DCT
1:24-cv-01313
Envirotech Chemical Services Inc v. Clean Chemistry Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: EnviroTech Chemical Services, Inc. (California)
- Defendant: Clean Chemistry, Inc. (Delaware)
- Plaintiff’s Counsel: Eversheds Sutherland (US) LLP
- Case Identification: 1:24-cv-01313, W.D. Tex., 10/29/2024
- Venue Allegations: Venue is alleged in the Western District of Texas because Defendant resides in the district, maintaining its principal place of business there, and has allegedly committed acts of infringement within the district.
- Core Dispute: Plaintiff alleges that Defendant’s PeroxyMAX peracetic acid products, and the process used to manufacture them, infringe four patents related to methods and compositions for generating non-equilibrium peracetic acid on-site.
- Technical Context: The technology concerns the on-demand chemical generation of peracetic acid, a versatile disinfectant, aiming to circumvent the safety, regulatory, and logistical challenges of transporting and storing its pre-mixed, stabilized forms.
- Key Procedural History: The complaint states that on May 20, 2024, Plaintiff sent a letter to Defendant identifying the four patents-in-suit and demanding that Defendant cease its allegedly infringing activities, which establishes a basis for the willfulness allegations.
Case Timeline
| Date | Event |
|---|---|
| 2011-03-24 | Earliest Priority Date for ’449, ’997, ’443, and ’072 Patents |
| 2013-10-01 | U.S. Patent No. 8,546,449 Issues |
| 2016-06-14 | U.S. Patent No. 9,363,997 Issues |
| 2017-08-15 | U.S. Patent No. 9,730,443 Issues |
| 2017-08-22 | U.S. Patent No. 9,737,072 Issues |
| 2024-02-01 | Defendant Submits FCN 2352 to FDA Describing Accused Process |
| 2024-05-20 | Plaintiff Sends Notice Letter to Defendant |
| 2024-10-29 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,546,449 - Methods and Compositions for the Generation of Peracetic Acid On Site at the Point-Of-Use
The Invention Explained
- Problem Addressed: The patent’s background describes the significant drawbacks of using traditional, pre-mixed "equilibrium" solutions of peracetic acid (PAA). These drawbacks include high transportation and storage costs due to low PAA concentrations, product instability, and extensive regulatory burdens associated with hazardous materials. Prior on-site generation methods are described as complex, capital-intensive, and potentially unsafe. (’449 Patent, col. 3:11-4:40).
- The Patented Solution: The invention claims a method to generate a "non-equilibrium" PAA solution safely and efficiently at the point of use. The process involves introducing a pre-formed solution containing hydrogen peroxide and an acetyl precursor (triacetin) into water, mixing them, and then adding an aqueous alkali metal hydroxide (e.g., sodium hydroxide) to catalyze a rapid reaction that produces PAA. (’449 Patent, Abstract; col. 13:32-14:67).
- Technical Importance: This on-demand approach was designed to provide end-users with a safer, more economical, and less regulated way to produce PAA for disinfection compared to transporting stabilized PAA or using prior complex on-site generation systems. (’449 Patent, col. 5:36-50).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶19).
- The essential elements of claim 1 are:
- A method of generating non-equilibrium solution of peracetic acid, comprising:
- providing water;
- introducing a hydrogen peroxide-triacetin solution to the water;
- mixing the hydrogen peroxide-triacetin solution and the water to form a mixture;
- adding an aqueous source of an alkali metal or earth alkali metal hydroxide to the mixture; and
- forming a reaction medium comprising a non-equilibrium solution of peracetic acid.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 9,363,997 - Methods and Compositions for the Generation of Peracetic Acid On Site at the Point-Of-Use
The Invention Explained
- Problem Addressed: As a continuation of the same inventive effort, this patent addresses the same technical problems as the ’449 Patent: the inefficiencies, costs, and hazards associated with stabilized, equilibrium PAA solutions and previous on-site generation technologies. (’997 Patent, col. 3:12-4:48).
- The Patented Solution: The method described is nearly identical to that of the ’449 Patent, involving the on-site combination of water, hydrogen peroxide, triacetin, and an alkali source to rapidly generate PAA. A key distinction in the claims is that this patent covers the introduction of triacetin and aqueous hydrogen peroxide as separate components to the water, rather than as a pre-formed solution. (’997 Patent, Abstract; claim 1). The general process flow is depicted in the patent’s Figure 1. (’997 Patent, Fig. 1).
- Technical Importance: The invention provides an alternative claimed method for achieving the same goal of safe and efficient on-demand PAA generation, potentially offering greater flexibility in how the precursor chemicals are handled and introduced. (’997 Patent, col. 6:45-56).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶37).
- The essential elements of claim 1 are:
- A method of generating a non-equilibrium solution of peracetic acid, comprising:
- providing water;
- introducing triacetin and aqueous hydrogen peroxide to the water;
- mixing the triacetin and the aqueous hydrogen peroxide with the water to form a mixture;
- adding an aqueous source of an alkali metal or earth alkali metal hydroxide to the mixture; and
- forming a reaction medium comprising a non-equilibrium solution of peracetic acid.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 9,730,443 - Methods and Compositions for the Generation of Peracetic Acid On Site at the Point-Of-Use
- Technology Synopsis: This patent claims the resulting chemical composition itself, rather than the method of making it. It protects a "non-equilibrium solution of peracetic acid" comprising the key reactants (hydrogen peroxide, triacetin, alkali source, water) and reaction products (peracetic acid, 1,2,3-propanetriol). (’443 Patent, Abstract; claim 1).
- Asserted Claims: The complaint asserts independent claim 1 (Compl. ¶51).
- Accused Features: The complaint alleges that the final PeroxyMAX product is a solution that contains all the chemical components required by claim 1 of the ’443 Patent (Compl. ¶¶52-65).
U.S. Patent No. 9,737,072 - Methods and Compositions for the Generation of Peracetic Acid On Site at the Point-Of-Use
- Technology Synopsis: This patent claims an intermediate composition used in the on-site generation process. It protects a "hydrogen peroxide-acetyl precursor solution" comprising aqueous hydrogen peroxide, triacetin, water, and a trace amount of peracetic acid that may form during storage. (’072 Patent, Abstract; claim 1).
- Asserted Claims: The complaint asserts independent claim 1 (Compl. ¶67).
- Accused Features: The complaint alleges that Defendant’s Accused Process necessarily forms this claimed intermediate precursor solution when the reactants are mixed, prior to the final formation of peracetic acid (Compl. ¶¶68-69, 75).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are Defendant’s "PeroxyMAX" product ("Accused Product") and the manufacturing process used to create it ("Accused Process") (Compl. ¶¶16-17).
Functionality and Market Context
- The complaint alleges the Accused Process is detailed in an Environmental Assessment for Food Contact Notification (FCN 2352) submitted to the FDA (Compl. ¶17). According to the complaint’s description of this document, the process generates a non-equilibrium peracetic acid solution on-demand. The complaint includes Figure 1, an excerpt from the FCN, which states the process "eliminates the need to incorporate a stabilizer" because the product is "produced and used on-demand" (Compl. ¶21). The process steps are described as: 1) feeding water into a generator/mixer, 2) adding concentrated sodium hydroxide, 3) blending in hydrogen peroxide, and 4) adding triacetin under continuous agitation (Compl. ¶¶25, 27, 33).
- The complaint alleges that the Accused Product directly competes with Plaintiff’s offerings in the market for peracetic acid solutions (Compl. ¶14).
IV. Analysis of Infringement Allegations
U.S. Patent No. 8,546,449 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| providing water | The Accused Process begins by feeding water into a generator/mixer to serve as the base of the solution. | ¶25 | col. 14:41-43 |
| introducing a hydrogen peroxide-triacetin solution to the water | The Accused Process separately adds hydrogen peroxide and triacetin to the water, which is alleged to be equivalent to introducing a pre-made solution. | ¶¶27-28 | col. 14:56-61 |
| mixing the hydrogen peroxide-triacetin solution and the water to form a mixture | The blending of hydrogen peroxide and addition of triacetin under continuous agitation in the water-based solution is alleged to form a mixture of the ingredients. | ¶31 | col. 14:46-55 |
| adding an aqueous source of an alkali metal or earth alkali metal hydroxide to the mixture | The Accused Process adds concentrated sodium hydroxide, which is an alkali metal hydroxide, to the water to create an alkaline environment. | ¶33 | col. 14:56-62 |
| forming a reaction medium comprising a non-equilibrium solution of peracetic acid | When sodium hydroxide, hydrogen peroxide, and triacetin are combined in water, they allegedly react rapidly to form a non-equilibrium solution of peracetic acid. | ¶35 | col. 15:23-32 |
Identified Points of Contention
- Scope Questions: The complaint’s theory against the ’449 Patent relies on the doctrine of equivalents. The Accused Process is alleged to add hydrogen peroxide and triacetin sequentially, whereas claim 1 recites introducing a pre-formed "hydrogen peroxide-triacetin solution" (Compl. ¶28). The central dispute will be whether the separate addition of components performs substantially the same function (providing reactants) in substantially the same way (delivering them to the reaction) to achieve substantially the same result (on-demand PAA generation), raising the question of whether this difference is insubstantial.
- Technical Questions: A related question is whether the sequence of addition in the Accused Process—adding sodium hydroxide to water before adding the other reactants—is technically distinct from the method claimed in the patent. The complaint asserts that the order of addition is "insubstantial" (Compl. ¶36).
U.S. Patent No. 9,363,997 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| providing water | The first step of the Accused Process is providing water to be the base of the solution. | ¶41 | col. 14:41-43 |
| introducing triacetin and aqueous hydrogen peroxide to the water | The Accused Process requires the addition of both hydrogen peroxide and triacetin to the process. Figure 4 of the complaint illustrates the addition of triacetin to the process (Compl. ¶43). | ¶43 | col. 16:41-43 |
| mixing the triacetin and the aqueous hydrogen peroxide with the water to form a mixture | The "blending" of hydrogen peroxide into the alkaline solution and the addition of triacetin under "continuous agitation" is alleged to necessarily form a mixture of the ingredients with water. | ¶45 | col. 16:49-55 |
| adding an aqueous source of an alkali metal or earth alkali metal hydroxide to the mixture | The Accused Process adds concentrated sodium hydroxide to the water, providing an alkaline environment. | ¶47 | col. 16:56-61 |
| forming a reaction medium comprising a non-equilibrium solution of peracetic acid | When all reactants are present in the water-based solution, they allegedly react to form an aqueous mixture of peracetic acid. | ¶49 | col. 17:13-22 |
Identified Points of Contention
- Scope Questions: The infringement theory for the ’997 Patent appears to be for literal infringement, as claim 1 recites introducing the reactants separately. However, a potential dispute may arise over the sequence of steps. The claim recites adding the alkali source (step d) after forming a mixture of water, triacetin, and hydrogen peroxide (step c). The Accused Process allegedly adds the alkali source to the water before adding the other reactants. This raises the question of whether the claimed sequence is a required limitation of the method.
- Technical Questions: The complaint alleges that switching the order of addition is "insubstantial" and "equivalent" (Compl. ¶50). This suggests an awareness that the sequence of steps may be a point of contention and prepares an alternative argument under the doctrine of equivalents if a court finds the sequence is a material part of the claim that is not literally met.
V. Key Claim Terms for Construction
"hydrogen peroxide-triacetin solution" (’449 Patent, claim 1)
- Context and Importance: The construction of this term is dispositive for the literal infringement analysis of the ’449 Patent. If the term is construed to require a single, pre-mixed liquid, then the Accused Process—which allegedly adds the components separately—would not literally infringe. Practitioners may focus on this term because it is the primary distinction between the claims of the ’449 and ’997 patents and the focal point of the doctrine of equivalents argument.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the function of the components as providing hydrogen peroxide and an acetyl precursor for a reaction, which could support an argument that the precise form of introduction is less important than the presence of the required chemicals. (’449 Patent, col. 5:10-25).
- Evidence for a Narrower Interpretation: The claim language uses the singular "a ... solution," suggesting a single entity. The specification explicitly describes a method of "preparing a hydrogen peroxide-acetyl precursor solution" by mixing the components as a distinct preparatory step before introducing it to the water, which could support a construction requiring a pre-mixed liquid. (’449 Patent, col. 8:56-9:14).
"mixing the triacetin and the aqueous hydrogen peroxide with the water to form a mixture" (’997 Patent, claim 1)
- Context and Importance: The construction of this term, particularly its sequential relationship to the step of "adding an aqueous source of an alkali metal...hydroxide," is critical for the literal infringement analysis of the ’997 Patent. If the claim is construed to require the formation of a three-part mixture (water, triacetin, H₂O₂) before the alkali is added, the Accused Process may not literally infringe, as it allegedly adds the alkali to the water first.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent describes the overall process as a rapid, on-site reaction where components are brought together. An argument could be made that the sequential "a, b, c, d" format is merely a way of listing necessary steps, not a rigid temporal sequence, especially given the near-instantaneous nature of the mixing and reaction. (’997 Patent, col. 6:1-3).
- Evidence for a Narrower Interpretation: The plain language of the claim presents the steps in a clear sequence (a, b, c, d). Standard principles of claim construction suggest that sequential steps in a method claim should be performed in the order recited unless the specification indicates otherwise. The claim requires forming "a mixture" in step (c) and then "adding an aqueous source...to the mixture" in step (d), which suggests the mixture from (c) exists before the addition in (d). (’997 Patent, claim 1).
VI. Other Allegations
- Indirect Infringement: The complaint does not contain specific factual allegations to support claims of induced or contributory infringement, such as allegations that Defendant instructs its customers to perform an infringing method. The prayer for relief, however, seeks a judgment that Defendant has infringed "directly or indirectly" (Compl. p. 22, ¶B).
- Willful Infringement: The complaint alleges willful infringement for all four patents-in-suit. The basis for this allegation is Defendant's alleged actual notice of the patents as of "at least May 20, 2024," the date of Plaintiff's cease-and-desist letter, and its continued infringement thereafter (Compl. ¶¶80-81, 85-86, 90-91, 95-96).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope and equivalence: For the ’449 patent, can the claim term "hydrogen peroxide-triacetin solution" be met under the doctrine of equivalents by the accused process of adding the two chemical components separately? The outcome will depend on whether this difference in the way the reactants are introduced is legally and technically insubstantial.
- A second central question will be one of claim interpretation and sequence: For the ’997 patent, does the claim language require a rigid sequence where water, triacetin, and hydrogen peroxide are mixed to form a distinct mixture before an alkali source is added? The analysis will focus on whether the accused process, which allegedly adds the alkali to water first, meets this claim limitation literally.
- A key strategic question will be the interplay between the asserted patents: Plaintiff has asserted a family of patents with progressively different claim scopes—a method requiring a pre-mixed solution (’449), a method requiring separate additions (’997), a final product composition (’443), and an intermediate composition (’072). This "picket fence" approach raises the question of whether at least one of these claim sets was drafted broadly enough to capture the specific combination of steps and ingredients used in the Accused Process and Product.