Takeaway: The Federal Circuit confirmed that Brita’s water filter patent is invalid for insufficient disclosure, reinforcing that patent claims must fully describe and enable all claimed aspects of an invention.

The Federal Circuit has upheld a U.S. International Trade Commission (ITC) ruling that Brita LP’s water filter patent is invalid for lacking adequate written description and enablement. The three-judge panel agreed that the patent, which claims a filtration system using materials such as activated carbon and a lead scavenger, failed to show that the inventors possessed or enabled the full range of claimed filter materials beyond carbon blocks. The court declined to address an additional indefiniteness finding, as the other issues were sufficient to invalidate the patent.

Brita, a subsidiary of The Clorox Co., had initially won before an ITC judge, alleging that Helen of Troy, Kaz USA, and LifeStraw infringed the patent, but the full ITC reversed that decision in 2023. The Federal Circuit’s affirmation means Brita cannot block imports of the accused products. Brita’s related district court suits remain stayed pending this outcome.