We all know what a clean room looks like, but have you ever experienced a ‘cleanroom’? A cleanroom is an environment you might have come across in a hospital or a manufacturing plant, a room that is free from the sorts of contaminants that exist in regular spaces, such as dust, airborne microbes, aerosol particles and pollen.
Cleanrooms are the sorts of places you see in movies such as Outbreak, where virologists work with dangerous diseases like Ebola. They are specially designed to be airtight and use filters to keep out the sorts of particles that are surrounding you right now as you read this. They take ‘clean’ to a whole new level.
How are cleanrooms designed?
The air in a typical city contains about 35,000,000 microscopic particles per cubic metre. Some manufacturing processes require these particles to be removed from the room. All of them. There various grades of cleanroom, but an ISO 1 cleanroom must be free of all 35,000,000 particles. Now that’s a clean room!
To achieve this, a cleanroom has a High Efficiency Particulate Air (HEPA) filter. It also has temperature, pressure and air flow controls. Air flow is directed to keep particles that escape the filter or are carried in by workers close to the ground. In many cleanrooms, air enters through the ceiling and is directed down, to return to the filter through vents near the floor. The typical office air-conditioner, where both the output and intake vents are mounted in the ceiling, would not comply with cleanroom standards. Special mops and buckets are used, and objects that shed themselves (like pencils or erasers) are excluded.
Which industries use cleanrooms and why?
According to an article in Wired, a single dust particle from your hair can destroy a CPU that costs $500. Cleanrooms make it possible to print the micro-circuits that have driven the digital revolution. Pharmaceutical cleanrooms are used to develop vaccines and drugs that are easily contaminated. Scientists who work in them must wear protective clothing to stop contaminants like hair and skin particles entering the manufacturing process.
Commercial cleaning in hospitals
You may never enter a cleanroom, or even see one, but a visit to a hospital or medical centre gives you an idea of the standards required. Commercial cleanersuse strong disinfectants such as QUAT-4, powerful enough to kill HIV as well as Staphylococcus, E. coli, Hepatitis B and other bugs. Vacuum cleaners are equipped with HEPA-grade filters, and cross-contamination is avoided by using colour-coded mops and wipes and changing them frequently.
Cleanrooms certainly give new meaning to the word ‘clean’. They are vital to things we use every day. For example, the camera lens on your phone and the aspirin you take were likely both manufactured inside these amazing spaces.