“Consisting Of” Claim Transition Does Not Exclude Unclaimed Impurities

Conoco v. EEI (Fed. Cir. 2006).

Conoco’s asserted claims were directed to drag reducing agents for gas pipelines.  EEI lost a bench trial and appealed on claim construction.  One claim in particular included the transition “consisting of” rather than the more open-ended “comprising.”

First, the CAFC refused to review the construction de novo because it had not been properly objected to at trial. Reviewing for clear error (substantial evidence) the appellate panel easily found that certain impurities found in the accused product did not allow EEI to escape infringement even though the closed “consisting of” language was used.

[I]mpurities that a person of ordinary skill in the relevant art would ordinarily associate with a component on the “consisting of” list do not exclude the accused product or process from infringement.

Affirmed.

4 thoughts on ““Consisting Of” Claim Transition Does Not Exclude Unclaimed Impurities

  1. 4

    David French writes:

    In Canada in the recent Federal Court Trial Division decision, ABBOTT LABORATORIES and RATIOPHARM, the court decided that:

    ” A person skilled in the art would understand the term “consisting essentially of” as used in claim 1, …… to mean that the composition contains all of the ingredients listed in the claim but it could include additional ingredients as well….”

    The difficulty presented by the Canadian Ratiopharm case is that the language “consists essentially of” is generally assumed by patent draftsmen to delimit a closed class of elements or components. This decision flies in the face of the general understanding of the patent community.

    As of August 18, 2006, the USPTO database shows 569,713 records wherein the claims use the expression “consisting of”, and 70,550 records wherein the claims use the expression “consisting essentially of”. On the same date, the Canadian patent office database shows 180,430 records wherein the claims use the expression “consisting of”, and 17,505 records wherein the claims use the expression “consisting essentially of”. Accordingly, these must be taken as well-recognized expressions.

    The MPEP section 2111.03 adopts the general understanding of this expression of the patent community in the United States. The CFCA in Conoco v Energy and Environmental International endorsed the policy of the US Patent Office Board of Appeals position that “consisting of” closes a claim to inclusion of materials other than those recited, except with respect to minor impurities, and confirmed the further qualification that “consisting of” does not exclude additional components or steps that are unrelated to the invention.

    However, this present Canadian Federal Court Ratiopharm decision is clearly at odds with this US standard for patent claim interpretation.

    This decision is more fully analyzed at http://www.CanadaPatentBlog.com

  2. 3

    Conoco owned a “consisting of claim” towards a method to reduce the friction of oil flowing through pipes. Basically, Conoco adds certain chemical components to the oil per the method claim to reduce the friction between the oil and the pipes. Faster pipe moving oil means faster oil transportation which means money savings.

    Asserted infringer EEI performed all the steps of the claim and also took the additional step of adding impurities.

    In general, a “consisting of” claim explicitly recites that no other chemical components may be included in the composition. However, the court found that chemical components (such as impurities) that a person of ordinary skill in the relevant art would ordinarily associate with one or more components on the “consisting of” list do not exclude the accused product or process from infringement. No chemical is 100% clean and usually contains impurities ordinarily associated with it.

    EEI’s performance of all the claim steps was infringement and EEI’s perofrmance of the additional step of adding impurities did not avoid infringement of a “consisting of” claim.

    EEI was affirmed liable by the Fed. Circuit. for infringement of Conoco’s 5,244,937 and 6,172,151 patents.

  3. 2

    It appears that the Court interpreted “consisting of” to mean “consisting essentially of.”

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