Internal Plant Building Design for Food Safety

By PMG Engineering · 21 Jun 2019

Outdated and classic methods are still commonly used by many food manufacturers to control food safety. However, hygienic design of food processing equipment and factories is known to significantly enhance food safety. In this article, we will explore key design considerations that improve food safety in food manufacturing facilities.

Key Objectives of Sanitary Interior Design in Food Factories

The primary sanitary objectives for interior building design and construction are to:

Minimize potential harborages of pests and microorganisms
Maximize cleanability
Protect food products from contamination

To achieve these objectives, facilities must be designed to ensure a smooth flow of materials, personnel, and equipment, preventing contact between raw and finished products. The flow pattern should ideally be one-directional and logical, from raw material handling to finished product storage.

1. Interior Walls: Ensuring Cleanability and Hygiene

A cleanable, sanitary wall is one that is hard, flat, and smooth, free from pits, cracks, and crevices. Walls should be coated with light-colored paint and caulked, sealed, or grouted properly at junctions. To improve cleaning, junctures between walls, ceilings, and floors should be rounded with a radius of one inch or greater, minimizing hard-to-clean crevices.

2. Ceilings: Preventing Overhead Contamination

Improper ceiling installation, condensation issues, or poorly maintained ceilings can lead to contamination. The recommended installation is concrete slab construction, with smooth finishes and caulking at joints. Dropped ceilings are acceptable only if installed correctly, and false ceilings should be avoided to reduce contamination risks.

3. Floors: Durability and Safety

Floors must be smooth, impervious, non-absorbent, corrosion-resistant, and easy to clean. They should also be slip-resistant to prevent employee accidents. Ideal materials include sealed concrete, epoxy-sealed concrete, quarry tile, and glazed tile. Unsealed concrete should be avoided as it is porous and deteriorates over time.

4. Drains: Ensuring Efficient Wastewater Management

Floor drains should be of adequate size and strategically placed for proper cleaning. Circular, catch basket drains are most recommended, provided they are sealed and maintained correctly. Trench drains should be constructed to provide proper slope, ensuring no standing water.

5. Interior Lighting: Safe and Sanitary

Lighting in food facilities must adhere to sanitary standards, with light fixtures that have break-resistant lenses or shatterproof shielding. These fixtures should also be moisture-resistant and easy to clean.

6. HVAC Systems: Maintaining Clean Airflow

HVAC systems are crucial for controlling temperature and humidity, but they must be properly designed, installed, and maintained to prevent contamination. The air supply should be strategically located, away from sources of contamination like chemicals or bird droppings. Filters and ductwork should be designed to minimize contamination risks.

7. Employee Facilities: Maintaining Separation from Processing Areas

Employee facilities such as locker rooms and restrooms should not open directly into critical processing areas. Most regulations require a two-door separation between such areas and the food production zones. Lockers should be sealed to the wall, with sloped tops to prevent dust accumulation.

8. Physical Separation Between Raw and Finished Products

To minimize contamination risks, it is crucial to have a physical separation between raw and finished products. This can be achieved by installing walls and doorways with anti-backtracking features and adjusting air handling systems to provide positive pressure in finished product rooms. Proper personnel flow is also essential, barring those working with raw materials from entering finished product rooms.

Conclusion: Integrated Features for Food Safety

A sanitary food processing and handling facility must be designed with integrated features to protect products from contamination. Regular inspections and maintenance schedules are essential to ensure food safety and cleanliness. Proper sealing of utility lines and cleaning protocols also play a significant role in maintaining hygiene.

Frequently asked

What flow pattern should we adopt inside a food processing building to avoid cross-contamination?

A food factory interior should be designed for a smooth flow of materials, personnel and equipment that prevents contact between raw and finished products. The flow pattern should ideally be one-directional and logical, moving from raw material handling through to finished product storage. This layout discipline supports the three sanitary objectives: minimising harborages for pests and microorganisms, maximising cleanability, and protecting product from contamination.

What makes an interior wall cleanable in a food plant?

A cleanable, sanitary wall in a food facility is hard, flat and smooth, free from pits, cracks and crevices. Walls should be coated with light-coloured paint and properly caulked, sealed or grouted at junctions. To make cleaning easier, junctures between walls, ceilings and floors should be rounded with a radius of one inch or greater so that hard-to-clean crevices are eliminated.

Are false ceilings acceptable over a processing hall?

False ceilings should be avoided in food processing areas because they increase contamination risk. The recommended installation is concrete slab construction with smooth finishes and caulking at joints. Dropped ceilings are acceptable only if they are installed correctly. Improper ceiling installation, condensation problems or poorly maintained ceilings are all recognised routes to overhead product contamination.

Which floor finishes do you recommend for food processing areas, and what should we avoid?

Food processing floors must be smooth, impervious, non-absorbent, corrosion-resistant, easy to clean and slip-resistant to prevent employee accidents. Suitable materials include sealed concrete, epoxy-sealed concrete, quarry tile and glazed tile. Unsealed concrete should be avoided because it is porous and deteriorates over time, creating harborage points and cleaning difficulties.

What type of floor drain works best in a food factory, and how should trench drains be built?

Floor drains in food facilities should be adequately sized and strategically placed so the area can be cleaned properly. Circular catch basket drains are the most recommended option, provided they are correctly sealed and maintained. Where trench drains are used, they must be constructed with proper slope so that no standing water remains in the processing area.

How should employee locker rooms and restrooms be positioned relative to processing areas?

Locker rooms and restrooms should never open directly into critical processing areas. Most regulations require a two-door separation between these employee facilities and food production zones. Lockers themselves should be sealed to the wall and fitted with sloped tops so dust cannot accumulate on them, keeping the changing area cleanable and reducing contamination carried into production.

CITE THIS

PMG Engineering. (2019). Internal Plant Building Design for Food Safety. PMG Engineering. https://pmg.engineering/Article/11/internal-plant-building-design-for-food-safety/

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