My company just built a Class 10,000 or ISO Class 7 cleanroom. We are trying to figure everything out. Right now the room isn't used very often but we are still cleaning it once a week. Is that too much? Everything I have read or been told says that humans are the biggest cause of particles in the cleanroom, so wouldn't I be creating more particles that I would be getting rid of?

Also, If we had a power outage would we need to have it re-tested for ISO?

People and the process are the primary particle generators in a CR.

You should conduct the particle count testing baselines, and establish partcle count standards, this will determine the cleaning thoroughness / frequency.

Are the HEPAs being run continuously?

When setting up a cleaning schedule, you should consider the fact that horizontal surfaces will become dirtier more quickly than vertical surfaces. Also, the surfaces that come into contact with people or process will become dirtier than those that do not. This means that wall and ceiling do not collect as many particles and require less cleaning than floor and doors. Door or floor will need more cleaning thanwalls because they are touched/stepped more often.

Besdie that, you should consider separating the cleaning area as "critical", "general" and "outside".

The "critical" area is the production zone where contamination can gain direct access to the product. These critical areas should be cleaned to the highest level, both the method and frequency.

The "general" area is where contamination cannot directly contaminate the product, but it can transferred to "critical" areas. e.g. walls and floors. The cleaning can be less stringent.

The "outside" area is the area like air lock, clothes changing and other ancillary areas. The cleaning method here can be less strict, although because of extra activity it may be necessary to do it more frequently.

After the power outage, you should verify the room pressure and retest the particle count in cleanroom, you may not need to run a full sampling test if the outage is short. Beside the, the temperature and humidity should be check. You should write out the cleanroom power down procedure on both "Planned" and "Unplanned" condition.

In summary, to start up a new clean room, you should establish a cleanroom control protocol/procedure which covers all the aspects…e.g.
– People control and behavior (CR attire and chaning frequency, gowning/degowning method, prohibited material, make up, do and don't, etc..)
– Personnel and Parts entrance and exit procedure
– Equipment and Maintenance control
– Cleanromm monitoring (particle count, pressurization, temperature, humidity and air velocity)
– Cleanroom power down reaction plan
– Cleaning protocol (method, tools and frequency)
– Emergency Evacuation
– Cleanroom audit plan
– Cleanroom awareness training and certification

We do have most of those written. Its all based off of what I have researched and what the customer wanted. Right now we have it written as is is fully cleaned once a week whether in use or not.

As of right now I am the only one who goes in there and its a tiny room, we put a max of 4 people in the room.

The HEPA filters do run all the time, and there is nothing going on in there and nobody going in there.

After talking to some people I was starting to feel like maybe a full cleaning while not in use was excessive. Then it tested EXTREMLY low when we had it tested. It isn't worth it for us to buy a particle counter for how small the room is and with the customer only wanting it tested quarterly. When it is in use we are cleaning the door and the floor daily along with work surfaces and any other critical areas.

Reading only helps so much. How often should I be cleaning it while its not being used?

If your cleanroom is not in use for long period or frequently, I think you can choose to prolong the cleaning schedule.

More importantly is that there should be a thorough cleaning before resume the production.