Gloves
08/01/2003
Compiled by Steve Smith
Trust your senses when choosing a cleanroom glove
The quest for ever-cleaner operations has never been more focused, especially now that contamination control professionals are setting their sights on the molecular battlefield to combat airborne molecular contamination (AMC). The growing AMC concern is cause for scrutinizing every single material that passes into a cleanroom—including the gloves you use.
Q: What is the basic difference in cleanroom glove materials?
There are basically three variations of glove materials: Latex/nitrile, poly vinyl chloride (PVC) and polyurethane. Latex and nitrile are derived from a chemically activated process. The chemical additives required are the source of the ionic, gaseous, and particle contaminants commonly associated with latex and nitrile. PVC is a plasticized resin. The basic material is the same as that used in PVC pipe combined at a ratio of about 1:1 with plasticizer to make the resin flexible. Unfortunately, the plasticizer also produces very high levels of out-gassing and non-volatile residues. Polyurethane urea, however, is a very high-performance grade of polyurethane. The material gets its extraordinary strength (nearly twice that of latex or nitrile and 4x the strength of PVC) from hydrogen bonding and does not require any chemical activators or additives.
Q: My gloves have an odor. What is it, and is it harmful to my environment?
What you smell is released gasses, or Airborne Molecular Contamination (AMC). The surface of latex and nitrile gloves is chlorinated (a chemical process that removes the natural tack) to allow easier donning. This "case hardened" surface breaks open when the material is flexed or stretched, releasing trapped gasses that are a byproduct of the rubber chemistries. Here's a simple test for your gloves: smell the surface, then stretch the glove a few times and smell again. If you find a smell, or if the smell becomes more pronounced after stretching, then beware, you have found a source of AMC. Many of the released gasses are highly reactive and have been identified as harmful to wafer fabrication and other sensitive device manufacturing.
Q: Why do some of my operators experience redness and itching from their gloves?
With any gloves, hand health is a concern. While mild to serious skin irritation can occur from nitrile and latex gloves, the Center for Disease Control (CDC) and the National Institute for Occupational Safety and Health (NIOSH) report that only a very small percent of the entire U.S population is allergic to latex proteins. More often, it is the surfactants, powders and accelerants, such as carbamates, thiazoles and thiurams used to manufacture these gloves that are the source of irritation. Long-term exposure to these chemicals can increase the threat of sensitization tenfold.
—Information contributed by Wilshire Technologies
Latex/synthetic glove
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The powder-free glove,16-mils thick at the fingertip, is intended for use in trauma situations and the handling of cytotoxic drugs, and has been tested and certified for use in chemotherapy. It has a copolymer interior that provides a combination of copolymer and latex for increased strength, durability and tear resistance. The glove contains 50 micrograms or less of total water-extractable proteins per gram, which reduces the potential for allergic reactions. According to the manufacturer, the multi-layer coating provides comfort against the skin and ease of donning for both wet and dry hands. A micro-rough surface on the fingers and palm enhances sensing and provides a safe grip. The product is 12 inches long and has a beaded cuff.
Sempermed USA Inc.
Palm Harbor, FL
www.sempermedusa.com
Tri-polymer glove
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The TRIonic 521 and 522 are 20 mil, Z-grip, hand-specific tri-polymer gloves that are processed and packaged for critically clean applications, ISO 4 and above. According to the manufacturer, the gloves not only protect the product, they also provide added forearm chemical protection needed in some critical applications.
MAPA AdvanTech
Columbia, TN
www.mapaglove.com
The acid test
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The AciTek acid glove, made from 100 percent latex polymer, is designed to provide flexibility and extended wear comfort, along with protection from a wide spectrum of acids, etchants and solvents. It features an aggressive grip pattern for securely holding glassware, and 13.8 to 14.6-inch length for added forearm protection and secure cuffing. The gloves, tested in accordance with ASTM standards and IEST recommended practices, are especially suited for wafer manufacturing, pharmaceutical/biotech, and general cleanroom maintenance and protection.
Ansell Occupational Healthcare
Coshocton, Ohio
www.ansellpro.com/ce
A hand in the future
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DuraClean with Lycra gloves are designed to exceed current and future critical environment requirements through inherent material cleanliness, no outgassing, low-level ionics, non-cytotoxicity, and re-useability. Billed as "risk reduction tools," the DuraClean and Lycra long-term disposable gloves are made of a proprietary polyurethane polymer that does not cause allergic or skin-irritation reactions.
Wilshire Technologies
Carlsbad, Calif.
www.wilshiretech.com
Re-useable liners
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BCR nylon single-knit glove liners are designed for comfort and protection during extended use in critical environments, and are lightweight, re-useable, and re-launderable. All nylon gloves feature a fiber construction that allows for moisture to be absorbed during wear, and are seamless to keep gloves from unraveling or releasing particles into critical environments.
Berkshire Corp.
Great Barrington, Mass.
www.berkshire.com
Nitrile finger cots
Made from a patented formula, nitrile finger cots do not contain natural latex proteins that may cause allergic reactions. Each washable, anti-static 3-mil cot is rolled to make donning easier, and is available in four sizes.
North Safety Products
Cranston, R.I.
www.northsafety.com
For controlled environments
The CE 4 System glove line (for ISO4 level classification) consists of 12-inch latex and nitrile, sterile and non-sterile, ambidextrous, and hand-specific styles. The CE 5 System (for IS05 level classification) includes 9-inch and 12-inch latex and nitrile ambidextrous gloves. All CE System gloves are tested for physical properties, dimensions, water leak, visual defects, ionic content, particles, and protein content.
Microflex Corp.
Reno, Nev.
www.microflex.com
Extra strength at hand
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Among several recent glove offerings from Techniglove International, the powder-free, 100 percent nitrile X Glove is 8 mils. thick, designed to provide extra strength and protection in the cleanroom. This fully-textured glove offers a secure grip in both dry and wet applications, and promises added protection against abrasions, punctures and tears.
Techniglove International
Yorba Linda, Calif.
www.Techniglove.com
Fully textured, ambidextrous
The Glove Nitrile White, Class 10 process, offers an ambidextrous shape, beaded cuff, and 12-inch length with a fully-textured design for secure gripping. The glove conforms to: Recommended Practice for Cleanroom Gloves; Standard Specifications for Rubber Examination Gloves; Tensile Properties of Vulcanized Rubbers; Accelerated Aging for Latex; and Standard Test for Detection of Holes in Medical Gloves.
Value-Tek
Phoenix, Ariz.
www.value-tek.com