An Overview of Cleanroom Standards and Procedures: Benefits of a Pristine Environment

In industries like manufacturing or aerospace, few factors are more important than access to controlled environments. When working with incredibly advanced technology, even the smallest airborne particle can mess with your results. 

And with humans shedding around 500 million cells per day, keeping a space clean can be easier said than done. 

That’s why adopting Cleanroom Environmental Control Areas (ECA) is so important when it comes to cleaning and testing products for your business. 

With the help of common cleanroom methods, companies can maintain a contaminant-free environment for maximum results. 

To better understand these processes, let’s dive into what exactly an ECA is, what’s involved, and why it’s important. 

Key Takeaways:

  • Cleanrooms reduce particulate contamination through methods like HEPA filters and optimized architecture to provide a sterile environment for sensitive industries.
  • HEPA filters trap over 99.97% of particles 0.3 microns and larger, making them highly effective at removing contaminants.
  • Humans are the biggest source of contamination, shedding millions of cells and particles daily. Other risks include room dust, equipment, glass/plastic fragments, solvents, gases, static electricity.
  • Cleanrooms have rigorous standards for particle counts, temperature, humidity, pressurization and personnel limits that are monitored to maintain cleanliness.
  • Companies like PFC have certified sterile environments, specialized testing, and cleaning that businesses may lack the resources and experience to handle alone.

What is a Cleanroom?

A cleanroom, also known as an ECA, is a contained space in which provisions are made to reduce particulate contamination, keeping the environment as sterile as possible. 

Cleanrooms are mostly found in semiconductor manufacturing, life sciences, engineering industries, aerospace, and other industries that are sensitive to environmental contamination. 

Cleanrooms maintain their cleanliness through methods such as HEPA filters, optimized cleanroom architecture, and rigorous protocols. Standards are set which cleanrooms must adhere to in order to be suitable for the work undergone within them. 

Cleanrooms are especially useful given that particles are often too small to see with the human eye, making traditional types of cleaning not as effective in these environments. You’ll need more than a cloth and some surface spray when you’re building parts for a plane!

The very first cleanrooms appeared in medical contexts after pioneer microbiologists, and surgeons established that bacteria were directly correlated to infections. 

When it became widespread scientific knowledge that eliminating bacteria from hospital rooms would prevent infection, the original cleanrooms were created. 

They were then invented in their modern form in the 1960s by the physicist Willis Whitfield, and they’ve been crucial ever since. 

What is a HEPA Filter?

A HEPA is a type of mechanical air filter. HEPA filters were created to be used in lab and factory settings. 

HEPA stands for High-Efficiency Particulate Air and describes filters that trap 99.7% of 0.3-micron particles - the most penetrating particle size. This means HEPA filters are even more effective when it comes to trapping particles smaller or larger than 0.3 microns.  

HEPA filters are one of the main techniques used in cleanrooms to ensure the minimum number of particles possible are present in the air. 

What Do Industrial Companies Gain from a Cleanroom Environmental Control Area?

There are countless benefits of using an ECA for businesses during testing and cleaning. Let’s look at some of the main ones. 

Reduced risk of particulate contamination

A cleanroom ensures that harmful bacteria or particles don’t find their way into products. It also makes it easier for teams to work on two different projects simultaneously in the same space without fear of cross-contamination. 

Better protected equipment

Expensive equipment can be damaged when dust and small particles get trapped in machine parts. Cleanrooms can prevent this from happening. 

Reduced allergy irritation

Fewer irritants in the air can improve the health of workers by reducing allergic responses and allowing teams to better focus on their work. 

Guaranteed cleanliness of the finished product

Because the air is almost contaminant-free, the products being manufactured in a clean environment have a better chance of being clean and sterile themselves before reaching consumers. 

Faster processes

When the air quality is constantly being monitored and improved, there’s less of a risk of surfaces becoming dusty and unclean. Therefore, actions like cleaning work surfaces, removing dust, and wiping products down aren’t needed as regularly, allowing the cleaning and testing process to happen more quickly. 

Meet cleanliness and sterility requirements

Within some industries, the pursuit of cleanliness isn’t just a moral or business endeavor but one that’s required to meet regulatory standards. Using a cleanroom can ensure you’re meeting legal requirements. 

When searching for a cleanroom service provider, businesses should look out for cleanroom providers that adhere to certain standards and have procedures in place to ensure the maintenance of clean and sterile environments. 

What Are the Biggest Contamination Risks in a Cleanroom?

There are a few main types of contamination that cleanrooms attempt to eliminate in order to make the environment as sterile as possible. 

  • People. Humans are the biggest source of contamination in a cleanroom, which is said to account for around 75% of all contamination. Humans can bring bacteria with them on their clothes, hands, and body (think fingerprints, hairs, and clothing fibers), but their cells alone can also act as a contaminant. With humans shedding a serious number of skin cells per day (especially when we move), our bodies alone pose a threat. This is also why cleanroom entry standards are important.
  • The room. The actual room itself counts as a contaminant, thanks to the dust and aerosols present in the air. 
  • The equipment. Whether it’s flecks of dried processing chemicals, dust, paint flakes, or fiber dust, the equipment in use can introduce contaminating particles into the mix.
  • Glass or plastic dust. Fragments of glass or plastic can enter the air during the cleaning and testing process when they’re cut. 
  • Dirty solvents. Particles in water and cleaning solvents can make their way into a cleaning and testing environment. 
  • Process gases, water and chemicals. Process gases, water, and chemicals are commonplace in cleaning and testing environments. These substances must be properly filtered to avoid contaminating any part of the process. When selecting which gases or chemicals to bring into a cleanroom, users must also consider any potential reactions. 
  • Static electric charge. Static electricity happens when particles become charged, which can mess with the atmosphere in the cleaning and testing environment. Static also attracts airborne dust and contamination, which are problematic for processes. 

Through the use of HEPA filters as well as careful maintenance of high standards, a cleanroom seeks to remove these contaminants from the air and reduce their chances of entering in the first place. 

A Guide to Cleanroom Standards

When cleanroom providers seek to control the environment, they’ll set particular standards to do so, as well as metrics by which to judge the cleanliness of the room. Here are some of the key considerations. 


Cleanrooms are classified according to the number and size of particles of size 0.5 µm+ permitted per volume of air. The large numbers you might see on a chart like ‘class 1000’ refer to the FED_STD-209E classification.

ISO 14644-1

ISO 146441-1 standards specify the decimal logarithm of the number of particles 0.1 µm or larger permitted per cubic meter of air. 

Temperature and Humidity Control

The temperature and humidity of the cleaning and testing environment can actually play a huge part in outcomes. If the space is too dry, there’s the risk of static electricity and particulate issues. Too damp and condensation can lead to parts getting wet. Plus, both too much and too little humidity make for an uncomfortable working environment. 

Humidity and temperature readings should be obtained twice daily from the cleanroom log. The allowable relative humidity range is between 25% and 80% and the allowable temperature is 72° F ± 5° F, for the comfort of the personnel working inside the cleanroom. 


Some cleanrooms require a minimal amount of pressure as well as a mandated pressure differential between the cleanroom and adjacent areas of lesser cleanliness. 

Number of People

Since humans are one of the main contaminants along with their clothing and makeup, the number of personnel allowed in any given square meterage of a cleanroom is restricted. 

At PFC, our ISO-7 cleanroom only allows 2 people per 100 square feet. The total number of personnel allowed in the cleanroom at any one time is limited to 34, broken down as follows:

• Main Room - 14
• Test Cell - 4
• Sampling Room #1 - 6
• Sampling Room #2 - 6
• Packaging Room #1- 4.

How is a Cleanroom Monitored?

Cleanrooms are meticulously configured with HEPA filters and stringent protocols to maintain an environment free from contaminants. That being said, setting up the cleanroom to meet standards is just the initial step. Systematic monitoring is critical to keep track of the environmental conditions in the cleanroom, consequently safeguarding the ongoing projects and activities.

In terms of Engineering Cleanroom Areas (ECA), it is mandated that monitoring occurs before the commencement of daily shifts.

This routine of daily inspections for cleanliness and general upkeep is performed by production personnel, as outlined by the Q-form Q-039. This form specifically identifies the required maintenance activities, their respective frequencies, and the party responsible for performing these activities.

For instance, surfaces including but not limited to tables, vacuum ovens, and other equipment must be meticulously examined for any traces of dirt, dust, residues, lubricants, or corrosion. 

If such contaminants are found, they must be cleaned thoroughly — generally wiped with Isopropyl Alcohol (IPA) and a lint-free cloth. The cleaned surfaces will undergo a subsequent inspection, where a clean wiper is run over the surface and then presented to the inspection personnel. 

They will validate the cleanliness under a black light (ultraviolet lamp) and any traces of persistent contamination will indicate need for additional cleaning.

The inspection personnel, whether from the production or Quality team, is tasked to report any areas or systems that fail the cleanliness criteria to the Clean Room Supervisor. They may also suggest corrective measures to ensure the cleanliness standard is reinstated. 

Monitoring cleanrooms at least once per shift and addressing any issues promptly, paves the way for smoother, more efficient operations.

The Cleaning and Testing Services Your Business Needs

Naturally, for business owners wanting to transform their working environment into a cleaner and more controlled one, all of this can sound overwhelming. If you don’t have the experience, staffing requirements, or resources to manage a cleanroom yourself, it’s time to call in the pros. 

At PFC, our facilities include a large certified cleanroom - the only DOT-certified well for hydrostatic testing, the only facility for vertical cleaning of compressed gas cylinders, and the only enclosed and permitted sandblasting and painting facility in the area.

For an idea of just how effective our cleanroom space is, PFC’s ISO 7 cleanroom allows only 352,000 0.5 micron particles per cubic meter, in contrast with the ambient outside air in a typical city, which contains around 35,000,000 similarly-sized particles. 

As well as providing companies with much-needed cleanrooms, we specialize in hydrostatic testing, cryogenic and cold shock testing, oxygen cleaning, passivation, high-purity cleaning, and more. 

Thanks to our experience working with industry leaders in engineering, manufacturing, and more, we have everything you need to make your next project a success, with as little cross-contamination as possible. If you’re ready to save costs and improve results, take a look at our Precision Cleaning services or get in touch today.

About PFC: Precision Fabricating & Cleaning is an innovative, highly qualified company with unique capabilities to accomplish a wide range of industrial testing and Precision Cleaning services, specializing in Hydrostatic Testing, Oxygen Cleaning Service, Cryogenic & Cold Shock Testing, Mobile Field Cleaning, Passivating/Passivation, High Purity Cleaning, Ultrasonic Cleaning, and so much more.

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