Brita LP v. Int’l Trade Comm’n
Authored by: Jeremy J. Gustrowsky
In a recent decision, the U.S. Court of Appeals for the Federal Circuit upheld a ruling from the International Trade Commission (ITC) that struck down several claims in Brita LP’s patent for gravity-fed water filters. The case stemmed from Brita’s challenge against competitors like LifeStraw, Kaz USA, and Helen of Troy, who were accused of importing products that infringed the patent. The ITC found the claims invalid, and the Federal Circuit agreed, focusing on flaws in how the patent described and explained its invention.
The patent in question, U.S. Patent No. 8,167,141, covers water filters using activated carbon and a lead scavenger to remove contaminants while maintaining a good flow rate. It introduces a performance measure called the FRAP factor—a formula balancing filter volume, filtration time, lead removal efficiency, and lifespan—to ensure filters work quickly without sacrificing effectiveness. However, the patent only provided examples and details for carbon-block filters achieving this FRAP factor of 350 or less, while broadly claiming it could apply to other filter types like mixed media or granular ones.
The court ruled that the patent failed the “written description” requirement because it didn’t show the inventors truly possessed the full scope of their claims. The court said the patent must demonstrate that the inventor “possessed” or invented the full range of filter type rather than essentially wishing the other types would work without showing how or proving they did. Here, the specification praised carbon blocks as “unique” for meeting the FRAP standard and highlighted problems with other media, like poor lead removal or slow flow. Inventor testimony confirmed no non-carbon-block versions were created, leaving a skilled person unable to visualize how to extend the invention beyond carbon blocks.
On enablement, the court found the patent didn’t teach how to make or use non-carbon-block filters without excessive trial and error. The FRAP formula’s variables—such as volume and lead concentration—are interconnected in unpredictable ways, making it hard to tweak other media types reliably. The patent offered no roadmap for overcoming these hurdles, dooming the claims to invalidity. The Federal Circuit didn’t address indefiniteness, as the other issues were enough to affirm the ITC’s no-violation finding.
This ruling underscores the need for patents to fully explain and support broad claim language with concrete examples, especially where the technology discussed includes examples that may involve additional experimentation to be effective.