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Proper gowning is an important part of cleanroom maintenance and serves to prevent, or at least minimize the contaminations and particle formation arising from human body and clothing. Human can be considered as the “dirtiest” object in a cleanroom and the main source of contamination. Recall that the airflow in a cleanroom is downwards i.e., from ceiling to floor. Thus, floor is the dirtiest place and is where most particles are found. Thus, gowning steps (listed below) should be from top to bottom, while de-gowning is in reverse order:

  • Remove your coat or jacket before entering the cleanroom. There’s a coat rack available at the corner of cleanroom entrance. Personal items should not be carried into cleanroom. Also, if you are wearing woollen clothes you should remove them before entering the cleanroom in order to prevent electrostatic discharge (ESD) to your work.
  • Once you enter cleanroom entry room, put on a pair of shoe covers. This is done by wearing one shoe cover and swinging the leg over the bench, then covering the other shoe and swinging that as well. You are not allowed to wear uncovered shoes beyond this point.
  • Wear cleanroom hood. Your hair should be fully covered with hood.
  • Wear the coverall, tuck in hood flaps and zip all the way.
  • Put on boots over legs of coverall.
  • Put on safety glasses or goggles. Since chemicals may permeate contact lenses and adsorbed on them, contact lenses are not recommended to use in cleanroom.  Personal glasses including prescription lenses offer sufficient protection.
  • Wear vinyl gloves. Care should be taken not to touch the outside of gloves with bare hands. Pull the gloves over sleeve of coverall.


Once you carry out all the steps in turn, you are ready to enter the cleanroom. Without gloves you shouldn’t touch the door handle, or anything beyond it. The gloves, along with blue inner shoe cover are disposable and therefore should be disposed after use. The garment, on the other hand, can be worn several times. If your gloves are teared or dirty, you can replace them inside cleanroom.

As personal safety measures state, shorts, skirts and open-toed (or open-sided, open-heeled) shoes of any kind should not be worn in cleanroom. It is advised to keep another pair of lab shoes or pants available and worn prior to entering cleanroom. There are lockers available at the entrance of cleanroom. You may request a locker from LS.

In addition, visitors coming with you on an approved cleanroom tour should also follow all the clothing rules of cleanroom and are not allowed to enter cleanroom without wearing the clothes mentioned above. Registered cleanroom user is the main responsible to make sure that visitor is appropriately attired before entering. There will be no exceptions to this rule. Cooperation of all lab users is highly appreciated.

MEL LS should approve a cleanroom lab tour. Requests for cleanroom tour are made in advance. Size of the tour group should not exceed 3 users. For group tours with more than 3 person, please consult to LS.