A new risk analysis of Clean-In-Place milk processing

A Friday 13th failure assessment of clean-in-place removal of whey protein deposits from metal surfaces with auto-set cleaning times

“…An advantage with CIP is that there is no need to dismantle equipment; this reduces the time for cleaning (Lloyd, 2008). Currently, CIP is done by forced-circulation of chemical solutions (alkali and acid) and post-treatments with water (Alvarez et al, 2009;Davey et al, 2013). In automated CIP, the cleaning time is auto-set by the plant based on the particular alkali and acid temperature used.…”

“…These failures cannot be put down to "human error" or "faulty fittings" (Cerf and Davey, 2001;Davey, 2010Davey, , 2011. In recent years Davey and co-workers (Davey et al, , 2013Davey, 2010Davey, , 2011Patil, 2006;Patil et al, 2005) have illustrated a new risk assessment that addresses this that they titled Friday 13th (Fr 13) failure. A key insight with Fr 13 risk assessments is that an accumulation of stochastic (random) changes in otherwise well-operated continuous plant can accumulate in one-direction and unexpectedly leverage unwanted and sudden (surprise) change in product or process.…”

“…A key insight with Fr 13 risk assessments is that an accumulation of stochastic (random) changes in otherwise well-operated continuous plant can accumulate in one-direction and unexpectedly leverage unwanted and sudden (surprise) change in product or process. Case studies have included a sudden failure of sterile milk to a nonsterile product (Davey and Cerf, 2003); stable to sudden unstable fermenter operation with "washout" (Patil et al, 2005); from clean to unclean (CIP) processing (Davey et al, , 2013; and more generally, from safe to unsafe (Davey et al, 2013). Importantly, these published examples underscore that Fr 13 failure does not need to imply actual breakage of continuous plant or even its shutdown (Davey et al, 2013;Davey, 2010).…”

“…Current assessments include HACCP (Hazard Analysis Critical Control Point), HAZOP (HAZard and OPerability) and Reliability Engineering (O'Connor et al, 2002). These however have a number of drawbacks that have been discussed in detail elsewhere (Davey, 2010(Davey, , 2011Davey et al, 2013;Abdul Halim and Davey, 2015). Broadly, results are often only semi-quantitative and don't address random effects.…”

“…In contrast with current assessments, in Fr 13 assessments both the facts about the process and the effects of random changes in parameters are separated (Hoffman and Hammonds, 1994;Ria and Krewski, 1998;Davey et al, 2013). This is more mathematically correct than traditional methods as it permits both the effect of chance and stochastic variability to be studied and thereby new and potentially valuable process insight to be gained.…”