ISO Cleanroom Requirements & Cleanroom Classifications

From pharmaceuticals to aerospace, many industries today depend on cleanroom technology. These safe and contaminant-free spaces are ideal for conducting highly controlled research or manufacturing and packaging sensitive items.

If you plan on installing a cleanroom for the first time, the information associated with the process can be overwhelming – but we’re here to help. Our experts at Preferred Medical discuss the most common cleanroom classifications and what you can do to meet their requirements.

What Is a Cleanroom?

A cleanroom is a specially designed space where airborne contaminants are limited or completely removed using highly sophisticated filtration technologies and rigorous practices. Many industries invest in cleanrooms when their operational success relies on a highly controlled and monitored environment.

For a space to officially earn a cleanroom classification, it needs to meet a specific set of international standards and specifications regarding the number of microns per cubic foot (the particle concentration in a cubic foot of air).

How Do Cleanrooms Work?

Cleanrooms generally rely on these three components to maintain their effectiveness:

Air filtration: An HVAC system outfitted with air filters can block small particles and clean the air. Some popular filter options include ULPA and HEPA filters with an airlock system for maximum protection.

Quality construction: The materials used to construct a cleanroom space should not emit particles, chemicals, gases, and other contaminants. Their surfaces should also be straightforward to clean and maintain.

Personnel practices: Many cleanrooms come equipped with a separate gowning room where operators, workers, and staff put on gloves, gowns, beard covers, and other garments to minimize the number of particles from the skin, hair, and personal clothing.

What Type of Cleanroom Do I Need?

How do you pick the right cleanroom that meets your needs? Here are a few factors that you might need to consider:

• Government regulations and industry standards
• Client requirements
• Ease of maintenance
• Restriction of access
• Particulates
• Microbial contaminants
• Temperature
• Humidity

Regardless of your industry, we recommend using the ISO standard as the basis for your cleanroom implementation.

ISO Classification and Hourly Air Change

The US General Service Administration’s standards, known as federal standard 209E or FED STD 209E, were once widely adopted by various industries for cleanroom requirements.

Today, though, we use the standards and specifications set by the International Standards Organization (ISO). This global accreditation body comprises a technical committee and separate working groups to maintain and improve its own set of standards.

ISO 14644 specifies the air-change rate required for varying levels of air cleanliness, a crucial measurement that gauges the effectiveness of your indoor air filtration process.

Particle Size Within a Cleanroom

Required air changes aside, another essential factor specified in ISO 14644 is particle size. Why is this so important? The majority of harmful particles in the air are three µm (microns) or less, so you generally want a cleanroom system that can lower the concentration of these contaminants.

Cleanroom Classifications

There are currently six main ISO cleanroom classifications, each with a different set of requirements.

ISO Class 8

Despite being the lowest classification of air cleanliness, ISO class 8 cleanrooms are about 5 to 10 times cleaner than your average office space. Its regulations include:

No more than 35, 200,000 at >0.5 µm particles micron per cubic meter

5 to 48 air changes per hour (ACH)

5% to 15% ceiling coverage

ISO Class 7

Also known as the “common clean” cleanroom classification, ISO 7 spaces are useful for any sensitive medical device, electronics manufacturing process, or pharmacy USP800 compounding rooms. Its requirements include:

Maximum of 352,000 >0.5 µm particles per cubic meter

60 to 90 ACH

15% to 20% ceiling coverage

ISO Class 6

ISO 6 is a “very clean” cleanroom classification that many industries use, including nanotechnology, biotechnology, and pharmaceuticals. To classify as ISO 6, a space needs to have:

Maximum of 35,200 >0.5 µm particles per cubic meter

150 to 240 ACH

25% to 40% ceiling coverage

ISO Class 5

ISO 5 is a “super clean” cleanroom classification commonly applied to pharmaceutical filling and semiconductor manufacturing spaces. ISO 5 cleanrooms require:

Maximum of 3,520 >0.5 µm particles per cubic meter

240 to 480 ACH

35% to 70% ceiling coverage

ISO Class 4

ISO 4 cleanrooms are stringently controlled spaces utilized mainly for semiconductor and nanotechnology production and control zones for biotechnology. Its specifications include:

Maximum of 352 >0.5 µm particles per cubic meter

300 to 540 ACH

50% to 90% ceiling coverage

ISO Class 3

Class 3 cleanrooms are the most comprehensive out of all ISO classes. These spaces utilize the latest technology and require a considerable investment to install and maintain. They require:

Maximum of 3,5 >0.5 µm particles per cubic meter

360 to 540 ACH

60% to 100% ceiling coverage

What Are the Sources of Contamination in a Cleanroom?

The primary sources of contamination you need to account for in your cleanroom installation are:

• The air entering the facility
• Equipment and materials used in the manufacturing process
• The personnel working in the facility

Did you know that skin shedding can quickly raise the particle counts in your clean zone environment? Other contaminants from personnel like hair, oils, saliva, and fibers also carry a potential risk, which is why protective clothing is a must.

A Guide To Gowning Procedures

If you want to safeguard your cleanroom from outdoor contaminants, you need to implement strict dress codes and procedures for your staff. Here is a standard aseptic gowning process used by many equipment manufacturers and medical professionals:

1. Wear a bouffant cap to cover hair and ears completely
2. Wear shoe covers that completely enclose footwear
3. Sanitize hands and dry them off
4. Wear a pair of sterile gloves without touching their outer portion
5. Sanitize gloves and repeat after every succeeding step
6. Wear a properly fitted hood
7. Wear a face mask
8. Wear a coverall without touching its outer portion
9. Wear a boot cover using the proper aseptic techniques
10. Wear and seal goggles properly
11. Wear a second pair of gloves that covers the first pair

ISO Cleanroom Frequently Asked Questions

What’s the difference between a “clean corridor” or a “dirty corridor”?

“Clean” and “dirty” corridors are the two main types of cleanroom layouts used by pharmaceutical manufacturers.

Clean corridors are an excellent choice for low moisture products like tablets or capsules that carry high-cross contamination risks because the corridors prevent air from seeping out of the cleanroom. Dirty corridors do the opposite by keeping air from entering the cleanroom, which works well for products prone to microbial contamination.

Which way should my cleanroom doors swing?

The air pressure changes each time someone opens the door to a cleanroom, which harms its effectiveness. We recommend installing doors that open into the room with higher pressure for convenience. One effective, albeit more expensive, option would be to install power-assisted doors.

Why are cleanrooms used to produce nanomaterials?

The micro and nanochips inside the many electronic devices we use today are highly sensitive. Even the smallest particles contaminating these components can render them ineffective, which is why many companies implement higher ISO cleanrooms specifications for their manufacturing facilities.

Which is the correct ISO guideline for environmental control zones?

Most industries follow the ISO 14644 guideline when developing their environmental control zone. There are nine cleanroom classes, with ISO 1 considered the cleanest and ISO 9 the dirtiest.

Preferred Medical is a full-line national distributor of medical supplies of all sorts including cleanroom supplies. We carry everything your cleanroom needs including gloves, cleaners, mats, masks, rollers, and so much more. If you’re interested in buying cleanroom supplies you can create an account on our website today or Contact Us to get started.