wikiHow to Enter a Cleanroom

A cleanroom is an environment, typically used in manufacturing or scientific research, that has a low level of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapors. If you have been asked to work in one, you'll need to take the appropriate steps to avoid introducing contamination.

There is no single type of cleanroom or single set of rules for entering, so make sure to get training and instruction for the particular cleanroom you will enter.


  1. 1
    Understand the purpose of cleanroom protocol. Processors require clean rooms because any speck of dust can damage the processes that occur inside them. Physical contaminants include skin cells that flake off, dandruff, clothing fibers, and loose hair. Paper, pencils, packaging materials, and many other things shed dust, and even tiny particles can damage the delicate products built and tested in clean rooms.
  2. 2
    Know what class of cleanroom you're entering. There are a couple of different sets of standards, but in general, the lower the number, the cleaner the cleanroom.
  3. 3
    Recognize that humans are generally the single largest source of contamination within a cleanroom.
  4. 4
    Follow the instructions given by your employer or whoever operates and maintains the cleanroom. Clean room apparel varies. It may consist of gloves, a cap, and smock at its most basic all the way up to a full "bunny suit". These are the general instructions.
  5. 5
    Shower in the morning on any day you will enter a cleanroom.
  6. 6
    Powder = particles.
    Do not wear cosmetics, hair spray, perfumes, or colognes into a cleanroom.
  7. 7
    Wear appropriate attire under your cleanroom garb. Skirts, high-heeled shoes, shorts, and in some cases, short-sleeved shirts are not appropriate attire. Also steer clear of clothing that is especially fuzzy or tends to produce a lot of lint or static electricity.
  8. 8
    Clean or change your shoes on the way in. Wherever possible, do not wear outdoor shoes into the cleanroom environment; change into a clean and appropriate pair of shoes dedicated for the lab environment

    • If there is a machine at the door for this purpose (spinning brushes), use it. Place your foot and shoe together inside it. Hold the handle to steady yourself, then press the button. You'll feel a slight tug on your shoe from the moving brushes, but it won't damage your shoe.
    • If there is an adhesive doormat, step on it several times.
  9. 9
    Stow personal items you won't be taking into the cleanroom. Leave them at your desk or use lockers, if they are provided.
  10. 10
    Discard candy, gum, or anything else in your mouth.
  11. 11
    Put on your cleanroom gear in the correct order. Top-to-bottom is a good general rule to follow, and it is a good idea to use a bench to separate the "dressed" area from the "getting dressed" area.

    • Start putting on your cleanroom gear on the "getting dressed" side of the bench.
    • Put on a hair cover (bouffant cap) and/or hood. Use a beard cover to cover any facial hair beard or mustache). Adjust hood when closing snaps on front and back so it is snug and comfortable.
    • An inspection process with hoods and coveralls.
      Put on coveralls or a smock. If in two parts, put on jacket first, then pants. Zip or snap it closed all the way up, over the neck of the hood if you are wearing one. Close any snaps at the cuffs to gather the sleeves snugly around your wrists.
    • Sit on the bench to put on shoe covers or booties. Be sure to tuck pants inside the booties, and don't let the booties touch the ground on the "getting dressed" side of the bench. Alternatively, use an automatic shoe cover dispenser.
    • Put on latex gloves, or the appropriate substitute for those allergic to latex. Tape sleeves and ankles if necessary.
  12. 12
    Act as if you are now a surgeon: don't touch anything until you are in the cleanroom. If it is necessary to touch surfaces or items, be sure to change the affected glove before entering the cleanroom.
  13. 13
    Pass through the air shower if there is one and step on any additional adhesive mats as you enter.
  14. 14
    A wafer handler.
    Keep cleanroom protocol in mind whenever you work within a cleanroom.

    • Keep your cleanroom apparel on at all times when working in the cleanroom.
    • Do not bring in any of the following items: pencils (note that graphite is conductive), erasers, non-cleanroom paper, wood, abrasives, or packaging materials such as cardboard. Keep non-cleanroom paper in a plastic sleeve if you must refer to it. Use only cleanroom tape. Be aware of what else you bring in.
    • Correctly wipe down any equipment you bring in. Do not remove cleanroom equipment from a cleanroom.
    • Move slowly and evenly. Rapid, sudden, or jerky movements can shed many particles.
  15. 15
    Replace any cleanroom attire that is worn or soiled. Even cleanroom apparel gets dirty as you wear it and work in it. If it has been a while, make sure you have yours cleaned and get a fresh one.

    • Use fresh gloves, hair covers, and disposable shoe covers every time you enter.
    • You can reuse smocks, coveralls, reusable shoe covers, and reusable caps or hoods, but exchange or have them cleaned periodically.
  16. 16
    Remove cleanroom attire in the opposite order from that in which you donned it. Remove cleanroom attire each time you leave the cleanroom. Do not exit the cleanroom wearing or carrying cleanroom attire. Put it on each time you enter and take it off and store it correctly each time you leave.


  • The order of your preparation matters. For instance, if you put on your gloves and then use your hands to gather your hair and put it under a cap, the gloves will have oil and skin flecks on the outsides from your hair. Ask what the correct procedure is. If you're still not sure, go from inside to outside, and dirtiest to cleanest.
  • Smokers will be subject to stringent regulations as to where they may smoke. A "standard" procedure requires smokers to exit the building, then only smoke in designated areas at least 100 yards (100 metres) from the building, then wait at least five minutes after smoking before re-entering the facility.
  • If you visit a cleanroom you do not normally enter, find out the correct procedure for gowning.
  • Always ask for instructions from others who work in or maintain the cleanroom, and follow those instructions rather than these ones, if they differ.
  • If there is an airlock or gowning room on the way in, open only one door at a time.
  • If the cleanroom deals with electronics, you may need to follow additional procedures to cut down on electrostatic discharge (ESD) for sensitive items.
  • Get cleanroom attire that is the correct size for you. You will be much more comfortable working in a suit that fits, especially if you spend a lot of time in it.

    • Try on smocks, bunny suits, and shoe covers or ask to be measured for them when you first start. Use the included snaps to adjust the size further.
    • Learn what size gloves you wear. If your hands sweat in latex gloves, see if you can get fabric glove liners to go underneath.
    • Get prescription safety glasses if you wear glasses. Your employer may offset the cost, and they are far more comfortable than wearing safety glasses over your glasses.
    • Hair and beard covers generally come in only one size.
  • Microelectronics are sensitive to more than particles.
    If you're working with electronics, take the appropriate steps to control electrostatic discharge (ESD).


  • In the event of a fire or evacuation alarm, do not stop to remove your cleanroom attire. Follow posted exit routes if available and directly exit the facility. After emergency is over, obtain new cleanroom attire before entering the cleanroom once more.
  • Understand any safety issues involved in working in a cleanroom. There may be hazardous materials, heavy equipment, high temperatures, sharp objects, tight spaces, and high voltage. If you are working alongside any of these or other hazards, be sure you are properly trained for them. Understand and follow the proper precautions.
  • Never eat, drink, or smoke in a cleanroom.

Sources and Citations

  • Intel's discussion on entering their very clean cleanrooms. Your cleanroom experience may be very different from the detailed procedure they describe.
  • Introduction to Cleanrooms, Vanderbilt University.

Article Info

Featured Article

Categories: Featured Articles | Work World