27.1 Introduction: limitations in current CIP systems
A cleaning-in-place (CIP) system can be only as effective as its design,
construction, installation and operation. There are a number of opportunities to
minimize or eliminate the limitations in today's CIP systems through improved
hygienic design. Design personnel need to be familiar with good manufacturing
practice (GMP), Hazard Analysis Critical Control Point (HACCP) methods, and
the hygienic design criteria and principles laid down by the European Hygienic
Engineering and Design Group (EHEDG, Documents 9, 10, 13, 14, 16, 17, 18,
20 and 25). All components that come into contact with product and/or the CIP
system should be designed according to the Hygienic Equipment Design Criteria
(EHEDG Document 8).
Engineering, installation and process parameters are directly related to
hygienic design, and influence the hygienic and functional integration of all
elements of the CIP system. If the design and installation of the plant result in
the presence of pits, crevices, gaps, sharp edges, threads and/or dead ends,
cleaning time will be greatly increased and there will be a risk of
contamination.
Inadequate or inaccurate installation and the presence of porous or rough
surfaces may allow bacterial colonies to proliferate, or permit the build-up of
biofilm (substances excreted by bacteria to improve their ability to adhere to
surfaces) and plaque. Cleaning and disinfecting fluids can only attack the top
surface of the biofilm. Bacteria in a biofilm cannot be killed by saturated steam
at 121 ÎC for 30 minutes, and thus, under normal operating conditions, these
sections cannot be sterilized and there is a serious risk of contamination of the
product. The T-joint is one example where there is a major risk of insufficient
27 Improvingcleaning-in-place(CIP)
K. Lorenzen, Tuchenhagen GmbH, Germany