Five hidden sources of contamination in the cleanroom


Contamination can come into your cleanroom from places that are often overlooked, it’s hard to predict all of this before it has detrimental effects. Lance Ochs and Jennifer Nunes of the American company UltraTape explain

The purpose of an environmentally controlled cleanroom is to provide a contamination-free space in which to manufacture and/or test products that cannot tolerate even the smallest particles.

Cleanroom classification ratings range from 1 to 100,000 depending on the number and size of particles allowed per volume of air. However, cleanrooms specializing in the manufacture of semiconductors, microelectronics and medical/pharmaceutical devices are among the strictest. Such installations require the implementation of specific processes to reduce all sources of contamination. It also means using products in the cleanroom that are designed to meet specific cleanliness standards.

Contamination can occur unexpectedly with no obvious indication of its origin. This can come from materials and equipment used in manufacturing, people in the clean room, and even consumables such as ribbons or other paper-based products that release particles.

Below are five hidden causes of contamination that can compromise a facility’s cleanroom standards along with approaches to minimize the impact of these sources.


Perhaps the best-known source, most people’s airborne particles migrate out of their cleanroom clothing. Using inappropriate cleanroom attire, not following proper dressing protocol, underdressing for a particular class of facility, or spending too much time between changes of coveralls, gowns, Other clothing or floor mats can all increase particle levels in a clean room.

Particles can escape from even the smallest flaws in cleanroom garments, such as tears, loose fabrics, etc. Routinely using a cleanroom-optimized sealing tape is a simple way to minimize the risk of contamination.

Labels and ribbons

Often overlooked in terms of contamination potential, traditional labels and tapes are an unexpected source of cleanroom contamination, particularly if they are made from paper, have paper cores and/or adhesives that release gases or leave sticky residue. Let’s look at these questions one by one.

Cores: Most ribbon products are made on cardboard cores, which tend to form particles. To prevent particles from forming from the core, use tape rolls that have plastic cores with smooth finishes. This is important because plastic burrs and sharp edges could cut cleanroom gloves or bags, exposing the cleanroom to additional sources of contamination.

Backings and liners: For other ribbons and labels, paper backings or facestocks also cause particles in the cleanroom. Additionally, release liners and paper tend to leave behind particles that could contaminate a clean room. The use of synthetic materials for these uses eliminates the generation of particles.

Packaging: Beyond the use of paper materials in tapes and labels, contamination can even be present in the packaging itself (printed bags, anti-static bags and individually bagged items). For maximum protection, items should be double bagged and properly unpacked inside the facility so that contamination from the outer packaging is not introduced into the cleanroom.

Adhesives: Another source of contamination related to tapes and labels comes from adhesives which can leave sticky residues that can outgas, leaving an invisible layer of contamination in the cleanroom. Chemical contamination is a major concern in the manufacturing of semiconductors and medical/pharmaceuticals; therefore, eliminating any source of off-gassing or adhesive residue is vital. Organic contaminants adhering to the surfaces of silicon wafers, as well as lenses used in lithographic processes, have become a serious problem for manufacturers of chips, medical devices and pharmaceuticals.

All sources of contamination generated by the labels and tapes listed above can easily be eliminated by using residue-free, cleanroom-certified tapes, release liners and packaging from a cleanroom consumable supplier. certified.

Traditional labels and tapes are an unexpected source of cleanroom contamination, especially if they are paper

Process tools

A necessary evil in terms of contamination sources, any equipment intended for cleanroom use must be inspected and cleaned before installation and before each use. Although this requirement seems obvious, its importance cannot be overstated, as close examination of process tools can reveal hidden sources of potential contamination that might otherwise be overlooked.

Monitoring should take place before, during and after use, as tools typically generate airborne gases, volatiles and solid particles during all stages of operation. Constantly evaluating a facility’s equipment and having a plan in place to minimize the impact of these known sources of contamination will have a major positive impact on the cleanliness of your environment.

Raw materials and consumables

Before a raw material or manufacturing product is brought into a cleanroom, it must itself be thoroughly cleaned. Contaminants can hide on packaging or show up if materials and consumables (e.g. face masks, gloves, mats, etc.) are not handled properly. The extent of cleaning required varies depending on the class of cleanroom, the destination of the raw material and the possibility of any cross-contamination with other processes.


Cleanliness standards for maintaining cleanrooms are much higher than for other environments, which means that household and even industrial cleaning products are not enough. In addition to requiring dedicated cleanroom supplies, the cleaning solutions themselves are also purpose-specific (e.g., products that can only be used to clean floors and not countertops). Examples of suitable cleaning products include particle-free wipes and mops, as well as solutions that minimize off-gassing. In addition, vacuum cleaners must have a classification rating equal to or higher than that of the cleanroom in which they are to be used.

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Contamination can come from a range of hidden sources, from the people occupying and working in a cleanroom, to the process equipment and materials used, even to consumables such as tapes and labels. By taking appropriate steps to minimize the impact of these seemingly benign but potentially dangerous sources, you can ensure that the level of foreign object debris in your cleanroom meets or exceeds the specific rating.

Simple but crucial actions, such as securing particulate-free materials and consistently implementing appropriate protocols, will help maximize manufacturing yields and shorten your time to market.