When many people, especially outside the cleanroom industry, think of cleanrooms, they envision scientists garbed head-to-toe in white with microscopes sitting atop stainless steel tables with sparse else in the room. And, those types of cleanrooms do exist, but the diversity of cleanrooms has exploded since its invention in 1960.
It is hard to believe it has only been 60 years since cleanrooms were first implemented. Of course, there were many rooms that had cleanliness and sterility in mind, such as operating rooms and even manufacturing facilities. But their focus on and ability to deliver removal of particles and control contamination had not yet been fully implemented.
Basically, a cleanroom actively controls contamination. The target contamination may be different for each application such as pharmaceutical manufacturing, electronics and medical device manufacturing, aerospace, printing and graphics, and even horticultural endeavors such as cannabis growing facilities. Though anti-static or anti-microbial specifications are a part of the equation for some industries’ cleanrooms, all cleanrooms must control particle count as it contributes to contamination of all types. The limits of the particle concentrations are set by the requirements of the processes occurring within the facility. Read more about cleanroom classifications and related testing.
Cleanroom standard operating procedures (SOPs) are put in place to keep contamination from being increased by people and equipment as well as to remove contamination that does find its way into the space. Cleanroom cleaning procedures help to test for and remove contamination.
Early Attempts at Medical Clean Rooms
The first efforts at making rooms clean for conducting a process were hospital operating rooms.
Use of sterilized environments for surgery began in the mid-19th century. But even before that as early as the US Civil War, medical attention to controlling the environment are documented.
Excerpt from Tim Sandle of University of Manchester in a paper on “The development of cleanrooms: an historical review.“ :
Public domain, via Wikimedia Commons
…surgeons in the American Civil War (1860-1865) acknowledged the environmental risks from field surgery. For instance, army physicians speculated that the spread of pus formation from one patient to another was probably airborne. Furthermore, in 1864 the American Medical Association campaigned for ventilation of the hospitals to be improved as a means to creating cleaner air. Although of contamination from air, equipment, surfaces, and people were generally acknowledged as important risks during surgical procedures; little improvement was made to the cleanliness until the work of Lord Joseph Lister became accepted. One of Lister’s concerns was with the spread of post-operative infections and in response he pioneered the use of aseptic methods in surgery. Inspired by the work of Louis Pasteur on ways to destroy microorganisms, Lister experimented with surgical dressings soaked with carbolic acid (phenol) to cover the wound; and with hand-washing, sterilizing instruments and spraying carbolic in the operating theatre whilst surgery was performed, in order to limit infection.
As discoveries through medical research and trial and error developed, it became clear that preventing infections by keeping the surgical theater clean was as important, if not more important, than resolving infections that came about because of non-sterile conditions.
Early Use of Clean Room Concepts in Industry
While the medical use of “clean rooms” was developing as early as the 19th century, the industrial use of cleanliness was late to form with little development even in the early decades of the 20th century. Though the lack of cleanliness led to machinery breakdown or to less than stellar products especially in heavy dust, the industrial cleanroom concepts lagged. Housekeeping and segregating manufacturing processes were the primary means of trying to reduce the problems of heavy dust.
One of the earliest references to “industrial” applications for environmental cleanliness was when a Swiss watchmaker used a bell jar placed over watches during their assembly when he was not actively working on them. This reduction of dust was an early attempt at a clean space to improve quality of production.
While this barrier method is still vital in today’s cleanrooms, filtration had not yet been invented. This developed from another industry, that of fire-fighting. smoke inhalation.
In 1823, John and Charles Deane invented a “smoke helmet” that consisted of a copper helmet with an attached flexible collar and protective garment.
A long leather hose attached to the back of the helmet supplied air via bellows. The incoming air was filtered. A short pipe allowed exhaled air to escape.
This revolutionary helmet protected firefighters from smoke and dangerous chemicals in the air when they entered burning buildings. The helmet was later adapted to a similar device for sea-diving. Then in World War I, Cluny Macpherson adapted the filtered helmet idea to invent gas masks. The gas mask was the foundational technology for today’s HEPA (high-efficiency particulate air) filtration.
As early as just after the turn of the 20th century, work areas were segregated to reduce cross-contamination between manufacturing areas. As improvements arrived, the rudimentary cleanrooms became more effective. For example, in the 1950s, HEPA filters came into use inside cleanrooms.
During WWII, more sophisticated cleanrooms provided not only particle control, but also a focus on sterility and safety, to manufacture then state-of-the-art weaponry and more mundane parts such as ball bearings. The absolute filter technology developed for these environments was declassified after WWII opening up its use in other industrial applications.
As technology expanded and industrial needs changed, cleanrooms improved for the betterment of projects. But, in the early history of cleanrooms, these facilities still had contamination as particle removal, monitoring, and control remained outside the scope.
Considering that on person standing motionless in a cleanroom can generate more than 100,000 particles per minute, that scope of particle contamination was key to address.
The First Modern Cleanroom
The first big leap to modern cleanrooms came from the nuclear industry. Following the creation of the nuclear bomb, heavy financial investment resulted in the application of HEPA filters to create high-velocity laminar air to sweep away contamination.
The first modern cleanroom is credited to an American physicist, Wills Whitfield, who led a team at the Sandia Corporation (later Sandia National Laboratories) in Albuquerque, New Mexico.
Whitfield and his team created cleanrooms with a constant, high-filtration airflow or laminar airflow to protect cleanroom workers from nuclear particles.
What made his creation different from earlier attempts at creating clean rooms for surgery and manufacturing applications was creating a predicable airflow which made it possible to better control particle contamination. This same concept is used in cleanrooms today though technology of how to create the airflow and to remove obstacles impeding the constant flow have changed over time, the concept is still tried and true.
Though the earliest uses of constant, highly filtered air targeted high protecting cleanroom workers from hazardous materials, its use is also for higher quality manufacturing which requires reducing contaminants introduced during the processes. Today, laminar air flow is used for a large variety of applications such as in compounding pharmacies where staff works with chemotherapy preparations, the airflow helps to maintain sterility that protects recipients of the cytotoxic drugs and helps to protect the pharmacists from contamination while handling these drugs.
Industrial Cleanrooms Differ Widely
Preparations of pharmaceutical, biological, and medical products require clean, often, sterile spaces to control viable (living organisms) and nonviable particles that could impact the finished product’s sterility. These pharma/biotech cleanroom environments often have a strong focus on protecting workers from harmful exposure to drugs that are being manufactured or handled. Learn more about the history of compounding pharmacies from prehistoric times to their demise in the 19th century to today’s resurgence.
Semi-conductors are small and more fragile than we often think. Especially during manufacture when the smallest bit of dust or lint can impact the microelectronic devices performance greatly. Often, impacting the safety of everyday people. Microelectronic cleanrooms control particles, ESD, and often gasses and chemicals.
Flat Panel Display Factory Cleanrooms
As flat panel displays (FPD) proliferate in TVs, computers, tablets, phones, smart watches, camcorder viewfinders, and a myriad of other small to extremely large applications, the manufacturing is under constant pressure to produce high quality displays in record time. One key aspect is use of cleanrooms. FPD manufacturing facilities are some of the largest cleanrooms in existence, some greater than 2,000,000 sq ft. FPD factory cleanrooms control ESD, particles, and chemical concentrations.
Automotive cleanrooms address a wide variety of contamination control needs. Design, production, assembly, and testing of automotive components and even lower tech activities such as painting require controlling dust, vibration, ESD, gaseous emissions, and many more factors. With automotive technology becoming more intelligent and highly calibrated with safety becoming a greater issue, automotive cleanrooms continue to evolve.
As we discussed in the history section above, military and aerospace cleanrooms have been some of the biggest contributors to the evolution of cleanroom technology. With funding less of an issue and the tolerance for error being zero, the aerospace industry cleanrooms continue to lead. Their pristine production conditions are used throughout subassembly, assembly, testing, product and component cleaning, and packaging processes.
Aerospace cleanrooms often control ESD, UV, vibration, gasses, and, of course, particle contamination.
When you hold a book or read a movie poster or view a billboard whizzing by, you probably never think about the process that goes into creating those products. Sure, you may have thought about the amazing processes that must go into the assembly or the color printing, but cleanrooms for graphics and printing applications are used to control lint, dust, static buildup, and introduction of adhesives or oils that mar the product and damage the machinery.
Food Processing/Handling Cleanrooms
The food processing and handling industry’s cleanroom applications are very diverse. From processing animals and plant products straight off America’s farms to prepping and packaging for final consumption, the cleanrooms address controlling particles and static that can affect both products, machinery, and staff, as well as sterility where applicable.
Hydroponics Cleanrooms for Cannabis & Hemp
Whether designing modular cleanrooms or traditional facilities, our cleanroom supplies for cannabis and hemp growing for medicinal use can help you ensure regulation compliance, grow healthy and healthful plants, and protect your workers.
These are only a few of the applications that the technological discoveries and inventions have led to using cleanrooms over the last 200 years. As we have mentioned, design of clean spaces covers much more than control of particle concentrations and may include air microbes, temperature, humidity, pressure, electrostatic discharge (ESD), gaseous contamination, and even vibration and sound. No matter the contamination, high quality cleanroom supplies and cleaning products are required to maintain the specifications. Our staff looks forward to helping you identify effective and economical ways to protect your products and your workers.