Background
Enviro Tech Chemical Services, Inc. sued Safe Foods Corp. alleging infringement of its United States Patent ten comma nine one two comma three two one. The district court determined that the asserted claims were invalid because the terms an antimicrobial amount and about were indefinite. Enviro Tech appealed the decision.
The court’s reasoning
The court reviewed the indefiniteness determination de novo. It held that while words of approximation like about are not inherently indefinite, the parameter range must be reasonably certain based on the technological facts of the particular case. The court found that the patent specification provided conflicting guidance on pH deviations, with some experiments allowing deviations greater than zero point three and others strictly adhering to that limit. Additionally, the prosecution history was inconsistent, as Enviro Tech sometimes argued the term was material and other times omitted it entirely. The court concluded that the intrinsic evidence did not inform a skilled artisan of the scope of about with reasonable certainty.
What it means going forward
The ruling reinforces that patent applicants must provide clear, consistent, and specific guidance in the specification and prosecution history when using terms of approximation to define claim parameters.
Podcast (federal-narrative-summaries): Play in new window | Download