Cleanroom Gowning Procedures & Garment Standards

Even in the most advanced cleanroom where airflow, filtration, and layout have been expertly designed, the greatest contamination threat often walks in on two feet. Personnel are the single largest source of particle contamination in cleanroom environments, and without proper gowning protocols, even the most robust controls can fall short.

Cleanroom gowning is the controlled process of dressing personnel in specially designed garments before entering a cleanroom. These garments, such as coveralls, hoods, boot covers, gloves, and face masks, minimize the emission of particles from the body and prevent contaminants from entering the environment.

The process is governed by standard operating procedures that vary by cleanroom ISO classification and industry-specific regulations. Gowning is not only about wearing the right gear, but also about doing so in the correct order, in a clean environment, and with attention to hygiene and donning technique.

Why This Matters

The average person sheds millions of skin flakes and hair fragments per day, most of which are invisible to the naked eye. Even breathing and talking emit particles that can compromise sterile operations or precision equipment. In high-precision industries, the presence of a single contaminant can cause product failure, regulatory violations, or costly downtime. 

Cleanroom gowning also helps: 

• Maintain compliance with ISO, GMP, or FDA regulations
• Extend the lifespan of cleanroom infrastructure and air filtration systems
• Protect personnel from exposure to hazardous substances

In short, gowning is a can’t-miss element for any cleanroom contamination control strategy. So, let’s get into how you can execute it. 

Gowning Area Design and Layout

Cleanroom gowning procedures vary based on ISO class and industry requirements, but a typical process includes the following steps: 

1. Remove all jewelry and cosmetics before entering the gowning area.
2. Enter the pre-gowning space to put on dedicated undergarments like scrubs, hairnets, and shoe covers. 
3. Enter the gowning room through a step-over bench or barrier. 
4. Put on cleanroom garments in this sequence: 
   1. Bouffant cap or hood
   2. Face mask
   3. Coverall (zip and full fasten)
   4. Gloves (over cuffs)
   5. Boot covers or cleanroom shoes
5. Do a visual inspection in front of a mirror for complete coverage.
6. Do a glove sanitation step before entering the cleanroom.

In ISO Class 5 or more stringent environments, additional garments such as goggles, second layers of gloves, or sterile gowns may be required. Depending on the nature of the process your cleanroom will house, you may have some other discrepancies to the process above. Regardless, gowning procedures should always be documented, trained, and audited to maintain consistency and reduce contamination risks.

Different applications and ISO classifications require specific gowning components. The table below summarizes common garments by cleanroom class. 

Check the ISO 14644-1 standard for more cleanroom garment standards and specifications.

Cleanroom garments are typically made from low-linting, nonwoven synthetic fabrics such as polyester or Tyvek^® to minimize particle generation. For sterile environments, garments may also be sterilized and individually packaged. 

Garments should be selected based on: 

• ISO classification level
• Electrostatic discharge (ESD) requirements
• Sterility requirements
• Reusability or single-use policies

The donning order is important because it ensures that clean garments aren’t contaminated by previously donned or unprotected body parts. For example, gloves must go over the cuffs of coveralls to seal particle pathways. And boot covers should be the last item worn to prevent floor contamination during earlier steps. 

Just as entry requires careful gowning, exiting a cleanroom should follow similarly strict protocols to prevent cross-contamination and ensure proper disposal or reconditioning of garments. 

1. Step into the exit gowning area or airlock.
2. Remove outer gloves and dispose of them in a designated bin.
3. Remove gowning items in reverse order, being careful not to touch outer surfaces.
4. Put reusable garments in the soiled garment bin or hang on a designated rack for laundering.
5. Dispose of single-use garments in proper waste containers, according to cleanroom waste segregation policies.
6. Use hand sanitizer or a handwashing station to practice proper hand hygiene before fully exiting.

Once taken off, cleanroom garments should be properly disposed of or reconditioned following IEST-RP-CC003 standards for cleaning and garment maintenance. 

Cleanroom gowning is more than just putting on a suit. It’s a carefully choreographed practice that protects products, personnel, and processes. Whether your facility operates under ISO 8 or ISO 5 conditions, effective gowning starts with proper layout design, consistent procedures, and industry-specific garment selection.

At Encompass Cleanrooms, we offer turnkey cleanroom design-build services that prioritize contamination control strategies. From entry to exit, we can help your facility meet stringent regulatory and operational standards so that your people and products are protected. 

Reach out today to get your project started.