PTAB

IPR2025-01458

Clean Chemistry, Inc. v. Enviro Tech Chemical Services, Inc.

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods and Compositions for the Generation of Peracetic Acid on Site at the Point-of-Use
  • Brief Description: The ’072 patent describes methods for generating peroxyacetic acid (PAA) using a precursor solution. The claims are directed to a "hydrogen peroxide-acetyl precursor solution" comprising aqueous hydrogen peroxide, triacetin, water, and a trace amount of peracetic acid.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 are anticipated by and/or obvious over Okano

  • Prior Art Relied Upon: Okano (JP 2006-045147 A)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Okano, which teaches sterilizing compositions, discloses every element of the challenged claims. Okano’s Example 1 describes combining triacetin, aqueous hydrogen peroxide, and water. Petitioner contended that the reaction of these components necessarily forms peracetic acid, the fourth component of independent claim 1. Okano explicitly refers to the formation of an "organic peracid," which, given the use of triacetin as the precursor, must be peracetic acid.
    • Prior Art Mapping (Dependent Claims 2 and 3): Petitioner asserted that Okano discloses molar ratios and concentration ranges for hydrogen peroxide and triacetin that anticipate dependent claims 2 and 3. Specifically, Okano’s disclosed hydrogen peroxide to triacetin molar ratio of 0.05:1 to 10:1 overlaps with the range of about 2.98:1 to 12.84:1 in claim 2 and encompasses the specific ratio of about 3.8:1 in claim 3. Similarly, Petitioner showed that Okano’s disclosed concentration ranges for hydrogen peroxide (1% to 30%) and triacetin (20% to 90%) overlap with the ranges in claim 2 (23-40% and 20-53%, respectively) and encompass the specific concentrations in claim 3 (27% and 46%, respectively). Petitioner argued this creates a prima facie case of anticipation. In the alternative, Petitioner contended that because the claimed ranges overlap with those disclosed in Okano, claims 2 and 3 are obvious.

Ground 2: Claim 1 is anticipated by and/or obvious over Stauffer

  • Prior Art Relied Upon: Stauffer (WO 2011/017095 A2)
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Stauffer, which describes peracid-based antimicrobial compositions, anticipates or, in the alternative, renders obvious claim 1. Examples 4 and 5 of Stauffer teach combining aqueous hydrogen peroxide (30%), triacetin, and deionized water. In every experimental run, peracetic acid was detected after one minute, with the minimum detected amount being 114 ppm. Petitioner contended this amount constitutes the "trace amount of peracetic acid" required by claim 1, as it is significantly less than the 1% by weight threshold Petitioner proposed for a "trace amount" based on the ’072 patent’s specification. Therefore, Stauffer discloses a solution containing all four required components of claim 1.
    • Obviousness Argument: As an alternative, Petitioner asserted that even if not directly anticipating, Stauffer’s teachings would have made claim 1 obvious to a Person of Ordinary Skill in the Art (POSITA). A POSITA would have understood from Stauffer that combining water, triacetin, and aqueous hydrogen peroxide would result in the formation of at least a trace amount of peracetic acid, as Stauffer demonstrates this reaction occurs even in the absence of other components like enzymes or polyols.

4. Key Claim Construction Positions

  • "Trace amount": Petitioner argued this term is critical to the invalidity analysis and should be construed to mean an amount of peracetic acid less than about 1% by weight. This construction was based on the ’072 patent specification, which describes "a high level of PAA, from about 1% to about 7.1%." Petitioner inferred that if 1% or more is a "high level," then a "trace amount" must be less than 1%.
  • "Hydrogen peroxide-acetyl precursor solution": Petitioner proposed that this preamble phrase should be interpreted as a "hydrogen peroxide-triacetin solution." This construction was based on the specification, which identifies triacetin as the sole example of a liquid acetyl precursor used to form the solution.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-3 of the ’072 patent as unpatentable under 35 U.S.C. §102 and/or §103.