Getting a head start on food safety by beginning with hygienic and sanitary design
This informal CPD article on Getting a head start on food safety by beginning with hygienic and sanitary design was provided by Diversey, who offer training courses for food and beverage processing professionals.
Food safety begins with hygienic and sanitary design. The mechanical construction of the processing equipment, the materials used and the layout of the production floor all play an important and significant role in achieving food safety. Inspections and preventative and corrective maintenance should be carried out routinely to ensure compliance over time and should follow the main aspects below.
1 – Identify risks
Risks can be categorized as:
- Physical hazards: foreign bodies from the equipment such as plastic pieces and glass particles.
- Biological hazards: the main food pathogens (Salmonella, Listeria, Campylobacter and E coli), pests and microbiology.
- Chemical hazards: residues from the cleaning chemistry.
Food safety risks are present across the entire production process and production plant and do not only apply to the direct food contact surfaces; non-product contact surfaces, people, vents and drains harbor food safety risks.
2 – Are surfaces cleanable to a microbial/allergen free level?
Processing equipment and food-contact surfaces must be constructed in such a way that enables effective and efficient cleaning for the full lifespan of the equipment. Surfaces should be designed in such a way to avoid any allergens or foodstuffs remaining after cleaning and prevent bacterial ingress, survival, growth and reproduction.
Equipment that has become damaged over time can usually be recovered by re-surfacing and treatments such as grinding, polishing and passivation can be used to improve cleanability.
3 – Use materials that are suitable for food and beverage processing
Materials used for the manufacture of food processing equipment must be completely compatible with the product(s) being made, the production environment, cleaning and disinfecting chemicals and the methods of cleaning. Materials should have non-painted surfaces to prevent foreign body contamination and should not contain any substances capable of tainting food.
4 – Is there adequate drainage?
The interior and exterior of all equipment should be self-draining to avoid pooling or condensation of any liquid which can harbor and promote the growth of bacteria
5 – Can all equipment be cleaned, inspected and maintained?
All parts of the equipment need to be readily accessible for inspection, maintenance, cleaning and disinfection without the use of tools. Equipment being cleaned by CIP (cleaning-in-place) should be following a validated process which is re-validated after any changes such as product recipes or equipment upgrades.
Maintenance enclosures, push buttons, handles etc must be hygienically designed and should be sloped or pitched to avoid being used as a storage/shelving area.
6 – Ensure all materials are correctly sealed or properly welded
Continuous welding is the preferred technique for the fabrication of stainless steel components. All welds should be inspected internally by an endoscope or x-ray if necessary.
7 – Identify and manage crevices and dead legs
A process pipework dead leg is any “T” piece where the tee pipe length is more than half a pipe diameter in the “non-flow” direction or 1 pipe diameter in the “flow” direction. If the dead leg exceeds these dimensions there will not be sufficient CIP mechanical action in the dead leg to remove soiling and the disinfectant may not be able to contact the surfaces during the disinfection step, causing contamination of the next product processed.
If the dead legs are excessively long or configured downwards, then they may remain full of “stagnant” product.
8 – Avoid hollow bodies
Hollow areas of equipment such as frames and rollers must be eliminated wherever possible or permanently sealed. Bolts, studs, mounting plates, brackets, junction boxes, nameplates, end caps, sleeves and other such items must be continuously welded to the surface not attached via drilled and tapped holes.
9 – Identify all cross-contamination vectors
Machinery must be so designed and constructed that no ancillary substances (e.g. lubricants, etc.) can come into contact with foodstuffs. They have to be resistant to cracking, chipping, flaking and abrasion.
Open containers should be shielded.
The following building construction and zoning principles should be understood and implemented:
- The design and layout of workspaces allowing for one-direction production flow
- Sufficient lighting especially in food preparation and inspection areas to aid visual inspections during manual cleaning
- Suitable employee facilities such as non-touch hand-washing systems, door-fogging and break areas
- The materials and design of external and interior construction of walls, floors, doors.
- Physical separation of activities to prevent cross-contamination with allergens or biological hazards such as harmful microorganisms from raw to cooked food.
10 – Document all cleaning processes, inspections and validation projects
Procedures for cleaning and disinfection must be clearly written, designed and validated to be effective and efficient. Chemicals recommended for cleaning and disinfection must be compatible with the equipment and the manufacturing environment.
We hope this article was helpful. For more information from Diversey, please visit their CPD Member Directory page. Alternatively please visit the CPD Industry Hubs for more CPD articles, courses and events relevant to your Continuing Professional Development requirements.