In their latest Law360 column on recent notable Federal Circuit decisions, Knobbe Martens partners Jeremiah Helm and Sean Murray analyze the Federal Circuit’s decision in Enviro Tech Chemical Services, Inc. v. Safe Foods Corp., a case that hinged on the word “about”, and its implications for patent claim indefiniteness under 35 U.S.C. § 112. The court’s ruling in the patent dispute between two chemical processing companies, Enviro Tech Chemical Services and Safe Foods Corporation, “illustrates the danger in attempting to expand claim scope with words of approximation,” they write.
Helm and Murray explain how Enviro Tech’s patent at issue, directed to methods of processing poultry in a chemical bath, used the term “about” to define the required pH range for the claimed process. While it can be beneficial to use this type of approximation language in a patent claim, the authors note that it can also render the claim invalid for lack of definiteness, as was the case in Enviro Tech.
The authors offer several key takeaways for practitioners and patent holders regarding the use of approximation terms in patent claim drafting. “A patentee must temper the desire to expand claim scope using language of approximation with the requirement that claims must have defined boundaries,” they suggest. Further, in instances where terms like “about” or “approximately” are included in the patent claim, the authors recommend drafting specifications defining these terms. Finally, they write, “practitioners may want to sidestep indefiniteness problems entirely by avoiding words of approximation during claim drafting.”
Read the full Law360 article, “Being Precise About ‘About’”, here.
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