The basic rule of thumb for cleaning and environmental control in a dry- or low-moisture plant environment is quite simple: if the environment is dry, keep it dry. The reality found in most plant environments, however, is not that simple. More often than not, it requires special considerations, including the review of current practices to help minimize water usage in dry areas, traffic flow studies to help minimize migration of people and plant equipment (such as forklifts) from wet to dry areas, and employee compliance with Good Manufacturing Practices (GMPs). If any moisture is either introduced into or forms in a dry area at any time, having a method that quickly and thoroughly removes/dries this moisture is an absolute necessity.

Microorganisms, including pathogens, do not have the ability to move on their own. Once inside a plant environment, microorganisms will migrate throughout the plant and find their way to areas favorable for growth. Areas that have shown to be potential problems for microbial or pathogenic growth include the following:

•    Cracks and crevices on floors, walls and production equipment
•    Hollow framework on equipment and rollers, and wet or rusting framework
•    On/off switches and rubber seals around doors
•    Compressed air and poorly maintained air filters
•    Trash areas
•    Condensate
•    Maintenance tools
•    Cleaning aids, such as sponges, brushes and green pads
•    Damp insulation
•    Drains backing up in production areas
•    Product changeovers on processing or packaging lines
•    Production lines that have been moved or modified significantly

However, there are simple steps you can take to protect your operation from contamination.

Step 1: Review Current Practices
During production, eliminate use of water hoses. Monitor and question all uses of water in dry areas.

Eliminate water draining to the floor and drain directly to the floor drain. In areas where a dry floor cannot be maintained, use an EPA-registered solid or powdered quaternary sanitizer to help reduce potential bacteria levels as directed by the product label. Clean and sanitize drains daily.

All hoses, hose nozzles, parts and equipment should be stored off the floor and catwalks. If any in a dry area are found leaking, the leaks must be repaired immediately. There is a potential for employees to contaminate themselves by picking up items from the floor. Employees can then potentially touch food contact surfaces.  

Any food product that hits the floor is considered garbage—shovel, sweep or squeegee away. Do not use water during production.

Control condensate. Check and clean drip pans and drain lines from air conditioners or dehumidifiers. Use a solid, time-released, EPA-registered sanitizer in drip pans as directed by the product label. Do not drain condensate lines onto the processing area floor. Condensate lines should be hard plumbed to a drain. Shield condensate from dripping onto processing or packaging equipment.

Remove all old equipment from an area if it is not in use, as stored equipment can be a microbial harborage area.  

Maintain all pipe insulation in sealed, cleanable condition.

Control of environmental conditions helps reduce possible microbial contamination sources. Investigate and repair all leaks immediately—water and sanitizer hoses, roof leaks, and pipe and steam leaks. A routine monitoring and maintenance program should help identify and eliminate sources of water or moisture to maintain a dry environment. In addition, all air flow into the plant should be filtered, and all doors should be kept closed.  Critical processing rooms should be under slight positive pressure.

Use an EPA-registered food contact sanitizing wipe or alcohol-based sanitizer during production for spot sanitizing of hard, non-porous, food-contact processing surfaces or tools as directed by the product label.

Maintain a robust pest elimination program.

Step 2: Review Traffic Flow Patterns
The goal is to limit movement of people and plant equipment, such as forklifts, to limit potential for cross contamination in the environment. Many older plants have issues with plant layout, which further limits control of traffic and products. Initiate a traffic flow study with team members that include operations, quality and sanitation personnel. Analyze the following:

A. Is there complete separation of raw and cooked products? Raw materials that are at a higher risk for introducing pathogen contamination include raw eggs, milk, meat and poultry. Physically isolate the receiving area from the rest of the plant with no direct openings into processing areas. Control foot and fork lift traffic. If possible, color code uniforms of raw and processed area personnel, and assure that clean uniforms and footwear be worn.

B. Determine which areas can remain dry, and which areas will have wet activities.  Isolate those areas to limit employee movement, and dedicate employees, tools, parts and forklifts for those areas. Identify traffic patterns in and out of each line to determine how supplies are moved and isolate each so that routes are established for dry and wet ingredients. Employees must be trained to observe these routes. For employees and supplies that cannot be isolated, consider creating a transitional or staging area where either wheels and footwear can be sanitized and dried quickly and thoroughly or employees can transfer supplies for movement between areas.

C. Eliminate access to the plant from the roof.

D. Maintain and routinely clean forklifts and other equipment moving through the plant, such as product containers, bins and totes, etc.

E. Maintain clean, dry traffic hallways.

Step 3: Train Employees and Enforce GMP Compliance
Employees must be trained on personnel hygiene and GMPs, and compliance must be enforced. They need to understand their impact on the quality and safety of finished products, and the possible consequences of non-compliance.  

Employees should be required to wash and sanitize their hands before entering any area of the plant. Hand wash areas should be located outside the processing area to prevent transfer of any moisture into the processing or packaging areas. Hand sanitizing stations should be placed in all product contact areas—hands may be sanitized without adding water into dry areas by using alcohol-based hand sanitizer. No-touch dispensing systems will further help reduce potential for cross-contamination.

In addition, all boots or shoes should be dry when entering into dry processing or packaging areas. Boots should be scrubbed and sanitized with an EPA-registered sanitizer as directed by the product label at shift end and allowed to dry before next shift, or be scrubbed and dry before entering the processing area. Automatic doorway sanitizing systems will help protect key traffic areas.

In summary, environmental monitoring and control, limiting or eliminating employee and plant equipment movement from wet to dry areas and good personnel hygiene practices can go a long way to help control and prevent growth of microorganisms or pathogenic bacteria in a dry or low moisture processing environment. Choose a reputable and knowledgeable sanitation supplier and pest elimination provider to assist with developing an effective and efficient sanitation program and procedures customized for your operation.