Cleanroom apparel has two major functions. It protects the controlled environment and the products from human contamination. It also protects the cleanroom personnel from harmful products or materials. For these reasons, the apparel should have the following properties:
- Shed very little or no particles
- Easy to put on and comfortable
- Easy to clean and dirt repellent
- Stand sterilization and washing
- Sturdy and break-up resistant
Without suitable apparel, cleanroom apparel can be a major source of contamination. For instance, NASA’s Hubble Space Telescope failed to perform as was expected due to particles that were 200 times smaller than a human hair.
What is cleanroom apparel?
This refers to any form of clothing or related covering material which is worn in a cleanroom environment. It includes: coveralls, coats, trousers, hair covers, gloves, face masks, goggles, boots, and shoe covers. Low-level cleanrooms may only need a few apparel items such as special boots that will not track in dirt or dust. In a high-level controlled environment, personnel may need to put on a bunny suit or an all-in-one coverall.
The science behind cleanroom apparel
It is difficult to ensure that the contamination levels in a controlled environment stay below the acceptable threshold. The machinery, equipment, tools, and the air in the controlled environment harbor pollutants. However, the biggest source of contamination is the cleanroom personnel. Unlike tools and equipment, it is impossible to sterilize humans completely. For this reason, controlled environment personnel continually emit hairs, dead skin, and microbes, among other pollutants into the air. This makes it necessary to wear garments that will hinder contamination as well as protect the wearer.
Factors to consider when choosing your cleanroom apparel
The first factor you should consider when selecting appropriate cleanroom apparel is its class. In high-level controlled environments, personnel needs to be fully covered to minimize the chances of body contamination. For example, employees working in ISO class 5 controlled environments need to put on their coveralls, hoods, boots, gloves, masks, and goggles. On the other hand, those working in ISO class 8 environments only need to cover their hair, faces, normal attire, and shoes.
You also need to consider the apparel fabric. Make a choice based on its weight, filtering ability, weight, breathability, comfort, strength, and durability. Some of the most common apparel fabrics for controlled environments include:
- SMS – these apparels are also made of polypropylene, but they have three layers rather than one. Such apparel is made by sandwiching a layer of melt-blown PP between two of spunbound PP. This results in extremely durable, breathable, liquid-resistant, and low-linting
- Microporous – microporous controlled environment apparels are made using PP laminated with a polyethylene layer. These apparels will provide you with the highest durability. They are perfect for high-level controlled environments
Different controlled environments have varying operating procedures. For instance, some may require their personnel to change their garments weekly. Others require them to use theirs for some time. If the personnel work in a controlled environment where they have to change their apparel frequently, disposable apparel is the most suitable option. You also need to consider the static charge generated by your controlled environment apparel. For example, fabrics that generate high static charge should not be used in electronic component manufacturing industries or explosive atmospheres. Cleanroom garments with a high static charge are also likely to attract contaminants and bacteria.
Along the same line, OSHA regulations demand that controlled environment personnel wear clothes that are flash-flame-resistant if they work in a setting where the threat of such is prevalent. In that case, you will need to invest in flame-resistant (FR) labeled controlled environment apparel. You need to choose controlled environment fabrics that are compatible with other accessories, including face masks and gloves.
Sterile vs. clean and sterile cleanroom garments
While these terms might appear interchangeable, they are completely different as far as the controlled environment is concerned. Sterile apparel could be manufactured in any facility. After the manufacturing process, the garments go through a sterilization process through gamma radiation. Sterile controlled apparels are not usually clean-processed. For this reason, they are prone to introducing foreign particles into your controlled environment. On the other hand, clean and sterile clothing is manufactured in a clean and controlled manufacturing environment. This means that such garments are manufactured in a by operators who do not add contaminants onto the apparel during the manufacturing process.
Cleanroom garment construction
The sole purpose of controlled environment apparel is to contain the wearer’s contamination. Therefore, they should not be a source of contamination. Rather, they should be constructed in a way that ensures that this goal is achieved.
The apparel should have no fabric edges. All seams need to be lapped or bound. Apart from containing the contaminants from the edges, such seams prevent free air passage (and thus contamination) from the apparel’s inside into the controlled environment. Features such as pleats, pockets, and so on should also be avoided during construction. The fabric must be comfortable to wear, non-linting, and static dissipative or anti-static. Non-linting fabric does not release particulates into the critical environment. They should be well-fitting to enable the personnel to fasten cuffs and collars as they should.
Controlled environment garments should be evaluated for particulate emission. Also, consider the processes the garments will go through in the course of their lifecycle. These processes go beyond basic laundering to sterilization processes such as autoclaving or gamma radiation. These have a negative effect on the apparel’s lifespan and performance efficiency. Controlling human contamination in a cleanroom can be quite difficult. Although proper gowning techniques could significantly reduce the probability of contamination, you need to invest in appropriate apparel. International EnviroGuard provides you with a wide range of disposable controlled environment apparel suitable for ISO 5 through ISO Class 9.
- MicroGuard CE® - suitable for environments that do not require sterile garments. These apparels have been tried and tested for various industrial chemicals. They feature a tunnelized elastic which enabled particulate containment. They are available in a clean-processed single packaging.
- GammaGuard® CE – these are suitable for critical environments. They are low-linting as well as tear-resistant. They are packed individually and clean-processed. The entire product range is sterilized to a 10-6 SAL.
Confidence in your controlled environment begins when you understand how to select the most suitable fabric for your space. International EnviroGuard is a well-established manufacturer of controlled environment apparel. We will be happy to walk you through the various options and answer all your queries regarding our cleanroom apparel manufacturing process. All our products are made in ISO-certified manufacturing plants.