Basic Cleanroom Wipedown

The housekeeping practices recommended here provide a comprehensive program for the removal of contamination. It should be recognized that not all these practices are necessary for all cleanrooms. In general, cleaning should begin in the areas requiring the most critical level of cleanliness and proceed toward less critical areas. Little Brothers Construction recommends using a cleaning agent comprised of 10% alcohol and 90% de-ionized water.

Ceilings: Ceilings consisting of surfaces other than HEPA filters should be vacuumed and wiped with a cleanroom wiper or mop lightly wetted with a cleaning agent. Cleaning should be performed in a single-line fashion. Circular and scrubbing motions should not be used.

Light fixtures: Light fixtures should be wiped with a cleanroom wiper moistened with a compatible cleaning agent (to prevent etching the lens). The inside of the lens should be cleaned in a similar manner.

Walls: Walls should be cleaned beginning at the ceiling and working in vertical lines toward the floor. First, the walls should be cleaned with a vacuum apparatus using overlapping strokes, followed by wiping or damp mopping. The wipers or mop should be lightly wetted with a cleaning agent. Rinsing may be required, depending upon the type of wipe used, dirt accumulated, and the cleaning agent.

Windows: Windows should be cleaned using a wiper wet with a suitable cleaning agent. Wiping should be in a vertical motion (top to bottom) to moisten the windows. After each stroke, the wiper should be folded to expose an unused portion. In a non-aseptic environment, a dry wiper or squeegee should be used to dry the window in a top-to-bottom manner, as described previously.

Plexiglass: The Number 1 problem with plexiglass is the use of incorrect cleaners. Never use cleaners containing ammonia. Cleaners such as Windex or 409 will harm the plexiglass permanently. Use only products specifically recommended for cleaning plexiglass such as Formula 509, Novus #1, or Brillianize, and a soft cloth. Never use a dry cloth or your hand to clean the plexiglass! This rubs the dirt and dust into the plexiglass as much as it rubs it off. First, blow the dust or dirt off, or use water and a soft cloth to float the dirt off. Then use a recommended cleaner to complete the job. Note: a mild solution of dish detergent and warm water takes off stubborn dirt easily without harming the plexiglass if you don’t have a recommended cleaner.

Door/Frame: First, the top and side edges of the doors should be cleaned while they are ajar, using the appropriate vacuum tool, followed by wiping. The wiper should be moistened with a cleaning agent and the surface rinsed if required by the cleaning agent. Doors and associated surfaces should be cleaned by following the procedure outlined for walls.

Floor: The entire floor should first be vacuumed or mopped with a tacky mop, using the following procedure:

The vacuum attachment or mop roller should be placed on the floor, pulled toward the operator, then lifted and moved, so that the next stroke starts adjacent to and slightly overlapping the first stroke. The floor should then be damp mopped with a cleaning agent, using a series of slightly overlapping strokes. Rinsing may be required, depending on the type of cleaning agent used.