"Consisting Of" Allows Impurities Normally Associated with Invention

In Conoco v. Energy & Environmental International (August 17, 2006), the Federal Circuit reviewed the lower court’s infringement analysis for clear error and held that impurities that a person of ordinary skill would ordinarily associate with a component on the "consisting of" list do not exclude the accused product or process from infringement.

According to the opinion by Circuit Judge Gajarsa,

EEI contends that MIBK is not an impurity because it was purposely added to the alcohol to denature it. However, the intentional addition of a component does not change its status as an "impurity ordinarily associated therewith."

MIBK is a common impurity in industrial alcohols in order to prevent a liquor tax from being applied. If, however, MIBK had been added to adjust the stability of the suspending medium or prevent agglomeration of polymer, it may not have been an impurity and therefore EEI would most likely not infringe. Thus, impurities normally associated with the component of a claimed invention are implicitly adopted by the ordinary meaning of the components themselves. See Phillips, 415 F.3d at 1312-13 ("The ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art . . . .").

The district court found as a matter of fact that Alfol-2 consisted of water and alcohol and that any non-alcohol and non-water components, such as MIBK, were impurities. This conclusion was based on the testimony of EEI’s expert, who acknowledged that the small amounts of ammonia and heptane in the suspension were impurities and was impeached by prior testimony indicating MIBK was also an impurity. The court’s findings were based on the testimony of persons of ordinary skill in the art who testified that MIBK has little to no effect on the present invention and is normally associated with industrial alcohols to reduce tax liability.

Accordingly, there was substantial evidence to support the district court’s findings that the MIBK and the other non-alcohol/non-water components were impurities, and the district court did not clearly err by finding that Alfol-2 met the claim limitations of the suspending medium.

We are not presented with the question of whether impurities not normally associated with a component would exclude the accused process from infringement; however, as in Norian Corp., the additional component must be related to the invention. 363 F.3d at 1331-32.