What a Cleanroom is & the Kind We Use— 30 / 07 / 2021
Welcome to our weekly blog! This week we are shifting completely from coating and going straight into cleanrooms. No not that kind! I’m talking about the precautions taken within a particular room to control outside particles from entering. Continue reading to learn some more.
The basics of a Clean Room
The rankings for cleanrooms ranges from ISO 1 – ISO 9, with ISO 9 being the “dirtiest” and ISO 1 being the “cleanest.” Although, neither is dirty, just to be clear. Now these classifications are assigned based on the maximum allowed particles in the air per a certain amount of cubic feet. The lower the ISO class the more strict the requirements become.
Like I said early, a typical cleanroom is designed to keep outside contaminants and particles to a minimum, based on that ISO class’s clean room standards. Once fully built and operational, an isolated cleanroom is free from outside particles and contamination. However, there are two things that can introduce particles and contamination into your cleanroom: people and processes.
To lower contamination, facilities can require workers to wear cleanroom clothing such as face masks, hair and beard coverings, and lab coats or other frocks to cover their daily clothing. In some cleanrooms, coveralls and even gloves can also be required. It reminds me of those CDA guys from Monster’s Inc. when there is the sock – code 2319 – on monster George Sanderson.
Cleanroom clothing should be made from non-woven fabrics to prevent contamination from shedding material fibers. While gloves are sterile and made from latex, nitrile or other synthetic materials.
Now depending on the industry and application requirements, other precautionary measures can be taken to control the particle count in the cleanroom. Heck, sticky mats might be placed outside of cleanroom entrance to remove dirt and other contaminants from shoes. A pass-thru cabinet fitted with filtration systems could be used to safely transfer products while limiting the number of people entering and exiting the room.
Cleanroom requirements vary widely based on the industry standards and the type of processes being performed.
Here are some common ISO 7 clean room requirements:
- Product pass throughs
- HEPA fan filters
- Heat welded vinyl or epoxy floors
- Gowning atrium
- Air locks
- Air conditioners
- Entrance and exit sticky mats
- Sealed lighting
- Bunny suit, booties, and hood requirements
- Stainless steel bench and hands free sink
We operate an ISO Class 7 Clean Room
An ISO 7 clean room is just that, a room. But this room utilizes a HEPA filtration systems to make sure there isn’t more than 10,000 particles per cubic foot. Class 10,000 cleanroom filtration systems must provide filter coverage of 15-25% and a minimum of 60 air changes per hour. And the standard air flow rate for an ISO 7 filtration system is 9-16 CFM per square foot.
Here’s the number breakdown, but first, you need to know that µm means micron:
>=0.5µm can’t have more than 352,000 particles
>= 1µm no more than 83,200 particles
>=5µm better not go above 2,930b particles
Fun fact for ya: Class 7 clean rooms were previously defined under US Federal Standard 209E but since 2001 have been defined under ISO 14644-1. Both are still regularly used as reference points though.