Sanitation, Cleaning and Hygienic Design of Equipment
What the exam tests
Cleaning chemistry and mechanics, CIP and COP, sanitizer use, verification, and hygienic design that makes cleaning possible.
Core rules
- Cleaning removes soil; sanitizing reduces microorganisms on a clean surface. Sanitizer on soil is wasted.
- TACT: time, action, concentration, temperature. CIP also needs velocity (often 1.5-2 m/s) and correct circuit geometry.
- Hygienic design: smooth, crevice-free, drainable, radiused corners, no dead legs or threaded food-contact parts, 316L stainless where needed, welded and polished.
- Verify cleaning with ATP, protein, allergen swabs, and visual inspection; verify sanitizer concentration with test strips or titration.
- Dry cleaning is preferred in dry environments to avoid creating microbial growth niches.
Worked example
A CIP return line has a 1.5 m dead leg. Post-CIP ATP swabs at the dead-leg outlet read 350 RLU versus a limit of 150. Root cause: low flow and no turbulence in the branch. Corrective action: remove the dead leg or add a controlled flush, re-clean, re-swab, and trend. Releasing product before verification is a traceability failure.
Traps
Topping up sanitizer without measuring; using a quat on a dirty surface; assuming stainless is self-cleaning; ignoring condensate; cleaning only the product contact surface and not the equipment frame.