Even though a cleanroom is a space known for being highly regulated in order to prevent contamination, the room itself still needs regular maintenance and attention in order to keep what’s inside clean and sanitized. Whether it’s a weekly or monthly scheduled cleaning or the cleanroom is shut down for a thorough facility cleaning, having the right processes in place can ensure that the work being done inside the room is protected.

Contaminants in a cleanroom come from four major sources: environment, process, tools, and people. Contamination from people is the most common, so it’s important to have a strong training program to ensure any new staff are fully aware of their responsibilities. However, having an established process to prevent contamination from all of these sources is essential in saving both time and money. While each cleanroom will have its own process and will have different standards depending on the type of work being done, there are certain rules and regulations that can be used in any space.

At SOS Cleanroom, we provide a large collection of hard to find cleanroom supplies. Since 1981 we have supplied cleanroom products to government agencies, educational institutions, and a variety of other industries. What began with optical systems and technical lighting grew into supplying dozens of other products including swabs, apparel, gloves, gowns, sticky mats, and so much more. Whatever your needs are, you can count on SOS Cleanroom to provide the cleanroom supplies and custom products you need.

Quick Answer: How Often Should You Clean a Cleanroom?

Cleanrooms should be cleaned daily, weekly, and as-needed based on their ISO classification and specific industry needs. Daily cleaning tackles high-touch surfaces, while weekly and monthly cleanings focus on deep-cleaning hard-to-reach areas and equipment maintenance to ensure full regulatory compliance.

Understanding Cleanroom Classifications

Cleanroom classifications, such as those outlined in ISO 14644-1, determine the level of cleanliness required based on the number and size of particles allowed per cubic meter of air. Cleanrooms are categorized from ISO Class 1 to ISO Class 9, with ISO 1 being the cleanest and ISO 9 allowing the highest level of particle contamination.

Each classification affects not only the air filtration system but also the cleaning protocols. For example, an ISO 5 cleanroom used in semiconductor manufacturing requires a much stricter cleaning regimen than an ISO 8 cleanroom used for general manufacturing. The more sensitive the product or research being conducted, the more frequent and thorough the cleaning needs to be.

Cleanroom Cleaning Methods

Cleanroom cleaning relies on two primary methods: dry cleaning and wet cleaning. Each method is chosen based on the level and type of contamination, and both are crucial for maintaining cleanliness.

Dry Cleaning involves wiping down surfaces with dry, absorbent cleanroom wipers designed to trap particles without shedding fibers. Polyester cleanroom wipers are especially effective, as they are durable, low-lint, and resistant to chemicals. Dry disposable wipers can also be used for daily tasks such as wiping down workstations or sensitive equipment.

Wet Cleaning is required when dry wiping alone isn't sufficient to remove contaminants. This method involves using non-ionic, non-foaming cleaning solutions along with pre-wetted wipers or sterile wipers. Pre-wetted cleanroom wipers are particularly useful because they come saturated with a cleaning agent that is safe for cleanroom environments, ensuring a consistent application of the solution without the risk of overuse or spillage. Wet cleaning is generally used for deep-cleaning surfaces like floors, walls, and the interior of containment cabinets.

Daily, Weekly, and Monthly Cleanroom Cleaning Tasks

The frequency of cleanroom cleaning depends heavily on its ISO classification and the specific needs of the industry. However, a structured schedule is crucial for maintaining cleanliness and ensuring regulatory compliance.

Daily Cleaning Tasks

Daily cleaning focuses on high-touch and frequently used surfaces to prevent the accumulation of particles. Operators should begin each day by wiping down workstations, equipment, and high-traffic areas using dry wipers or polyester cleanroom wipers. These tools effectively remove particles without adding fibers or contaminants back into the cleanroom. Floors should be vacuumed using HEPA-filtered vacuums to capture any particles that may have settled overnight. At the end of the day, all surfaces—whether used or not—should be wiped down again using pre-wetted wipers. The goal is to remove any debris or contaminants introduced during daily operations.

Weekly Cleaning Tasks

Weekly tasks are more thorough, focusing on areas that aren’t cleaned daily but still accumulate dust and particles over time. Walls and ceilings should be wiped with sterile wipers soaked in non-foaming, cleanroom-approved cleaning agents. Floors, already vacuumed daily, should receive a deeper clean with cleanroom detergents for effective decontamination. Windows, pass-throughs, and shelves should also be wiped down using polyester wipers to maintain a low-lint environment.

Monthly/As-Needed Cleaning Tasks

Monthly cleaning focuses on deeper decontamination tasks. This includes the replacement of sticky mats and the thorough cleaning of air filtration systems and vents. Equipment maintenance is crucial, ensuring that vacuums, mops, and other cleaning tools remain sterile and compliant with ISO standards. Additionally, sterile wipers should be used to clean light fixtures, shoe cleaners, and other equipment that may contribute to particle build-up.

Tools and Materials for Cleanroom Cleaning

Using the right tools and materials is critical for ensuring that cleanroom cleaning is effective and compliant with regulatory standards. Depending on the cleanroom’s ISO classification, various cleaning supplies must be used to maintain sterility and prevent contamination. For example, cleanroom-specific mops, disposable gloves, and gowns are essential for avoiding particle transfer from janitorial personnel. Hair covers, beard covers, safety glasses, and surgical masks further ensure that personnel do not introduce contaminants into the cleanroom.

Cleaning agents used must be cGMP-approved, non-foaming, and neutral or non-ionic to prevent chemical reactions or residues. Deionized or distilled water is often used alongside cleanroom-specified cleaning agents and detergents for surfaces and equipment. Woven polyester wipers are particularly effective for lint-free cleaning of sensitive areas, while professional cleaners should use only non-shedding, sterile materials.

Training and Procedures

Proper training on cleanroom cleaning procedures is critical for maintaining a sterile environment and ensuring compliance with cGMP cleaning protocols. All staff, including janitorial personnel, must be thoroughly trained in cleanroom-specific cleaning techniques and gowning procedures to minimize contamination risks. The training should include how to handle cleanroom-specific mops, as well as the correct use of cleanroom wipers, such as dry, polyester, or sterile wipers, depending on the cleanroom’s class standards.

Where necessary, environmental sterilization practices and CGMP contamination prevention practices should be core components of the training program. Staff must also be trained on general equipment maintenance, ensuring that HEPA filters, cleanroom vacuums, and air filtration systems remain functional. Regular training updates ensure that employees stay compliant with evolving standards and can perform their tasks with precision.

Cleanroom Contamination Prevention Strategies

Preventing contamination in a cleanroom involves a combination of proper cleaning, equipment maintenance, and strict personnel protocols. One of the most effective strategies is to establish clear zones with controlled access, allowing only authorized personnel to enter the cleanroom. Before entry, all workers must follow gowning procedures, utilizing sterile gloves, shoe covers, and full body suits.

Additionally, strategically placing sticky mats at the entrance can help capture any particles that might be transferred via footwear. Regular use of polyester cleanroom wipers to wipe down door handles, surfaces, and equipment in high-contact areas ensures that particles don’t accumulate. Disposable wipers should be used for single-use cleaning tasks, while pre-wetted wipers are excellent for deeper decontamination.

Cleanroom Maintenance Tips

Tools and Equipment

Rather than storing cleaning products outside the cleanroom, which requires the containers to be cleaned before entering the room, keep a set of tools and equipment inside the cleanroom. In order to clean the tools and equipment, even when they appear clean, the containers need to be washed with deionized water and special surface disinfectants before they enter the room and treated with non-shedding cleanroom wipes and isopropyl alcohol.

Wiping Surfaces

To start, every surface, corner, and ledge are vacuumed and then wiped with a damp cleanroom wipe. Rather than using a back-and-forth or circular motion, wiping must be done in one direction only, either toward or away from the body. When wiping is done in any other way, it can produce more particles and contaminants than it removes. Each new stroke should use a clean surface of the wipe to prevent simply moving the particles around on the surface.

Air Filters

The airflow in a cleanroom is one of the more common ways that particles resurface in the air. Cleanrooms must use high-efficiency particulate attenuation (HEPA) filters. This will ensure the highest number of particles are removed from the room. Ionizing grids are also used to prevent static from attracting particles. To ensure that the air filters are working efficiently and effectively, they should be vacuumed every three months to remove particles. Ionized grids should be cleaned every six months. In addition, it's also important to pay attention to the time of year. Spring and fall seasons will see an increase in outdoor particles.

Preventing Grease From Spreading

There are also special processes in place for cleanrooms with machinery that require grease. These pieces of machinery are separated with polycarbonate shields that will prevent the spread of grease and limit its airborne molecular contamination (AMC). Maintenance personnel will wear three pairs of latex gloves and, after greasing the equipment, will remove the outermost glove, turning it inside out. This will ensure that grease is not dripped on the floor or door handles are not covered in grease.

Particle Counters

Cleanrooms may utilize surface or air particle counters. These can automatically check levels of particles in the air at set intervals and at various locations throughout the space. They are often placed at tabletop height, near moving conveyor belts, and at workstations — wherever the most movement is taking place.

These are just a few cleanroom maintenance tips that will help ensure your cleanroom is as clean as possible. The important thing is that new employees are thoroughly trained, the process is always consistent, and that the environment is regularly monitored for any changes.

SOS Cleanroom provides cleanroom supplies for all types of purposes and ISO Classifications. Whatever your needs are, you can count on us to provide superior service and the best cleanroom products.

Final Thoughts on Sustaining a Cleanroom Environment

Maintaining a cleanroom environment requires a multifaceted approach, combining daily cleaning protocols, specialized tools, and thorough personnel training. Using the right materials, such as cleanroom wipers, and staying compliant with ISO standards ensures that your cleanroom remains operational and contaminant-free, safeguarding product quality, safety, and compliance.