Process and Operations / Food Safety

MRO Q&A: Building Inside the Building

A reader asks what things he should watch out for during a still-operational expansion project.

Q. We are in the design phase of a capacity-expansion project, which will require major modifications to our food manufacturing facility. The plant will need to be kept operational during this process. Can you suggest any “watch outs” that I should be aware of during the project?

A. Adding more capacity is always exciting, as it is the true sign of growth. Good for you! Depending upon your current situation, the most flexible approach is to build “a building inside your building.” Your primary concern should be food safety in the existing operational area. There are four major areas you should address before the modifications commence: traffic flow, air pressure, sewer seals and contractor education of good manufacturing practices (GMPs).

The first consideration will be to assess existing traffic patterns for people and equipment. These flows may not be intuitive, so get the employees from the various areas (shipping, warehousing, maintenance and utilities) involved to determine current and proposed traffic changes. You likely will find that some existing doorways will have to be temporarily eliminated and new ones created. You may also find that some doors will have to be controlled. An example of this would be the need to supply material for the next day's production during the prior midnight shift. During normal production, the door would be locked, then unlocked and opened during the replenishment period.

Keep in mind the traffic flow of the construction workers. They typically would not be garbed in food processing attire, so they will require separate entrances and exits. Construction workers also may require separate rest areas and toilet facilities.

The next area of concern is air pressure. In a typical food production facility, positive air pressure is desirable in all production, warehousing and shipping areas. This inhibits external pollen and other airborne particles from entering the plant. In the case of a construction area, you will want negative pressure to keep any dust, particulate or other contaminants from migrating toward the production area. Depending upon the amount of concrete destruction to be done, exhaust fans and temporary ducting might be advisable. It also would be wise to check to make sure that the make-up air for operational areas is not coming from the area to be modified.

Although not always obvious, you should consider where your existing floor drains will connect to the newly modified area. Ideally, the new drains would be independent of the existing drainage system, but that is not always practical. Checking to make sure you have a sufficient water seal in your drains’ P traps and that they are in good repair is a good practice. What you are trying to avoid is the ingress of odors from chemicals used to etch floors or the pungent odor of elastomeric sealers used in construction.

The people side of the project is about rules of conduct for contractors when they are inside the facility. If you are able to totally isolate contractor personnel from the production workforce, this is not a concern. But if there is any overlap in areas of usage, the rules need to be the same for all. Construction workers, unless they frequently are involved in food projects, are not aware of GMP requirements and will often need frequent reminders of the rules.

Now that you have these four areas of concern addressed you are ready to construct the “building.” After determining the common walls between your existing area and the area to be modified, a framed structure should be built to enclose the area being modified. As a general rule, wood is frowned upon inside food manufacturing facilities, but in this case, because these structures are temporary, it is allowed. Isolating the ceilings of the two areas with wall partitions usually is quite difficult because of conduit and utility piping. As an alternative, a temporary ceiling can be constructed with plastic to allow available light to shine through. The last step in securing the construction area is to seal the floor to the walls, the walls to the adjoining walls, and the walls to ceiling joists to prevent any construction particulates from entering the operations area.

Following these guidelines should help you avert several common problems that occur when modifying an area in a food plant while maintaining production in an adjacent area. Good luck with your exciting project!