What is ISO 5 equivalent grade?

ISO 5, also known as Class 100, is a cleanroom classification standard defined by the International Organization for Standardization (ISO). It specifies the maximum number of particles of a certain size that are permitted per cubic meter of air in a cleanroom environment.

What does ISO 5 equivalent grade mean?

ISO 5 is one of the strictest air cleanliness standards for cleanrooms. It allows for a maximum of 3,520 particles of 0.5 microns or larger per cubic meter of air. It also permits no particles larger than 5 microns. This extremely low particulate count makes ISO 5 suitable for processes that require an ultra clean environment, such as semiconductor manufacturing, pharmaceutical production, and biomedical research.

Key specifications of ISO 5 equivalent grade:

  • No more than 3,520 particles of 0.5 microns or larger per cubic meter
  • No particles 5 microns or larger allowed
  • Positive air pressure differential from lower grade areas
  • High efficiency particulate air (HEPA) filtration
  • Air exchanged at least 20-30 times per hour
  • Strict gowning procedures for personnel
  • Airlock entrances
  • Vibration isolation

Meeting these stringent ISO 5 specifications requires the use of HEPA filters, laminar air flow, proper pressurization, careful gowning procedures, and constant monitoring. Facilities must rigorously control potential sources of particles and maintain proper air flow patterns to achieve ISO 5 status.

Why is ISO 5 important?

ISO 5 environments provide critical contamination control for sensitive manufacturing processes. The ultra clean air reduces defects, improves yields, and ensures quality results. Some key reasons why ISO 5 is important include:

Preventing defects and yield loss

Particles can directly cause defects in miniaturized semiconductor circuits and other precision technologies. Maintaining an ISO 5 environment prevents harmful airborne contamination from reaching the product and protects yields.

Enabling advanced technologies

Emerging nanoscale devices and biological therapies rely on extremely clean manufacturing conditions only possible in ISO 5 and better cleanrooms. ISO 5 enables these cutting edge innovations.

Protecting product purity

Pharmaceuticals and biologics can be compromised by particulates and other impurities. ISO 5 cleanrooms provide an ultra pure air environment to preserve drug and therapy purity.

Safeguarding health

In medical research and patient treatment facilities, ISO 5 cleanrooms prevent airborne microbes and allergens from endangering vulnerable individuals. An ISO 5 environment is critical for health and safety.

Meeting customer requirements

Many advanced technology consumers demand ISO 5 or better standards from their suppliers. Meeting ISO 5 specifications satisfies customer requirements for ultra clean manufacturing.

How is ISO 5 cleanliness maintained?

Achieving and preserving ISO 5 cleanliness demands rigorous contamination control measures and constant monitoring. Here are some key ways ISO 5 status is maintained:

HEPA filtration

99.97% minimum efficiency HEPA filters remove particles 0.3 microns and larger. ISO 5 cleanrooms use fan filter units with HEPA filters to continually filter recirculated air.

Air changes

Frequent air exchanges flush out particulates. ISO 5 cleanrooms exchange all air at least 20-30 times per hour.

Positive pressure

Higher air pressure inside the ISO 5 space keeps less clean air from infiltrating from external areas.

Air showers

Personnel enter through air showers that blow away particles as they gown and transition into the cleanroom.

Strict gowning procedures

Workers wear protective clothing covering all skin and hair that could shed particles. Garments are donned in a specific sequence.

Constant monitoring

Particle counters continuously sample air to ensure ISO 5 levels are upheld. Alarm systems alert if counts exceed limits.

Proper materials and cleaning

Low-particle construction materials are used. Surfaces are regularly cleaned to remove contaminants.

Disciplined personnel

Workers must follow protocols to minimize particle generation from clothing, tools, activities, and workflows.

What are typical ISO 5 applications?

Due to its ultra cleanliness, ISO 5 is suited for only the most critical and sensitive processes. Some common ISO 5 cleanroom applications include:

Semiconductor manufacturing

Microchip production, especially below 130 nm geometries, requires ISO 5 to prevent yield loss from particle defects.

Pharmaceutical processing

Protecting product purity for injectable drugs and sterile filling processes demands ISO 5 conditions.


Cell and gene therapies, vaccines, and other biologics benefit from ISO 5 during manufacturing.

Medical devices

Crafting precision instruments like implants and diagnostics needs ISO 5 particle control.


Many advanced optical systems are assembled in ISO 5 cleanrooms to prevent contamination.


Spacecraft components may require ISO 5 for critical applications like sensors or telescopes.


Emerging nanoscale materials and devices are fabricated in ISO 5 environments.

What are the costs associated with ISO 5 cleanrooms?

Developing and operating an ISO 5 cleanroom requires major investments. Key costs factors include:

Facility construction

Purpose-built cleanroom infrastructure with tightly sealed walls, floors, and ceilings is expensive to construct.

HEPA filtration

ISO 5 needs high capacity systems with thousands of HEPA filters and big fan units to maintain air exchanges.

Monitoring and alarm systems

A network of particle counters and alert systems adds substantial expense.

Energy for air handling

Large amounts of energy are consumed running the extensive air filtration and exchange systems.

Consumables and garments

Ongoing costs for specialized cleaning supplies, apparel, tools, and materials.

Personnel training

Workers require extensive training on gowning, behaviors, and operating procedures.

Can ISO 5 cleanliness be achieved without a cleanroom?

Reaching ISO 5 specifications generally requires constructing an actual cleanroom with rigorous contamination controls. However, there are a few limited cases where ISO 5 levels could potentially be attained without a true cleanroom:


Gloveboxes and isolators with HEPA filtered air supply may reach ISO 5 for small chamber volumes.


Small enclosures around a work process can be purged with clean air to potentially achieve ISO 5 locally.

Unidirectional air flow

Utilizing laminar flow systems in an open space could potentially meet ISO 5 in a very restricted area.

Portable cleanrooms

Some temporary and modular cleanrooms can reach ISO 5 classification when properly installed.

However, these options are not true substitutes for a well-designed permanent ISO 5 cleanroom. They may struggle to maintain the desired particulate levels over time. Consult cleanroom specialists to evaluate if limited alternatives could potentially work for your specific situation.

Comparison of ISO standards for cleanroom classification

ISO 5 is one of several ISO cleanroom standards defined by particle concentration. Higher numbers represent lower cleanliness, while ISO 1 is the cleanest classification. Here is an overview of key ISO cleanroom standards:

ISO Class Maximum particles/m3 ≥ 0.1 μm Maximum particles/m3 ≥ 0.2 μm Maximum particles/m3 ≥ 0.3 μm Maximum particles/m3 ≥ 0.5 μm Maximum particles/m3 ≥ 1 μm Maximum particles/m3 ≥ 5 μm
ISO 1 10 2 1 0 0 0
ISO 2 100 24 10 4 0 0
ISO 3 1,000 237 102 35 0 0
ISO 4 10,000 2,370 1,020 352 0 0
ISO 5 100,000 23,700 10,200 3,520 293 0
ISO 6 1,000,000 237,000 102,000 35,200 2,930 0
ISO 7 352,000 83,000 35,200 8,320 2,930 29
ISO 8 3,520,000 832,000 352,000 83,200 29,300 293
ISO 9 35,200,000 8,320,000 3,520,000 832,000 293,000 2,930

As shown in the table, ISO 5 allows substantially higher particle concentrations than the strictest ISO 1, 2, and 3 standards. However, its maximum particulate levels are still extremely low compared to general indoor or outdoor environments. Maintaining ISO 5 cleanliness requires very rigorous contamination controls.


ISO 5, or Class 100, defines an extremely clean environment critical for advanced manufacturing processes and products. Though costly to implement and maintain, its ultra low particulate levels prevent defects, reduce biological risks, and enable emerging innovations that demand the highest levels of purity. With proper facility design, equipment, monitoring, and operating discipline, the stringent ISO 5 classification can be sustained to reap its benefits.