The History of the Cleanroom

By Erin Biba

There are few more essential tools to a scientist then the ability to keep contaminants out of their research.

Science could never get done without the right tools. And all that gear has to come from somewhere. Many of the gadgets sitting on laboratory shelves around the world have histories just as interesting as the discoveries they've made. Each month we're telling the stories of how the most important lab tools came to be.

There are few more essential tools to a scientist then the ability to keep contaminants out of their research. Dust, microbes, and even vapors can screw up delicate experiments. And as science gets more and more precise, sometimes even a single atom out of place could mean the difference between successful science and total failure. This is why we have cleanrooms. They control the level of contaminated air inside a space and allow scientists to do delicate work without fear that a rogue element will upend everything.

Willis Whitfield invented the cleanroom in 1962. It was a revolution at the time -- the design schematics for the first "ultra-clean room" even has a patent: US3158457 A. But 1962 wasn't all that long ago. It's hard to believe that no one was protecting their environments from contamination before then.

Photo Credit: NASA/Chris Gunn

People were certainly trying. According to a paper on the history of the cleanroom by Daniel Hollbrook, a historian at Marshall University, the earliest people to make an attempt at creating controlled environments were watchmakers. It makes sense if you think about it -- they were dealing with teeny tiny parts that had to move in tandem and even a small speck of dirt would throw off their delicate work. In the 1850s one American watch factory, he says, solved the problem of dirt getting into their watch parts by physically moving their entire company from the polluted city of Roxbury, Massachusetts, to a more rural part of the state. Then they located the actual room where they built the watch mechanics above ground level. It was one of the first instances of an isolated area dedicated to building mechanisms.

US Patent US3158457 A

The next step forward in cleanrooms, according to Hollbrook, happened during World War I when a company called Miniature Precision Bearings, which made tiny ball bearings, realized that airborne particles were affecting the consistency of their manufacturing process. In 1939, MPB managed to solve the problem by introducing air conditioning into their plant. The A/C was so successful at filtering particles out of the air that when they built a new plant in 1956 they dedicated special manufacturing areas called "white rooms" that had air filters designed to remove dust. Workers inside the rooms were required smocks and caps -- and they weren't allowed to sneeze.

Also in the 1950s came advances in surgical cleanrooms. Though surgeons had been trying to maintain clean environments during surgery since the 1870s, those efforts were mostly geared towards keeping doctors from bringing contaminants in with them from the outside. But little had been done to stop the spread of disease once these particles were already inside. During World War II, however, cramped conditions in wartime medical centers prompted research into ventilation technology. Out of this research came High Efficiency Particulate Air (HEPA) filters and an understanding of laminar airflow (systems that make air move in only one direction).

By the 1960s, according to a NASA report, cleanrooms were beginning to become a hot ticket item for military and space manufacturing. The US Air Force, in fact, was hard at work establishing just what, exactly, would be the standard practice for design and implementation. There had been a few disparate cleanrooms popping up around the country -- but nobody was making them in the same way. Each one was being tailored to the specific needs of a product's manufacturing process.

Around this time, in 1961, Willis Whitfield was working at Sandia National Laboratory running a team that was tasked with keeping nuclear production facilities as clean as possible. According to Sandia Lab historians, the practice in most cleanrooms at the time was just to seal everything up really tight and vacuum a lot. It was less than effective. So Whitfield and his team designed a room that would constantly circulate air through filters. It was capable of completely replacing all the air in a room 10 times every minutes. According to a story in the Sandia Lab News: "When the first cleanroom was tested "the dust counters went to nearly zero. We thought they were broken," Willis said in a 1993 videotaped interview."

photo via Sandia National Laboratories

In 1962 (or 1963 depending on which source you ask) the USAF convened a group of 200 cleanroom experts at Sandia to establish standard rules for how the rooms would work. Out of this came an early version of the ISO levels we use to rate cleanrooms today. But by far the most successful cleanroom standardization to come out of Sandia was Whitfield's design, which, because it was patented, can be measured: within just a few years from its introduction the patent resulted in nearly $50 billion worth of cleanrooms to built around the world including by companies like RCA and General Motors. Whitfield later went on to assist NASA with sterilizing spacecraft. And Time Magazine dubbed him "Mr. Clean."

Today cleanroom technology is an entire industry unto itself. The technology has its own Global Society for Contamination Control. Standards for what goes inside a cleanroom these days specify every piece of fabric or material that's brought in. Ceiling tiles and lamp shapes aren't safe from regulation. Some cleanrooms even utilize ionizers to control the electrical charge of the particles floating around inside (this makes sense in semiconductor production facilities that do things like build transistors one atom at a time). Without the breakthrough of cleanrooms most of the technology we have today would not only be much less reliable, but even more likely it wouldn't exist at all.