Understanding ISO Class

Particle Counters Help Ensure ISO Class Regulations Are Met

Cleanrooms are not all the same, various levels of air purity exist. This is what we mean by an ISO class. The International Standards Organization has divided cleanrooms into nine distinct levels of classification based on the amount of particles allowed per cubic meter. The lower your classification the less particles are permitted in the cleanroom.  

Particle count testing is essential in determining your ISO class
  • Up to 10 particles ≥ 0.1 micrometers 
  • Up to 100 particles ≥ 0.1 micrometers 
  • Up to 24 particles ≥ 0.2 micrometers 
  • Up to 10 particles ≥ 0.3 micrometers 
  • Up to 4 particles ≥ 0.5 micrometers 
  • Up to 1,000 particles ≥ 0.1 micrometers 
  • Up to 237 particles ≥ 0.2 micrometers 
  • Up to 102 particles ≥ 0.3 micrometers 
  • Up to 35 particles ≥ 0.5 micrometers 
  • Up to 8 particles ≥ 1 micrometer 
  • Up to 10,000 particles ≥ 0.1 micrometers 
  • Up to 2,370 particles ≥ 0.2 micrometers 
  • Up to 1,020 particles ≥ 0.3 micrometers 
  • Up to 352 particles ≥ 0.5 micrometers 
  • Up to 83 particles ≥ 1 micrometers 
  • Up to 100,000 particles ≥ 0.1 micrometers 
  • Up to 23,700 particles ≥ 0.2 micrometers 
  • Up to 10,200 particles ≥ 0.3 micrometers 
  • Up to 3,520 particles ≥ 0.5 micrometers 
  • Up to 832 particles ≥ 1 micrometer 
  • Up to 29 particles ≥ 5 micrometers 
  • Up to 1,000,000 particles ≥ 0.1 micrometers 
  • Up to 237,000 particles ≥ 0.2 micrometers 
  • Up to 102,000 particles ≥ 0.3 micrometers 
  • Up to 35,200 particles ≥ 0.5 micrometers 
  • Up to 8,320 particles ≥ 1 micrometer 
  • Up to 293 particles ≥ 5 micrometers 
  • Up to 352,000 particles ≥ 0.5 micrometers 
  • Up to 83,200 particles ≥ 1 micrometer 
  • Up to 2,930 particles ≥ 5 micrometers 
  • Up to 3,520,000 particles ≥ 0.5 micrometers 
  • Up to 832,000 particles ≥ 1 micrometer 
  • Up to 29,300 particles ≥ 5 micrometers 
  • Up to 35,200,000 particles ≥ 0.5 micrometers 
  • Up to 8,320,000 particles ≥ 1 micrometers 
  • Up to 293,000 particles ≥ 5 micrometers 


Particle Size Matters 

As seen above the size of particles matter. Significantly more 0.5 micrometer particles are allowed than 5 micrometer ones. As such it’s important to know the size of particles when determining the standard of cleanroom that you need constructed.  

If you wanted a cleanroom with a maximum of 100 particles per square meter you would need a lower classification for particle of 0.5 micrometers compared to 5 micrometer particles.  

What ISO Classes Mean for You 

More than anything your purpose is what determines the ISO class you choose.  Different industries have different classes they default to. Ultimately it all depends on permissible particle count, particle size and required air circulation. 

When an ISO class is settled on, there is more to keep in mind though.  For example, cleanrooms of ISO level 7 or lower should include a changing atrium. This helps prevent contamination being brought into the cleanroom by personnel entering. 

ISO class is also going to affect testing your cleanroom. Due to the lower maximum particle counts ISO class 5 and lower need to be tested every six months, while 6 and higher need to be tested yearly.  

Similarly, your ISO class will determine cleaning processes. Knowing how to properly maintain your cleanroom is vital to ensure compliance to ISO guidelines.  As you might expect ISO class 1 cleanrooms require a very thorough process to maintain compliance when compared to higher levels.  

Modular Cleanroom Vs. Traditional Construction

If you’re setting up or expanding a facility, or even if you’re just starting a new project, you may need a cleanroom. When you’re looking at what’s available it’s easy to get lost in the pros and cons of modular and traditional cleanrooms. So, we thought it would be a good idea to put together a quick comparison guide to get you started on the decision.

Whether you choose to have a modular cleanroom or traditional construction is going to come down to a number of factors. The size of your operation, time constraints, your budget and more all play a part. So, if you’re still not sure after reading this then just get in touch and speak to one of our experts and we’ll talk you through everything.

Scale of Modular and Traditional Cleanrooms

Generally, modular cleanrooms are great for any size. Due to the nature of construction, they can work for compact cleanroom- like the one we constructed for the EIRSAT-1 team– or larger cleanrooms. Since the cleanroom is made of a series of panels there is no upper limit to sizing beyond the physical constraints of where is it constructed.

Where modular cleanrooms really stand out though is with expansion. When you are working with a traditionally constructed cleanroom you will find it difficult to expand. It will require serious renovations, potentially new ducting and a lot of time, for which your cleanroom will be non-operational. However, with a modular cleanroom expansion it is as simple as slotting in new panels. This lets you reduce construction time and have an operational cleanroom significantly quicker.

Installation Time Of Modular Cleanroom VS. Traditional Construction

We touched on this above but modular cleanrooms are much quicker to install. With traditionally constructed cleanrooms a build could potentially take months. Raw material needs to be sourced and the room built on site. All of this takes time. In the best case scenario that’s time where you could be operational and slowing down, your work. In the worst case scenario, you don’t meet time constraints.

When you choose to go with a modular construction this is less of a problem. Since they are made up of individual panels construction time is minimised. We simply need to bring the right number of panels and slot them together. Depending on the size of the build this could be done in just days.

The simpler construction also means relying on less people. Our team of engineers can fully construct a cleanroom using a modular construction. A traditionally constructed cleanroom would require multiple tradespeople. By streamlining the construction process, we can estimate the completion time much more accurately than traditional constructions.

Modular Cleamroom installation timeline

No Need for HVAC in Modular Cleanrooms

One of the major benefits of using modular cleanrooms is that they don’t need a HVAC system to function. Traditional cleanroom constructions require HVAC systems, that means they pull outside air into the cleanroom through filters. They also filter air out of the cleanroom.

This does a great job at purifying the air, but it is also a time consuming and costly addition to a build. More importantly though, a complex system of filters, fans, ducting and pumps leaves more room for failures. Even if nothing goes wrong you will still need to routinely replace equipment to keep your cleanroom at optimum efficiency.

Modular cleanrooms on the other hand work by filtering air through a clean air module. This more compact and streamlined method means the air in the cleanroom is being recirculated instead of being pulled in from outside. CAM’s offers fewer points of failure than HVAC systems and significantly easier maintenance.

Longevity Of Modular Cleanrooms

You might assume that due to the way they’re constructed modular cleanrooms don’t last as long as traditional cleanrooms. In fact, modular cleanrooms have one advantage in this area. They don’t shed.

The materials used to create a traditional cleanroom shed over time. This decreases the air purity and can introduce pollutants into the clean room. This can be due to drywall, paint, etc. When using a modular cleanroom, they are typically constructed from high grade aluminum. As a result, modular cleanrooms will not shed keeping air purity higher without maintenance for longer.

Cost Difference Between Modular Cleanrooms & Traditional Construction

All of this put together means that modular cleanrooms run at a much lower cost than traditional cleanrooms. This is true for the up-front costs of the cleanroom and of the money spent on labour. With less raw material and fewer tradesmen needed to set up your cleanroom from the beginning.

Even after construction has been completed modular cleanrooms can cycle air much more efficiently without an HVAC system. Lowering the energy costs required to keep the cleanroom operational.

When it comes to the time for preventative maintenance and emergency repairs, you’ll still get the benefits of lower costs. Whether it’s swapping the filter out of a clean air module or replacing a damaged panel it can all be done quickly and cheaply.

Modular Cleanroom

Which is best?

For most applications a modular cleanroom is a very good choice. This is why industries have been moving away from traditionally built cleanrooms and towards modular and pod based cleanrooms in recent years.

The benefits offered by modular designs are hard to beat, and as technology improves. Those improvements also become very easy to implement with modular designs.

Whether you’re planning for expansions, need construction completed quickly or just want to keep the budget down, modular cleanrooms are worth considering.