Looking for some advice on best methods of cleaning underneath equipment.
We have two machines that are on either side of a trough drain. We swab (APC, internal and external lab testing) the undersides of these machines whenever the drain swabs are non-conforming as part of our environmental monitoring plan. The undersides of the machines are about 5 inches off the ground. We have been able to get the drain back into specification through intensified cleaning, but for the past few weeks, the undersides of the machines have been bouncing back and forth between conforming and non-conforming. Our intensified cleaning for the undersides of the machines have been scrubbing (with a brush dedicated to these machines) with a chlorinated detergent and sanitizing by applying a layer of peracetic acid with foam additive very thickly on the floor under the machines such that the foam reaches the undersides of the machines.
Even with these actions, we have been going back and forth between conforming and non-conforming. These are the same corrective actions taken for bringing the drains back into specification and they have continuously worked well for the drains in all our production areas.
We have tested the inside of the machines as well as we believed that there may be a chance that there is some way the contamination could be coming from there, but it was determined that this was not the case. We have also ensured that product is not being poured out onto the floor in this production room, which could potentially introduce some splashing of the product up onto the underside of the machine.
Any advice would be greatly appreciated, including advice regarding general cleaning of undersides of machines.