Why do we need to deep clean?

Hi, 
I am trying to prepare for the audit of FSSC 22000 by end of this year, one place I am getting stuck is sanitation. 
One of the common question I get is why do we deep clean if we run CIP on the equipment everyday. 

I gave them the answer as biofilms, but is there a easier solution.

Regards,

Kajal

In very general terms: alternate cleaning chemicals and physical procedures remove trace materials the standard ones don't, these traces don't pose a hazard at very low levels but need to be removed periodically to prevent greater accumulation.

Deep cleaning systems which are usually CIP also gives the opportunity to more thoroughly inspect areas which are out of view. CIP cleaning often includes a visual inspection as a routine, but in my experience some of this system is just out of view (piping systems and assemblies). That's why other means of verification like rinse water testing or chemical titrations are used to understand the effectiveness of CIP cleaning. Deep cleaning is a great opportunity to disassemble these systems to inspect for damage that may be occurring at a slow rate over time. 

I just wouldn't feel comfortable running CIPs on enclosed system for years without ever taking a look at what's inside. What knows what could be in there?

A full breakdown, cleaning and inspection is the BEST was to protect the overall equipment investment.

Damages, abnormal wear, as well as possible foreign material contamination can all be found at this time

and NO CIP can replace a breakdown and clean piece by piece