Brita LP v. International Trade Commission

Brita LP v. International Trade Commission · United States Court of Appeals for the Federal Circuit · October 15, 2025 · No. 24-1098

Summary

The United States Court of Appeals for the Federal Circuit reviews an appeal from a United States International Trade Commission determination in Investigation No. 337-TA-1294 concerning Brita’s U.S. Patent No. 8,167,141 for gravity-flow water filters. The court addresses written-description, enablement, and indefiniteness issues involving claims directed to filters achieving a specified FRAP factor. The court affirms the Commission’s determinations of lack of written description and lack of enablement for non-carbon-block filter media.

Court
United States Court of Appeals for the Federal Circuit
Writing for the Court
Prost, Circuit Judge; Reyna, Circuit Judge; Chen, Circuit Judge
Jurisdiction
United States Court of Appeals for the Federal Circuit
Decision date
October 15, 2025
Docket number
24-1098
Procedural posture
Brita appealed a United States International Trade Commission decision determining claims 1–6 and 23 of U.S. Patent No. 8,167,141 invalid for lack of written description, lack of enablement, and indefiniteness.
Standard of review
The court reviews the Commission’s legal determinations de novo and its factual findings for substantial evidence. Enablement is reviewed de novo as a question of law based on underlying factual findings reviewed for substantial evidence.
Precedential value
Published and precedential Federal Circuit opinion
Parties
Brita LP v. International Trade Commission
Disposition
affirmed

Topics

patent lawjudicial review of agency actionadministrative lawappellate procedurestandard of review

Practice areas

patent lawpatent validityInternational Trade Commission practiceappellate review of agency action

Questions Presented

  1. Whether the asserted claims lacked adequate written-description support for non-carbon-block filter media capable of achieving the claimed FRAP factor.
  2. Whether the asserted claims were enabled as to non-carbon-block filter media without undue experimentation.
  3. Whether the court should reach the Commission’s indefiniteness determination.

Holdings

  1. The asserted claims lack adequate written-description support to the extent they encompass filter media other than carbon blocks that achieve the claimed FRAP factor.
  2. The asserted claims are not enabled as to non-carbon-block filters because practicing that full claim scope would require undue experimentation.
  3. The court declined to reach the indefiniteness issue because the Commission’s determination could be sustained on written-description and enablement grounds.

Key quotations

The ’141 patent’s disclosure does not demonstrate possession of non-carbon-block filter media achieving the claimed FRAP factor. (17)
The record thus supports the Commission’s legal conclusion that the ’141 patent required undue experimentation to enable the full scope of the asserted claims. (22)
We are not required to address every possible ground on which the Commission’s determination might be sustained. (22)

Factual background

The ’141 patent claims gravity-fed water filters containing activated carbon and a lead scavenger that achieve a specified Filter Rate and Performance (FRAP) factor of about 350 or less. Although the claims broadly covered filter media meeting the functional FRAP limitation, the patent disclosed working examples and detailed formulations only for carbon-block filters; tested mixed-media filters did not meet the claimed FRAP range. The record also showed that the FRAP variables were interrelated and unpredictable, and that the inventors had not created non-carbon-block filters achieving the claimed FRAP factor.

Procedural history

Brita filed a section 337 complaint alleging that respondents imported and sold water filters infringing claims of the ’141 patent. The administrative law judge found a section 337 violation and concluded that the asserted claims satisfied the written-description and enablement requirements. On respondents’ petition for review, the Commission determined that the relevant claim term was indefinite, that the asserted claims lacked written-description support for non-carbon-block filters, and that the claims were not enabled as to non-carbon-block filters; it therefore reversed the finding of a section 337 violation. The Federal Circuit affirmed the Commission’s written-description and enablement determinations and declined to reach indefiniteness.

Court Document

Open PDF
Loading document…