentrates and your foam proportioning system, contact your system manufacture for information about acceptable products.
Also, insure you check the viscosity of your product and compare it to the manufacturer’s recommendations on viscosity limits. Some of the products in this DIY Eval appear rather thick.
The above photo shows the concentrates and corrosponding changes in color from Day 1, to Day 30, to Day 221.
Below is a jar by jar photo line up of each concentrate on day 306 (The last day of the evaluation). The jars were all photographed using the same natural light.
What do the changes in color mean? Good guess. It would take a labortory to identify exactly what is happening. However, for a DIY Eval, it is a good assumption that something is happening.
Below is a list of SDS Links for products observed.
