The Most Common Sources of Contamination in Cleanrooms

Unexpected contamination can occur without a readily evident source.

Fremont, CA: The goal of an environmentally controlled cleanroom is to provide a space free from contamination where products that cannot tolerate even the smallest particles may get made and tested.

Cleanroom classification ratings range from 1 to 100,000 depending on the number and size of particles permitted per cubic of air. However, producing microelectronics, medicines, and medical devices places the highest demands on cleanrooms. To eradicate all sources of contamination in these facilities, specific processes must get followed. Additionally, using equipment designed specifically for cleanrooms and adhering to stringent standards of cleanliness is required.

Unexpected contamination can occur without a readily evident source. It can originate from consumables, including tapes or paper-based items that drop particles, manufacturing tools and materials, workers in the cleanroom, and even individuals.

The top covert sources of contamination that might jeopardize a facility's cleanroom requirements are listed below, along with methods to lessen their influence.

• People

Most airborne particles from individuals move out of their cleanroom clothing, making them arguably the most well-known source. However, particle levels in a cleanroom can get raised by using incorrect cleanroom clothing, failing to follow proper gowning protocol, gowning insufficiently for the facility class, and waiting too long between changes of suits, smocks, other clothing, or floor mats.

Even the tiniest flaws in cleanroom clothing, such as rips, loose fabric, etc., can allow particles to escape. One easy method to reduce the chances of contamination is to use cleanroom-optimized cuff sealing tape consistently.

• Labels and Tapes

Traditional labels and tapes, which are sometimes disregarded in terms of their potential for contamination, are an unexpected source of cleanroom contamination, particularly if they are composed of paper, contain paper cores, and have adhesives that outgas or leave a sticky residue.

• Process tools

All equipment helpful in a cleanroom must be examined and cleaned before installation and each usage, which is a necessary evil concerning contamination sources. Even though this criterion appears simple, it cannot get overstated since careful examination of process equipment might discover hidden sources of possible contamination that could otherwise go unnoticed.

Since tools often produce gases, volatiles, and solid airborne particles at all stages of operation, monitoring should be done before, during, and after usage. The environment will be much cleaner if users regularly assess the equipment in the business and have a plan to reduce the effect of these known sources of pollution.

• Raw materials and consumables

It is necessary to properly clean the raw materials or manufactured products before bringing them into a cleanroom. Contaminants may be present on the packaging or develop from improper handling of products and consumables (such as face masks, gloves, mats, etc.). Different levels of cleaning are necessary depending on the type of cleanroom, where the raw materials are going, and whether there is a chance of cross-contamination with other operations.