Selecting The Proper Apparel For A Cleanroom Environment

How to pick the best apparel based on job function.

If you work in a cleanroom or sterile manufacturing environment, chances are you wear some sort of protective apparel on a daily basis. But are you wearing the best protective apparel for your job?

The task of selecting personal protective equipment (PPE) should be a team decision involving lab managers, validation engineers, contamination control engineers, quality control engineers, industrial hygienists and purchasing.

The key goal is to limit contamination – anything that is detrimental to yield, productivity, cost, and reliability – of the process or product by people working in the facility. Typical contaminants of concern include bacteria, hair, dead skin cells, clothing fibers and even elemental contamination from sodium, potassium, chloride and magnesium – all of which can be transferred from the human body.

Keep in mind when evaluating and selecting PPE that coveralls, gloves and other PPE accessories are not rated/approved for a specific class of cleanroom. The reality is there are no standards for determining the cleanroom class of a PPE item according to lint or extractable test results. In addition, these test results can be highly variable depending on the type of test and the laboratory equipment used.

Once you’ve narrowed your product selection down to the right group of products, you can choose your PPE based on specific functional needs such as extractables, lint, and ESD properties as well as fit, tactile properties, and material type. Fit can be one of the trickiest issues; what works for a 6ft+ husky man may not work for a 5ft petite woman. The key is to find a balance between a generous fit that will allow a range of motion and a contoured fit that eliminates extra, billowy material, which can cause contamination issues.

Electrostatic Discharge (ESD)
ESD is a particular concern in electronics and semiconductor industries. The goal in controlling ESD is not to eliminate the charge, but to reduce and dissipate it away from the product and to the ground in a controlled manner through the use of wrist straps and static dissipative garments and gloves.

For gloves, the best test of dissipative performance is via In-Use Resistance per ANSI ESD TR-03. Surface resistance testing is not appropriate for gloves because the goal is to dissipate charge through the glove, not along its surface where it can transfer the charge to other components. In-use testing shows both vinyl and nitrile gloves to be static dissipative, having a surface resistivity between 105 and 1010 Ohms. Nitrile contains fewer particles and contaminants that can cause potential damage to products and processes, making nitrile the preferred material for cleanroom applications.

Managing Your PPE
At some point during the PPE selection process, you may be faced with the decision of using a disposable garment or a launderable one. Keep in mind when evaluating the cost of disposables versus reusables, that reusables often contain “hidden” costs associated with managing distribution and collection as well as loss of garment functionality due to degradation of performance (unraveling edges, thinning of material, etc.). Another important caution with reusables is when people try to get multiple wearings without laundering the garments. This can create additional contamination issues relating to the continued “collection” of shedded skin cells and other debris within and on the garment.

Another PPE management issue is sterility in packaging – a particular concern in the pharmaceutical industry, but also of concern in all cleanrooms for moving from one level of the environment to the next cleaner level. PPE should be packaged in such a way that users can extract the PPE from the package and don the PPE without compromising the sterile field. PPE manufacturers typically use multiple packaging layers that are shed as the product is moved from controlled areas to more critical areas. Removing each layer of packaging as the product is moved helps to reduce the possibility of contamination between different cleanliness areas. Look for products with four layers of packaging to allow for optimum transition cleanliness.

Donna McPherson is the Senior Category Manager, Protective Apparel, Kimberly-Clark Professional Safety Division

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