Health & Safety: Chemical Protective Gloves

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Health & Safety Committee Conservation Wiki
Copyright: 2013. The Health & Safety Wiki pages are a publication of the Health & Safety Committee of the American Institute for Conservation of Historic and Artistic Works.
Disclaimer: Some of the information included on this page may be out of date, particularly with regard to toxicological data and regulatory standards. Also, because new information on safety issues is continually published, resources outside of AIC should be consulted for more specific information.


Contributors to this page: Kerith Koss Schrager


See the Health & Safety Committee's PPE Chemical Protective Material Selection Guide

Chemical Protective Gloves

As part of a conservator's personal protective equipment (PPE) toolbox, appropriategloves should be available for use with a given chemical. There are a variety of glove materials fromwhich to choose such as nitrile, latex, neoprene, and butyl, in addition totrade name gloves made from multiple materials that provide greater chemical protection.


In addition to chemical protection, the working properties of the gloves, for example flexibility and tear resistance that can vary by material, must also be taken into consideration when choosing the appropriate glove for a task.

Non-disposable gloves usually provide excellent chemical barriers and perform better under mechanical stresses, but tend to be thicker and must be cleaned after each use. Most of these gloves are available in flexible models to address dexterity issues or with slip resistance at the palm and/or fingertips to help with grip.

Disposable gloves are typically thinner and allow for greater movement, but they generally only provide splash protection, may have shorter breakthrough and permeation times, and should be replaced after any chemical contact or after removing them for any reason. Doubling up or combining thinner glove types may lengthen breakthrough time and provide additional physical and chemical protection.


Conservators should also consider using gloves manufactured without the chemicals commonly known as accelerators (i.e., dithiocarbamates,thiurams, and mercaptobenzothiazoles). These chemicals are added to provide elasticity, strength and integrity to the glove material but may cause allergic reaction and potential interactions between the sulfur-containing accelerator chemicals and the artifacts being handled. Manufacturers are aware of the potential negative health effects of sulfur containing accelerators and have developed alternative manufacturing processes in order to provide accelerator-free versions of these products (Ansell 2008).


Technical assistance is always available from glove manufactures and vendors to help determine the correct product for use. A “live” discussion is often best to address specific concerns and samples can usually be obtained upon request. Finally, while MSDSs are vague about the specific glove materials required for use of a particular chemical, the data sheets should be reviewed to assess the overall risk for chemical exposure. Prudent health and safety practices should always be observed to provide a safe working environment.


Glove Types

Supported vs. Unsupported Gloves

Unsupported Gloves are manufactured using hand forms that are dipped directly into a glove compound with no supporting liner. The resulting glove provides good tactility and dexterity.

Supported Gloves are manufactured with a knitted or woven cloth liner that adds structural strength. The liner ensures the gloves have greater resistance to snags, abrasions, cuts, and punctures but affects the tactility.

Generic Materials

Butyl

A synthetic rubber copolymer of isobutylene and isoprene. High permeation resistance to gas and water vapors.

Natural Rubber (Latex)

Latex and natural rubber are often used interchangeably to refer to the type of natural rubber produced from a colloid consisting of polymers of organic isoprene, which is collected from trees and refined into rubber.

Natural rubber latex is very strong and durable and has excellent elasticity and puncture resistance. While providing excellent comfort and fit due to its elasticity and memory, latex contains protein and chemical allergens and can cause severe allergic reaction in some people. Latex is generally low cost but can vary in quality. It easily decomposes in landfills because it is a natural product. Incineration produces mostly water and carbon dioxide.

Neoprene

A synthetic rubber originally produced by DuPont, which is made from the polymerization of chloroprene.

Neoprene has excellent tensile strength and heat resistance. Unbroken neoprene is strong and somewhat puncture resistant; however, once punctured, the film tends to tear easily. Neoprene provides excellent comfort and fit due to its high elasticity and memory. Neoprene is more expensive than latex. It does not decompose in landfills. Incineration produces significant amounts of hydrochloric acid.

Nitrile

A synthetic rubber copolymer of acrylonitrile (ACN) and butadiene.

Nitrile film is highly resistant to punctures and tears. Nitrile provides very good comfort and fit due to its high elasticity and memory. Nitrile is more expensive than latex. It does not decompose in landfills. Incineration produces mostly water and carbon dioxide.

Polyethylene (PE)

A plastic material made from repeating units of ethylene. It does not biodegrade in landfills, but can be photo-degraded. Incineration produces carbon oxides and a multitude of other products.

Polyvinyl Alcohol (PVAL)

A water-soluble plastic made from repeating units of vinyl alcohol. It highly impermeable to gases and water vapor. This glove cannot be used in water or water-based solutions. Polyvinyl alcohol decomposes in landfills. Incineration produces carbon oxides.

Polyvinyl Chloride (PVC or vinyl)

A type of plastic made from repeating units of vinyl chloride.

Vinyl breaks and punctures easily during use. Vinyl elasticity is limited and varies from brand to brand. Low elasticity limits fit and comfort for many users. The wrist diameter is usually very large making the glove baggy around the cuff. Vinyl costs are typically similar to those of latex. Vinyl does not decompose in landfills. The plasticizers in vinyl are hormone analogues. If they leach out into the environment, they can have significant impact on wildlife. Incineration produces significant amounts of hydrochloric acid.

Specialized Trade Gloves

Viton®

Viton® is type of fluoroelastomer, fluorocarbon-based synthetic rubber. Excellent heat resistance. Very flexible, but has minimal resistance to cuts and abrasions.

Viton®/Butyl Rubber

Barrier®

A trade name product of Ansell Pro made from five layers of laminated films. Broad chemical protection with a non-woven polyethylene liner.

Silver Shield®

A trade name product of North Safety Products made from a laminate of polyamide, ethylene vinyl acetate and polyethylene plastic films. It offers a high level of overall chemical resistance, but has virtually no cut resistance.

Ten Important Considerations for the Selection and Use of Chemical Protective Clothing

Adapted from Forsberg, K and Mansdorf, SZ. 2007. Quick Selection Guide to Chemical Protective Clothing, 5th Edition. New Jersey: Wiley& Sons Inc.

1. All chemicals pass or permeate through protective barriers sooner or later. Remember, permeation can take place without any visible evidence or change in the protective materials. Color changes or changes in texture, as well as hardening or softening of protective barriers after use, usually indicate degradation.

2. Even the best protective clothing products will not perform properly if they are torn, cut or damaged. Inspect protective clothing before each use. The integrity of gloves can be checked for leaks by air inflation or by filling with water.

3. A barrier may protect against one chemical very well, but perform poorly against another or a mixture of chemicals. Each chemical and material combination must be considered. No single protective material is an absolute barrier against all chemicals.

4. Recommendations are generally based on tests that have been performed at room temperature. Higher temperature usually decreases the breakthrough time of chemicals.

5. Generally, thicker is better. Increasing the thickness of the protective article will normally increase the time to breakthrough, but the benefits may be offset by a decrease in tactility and dexterity. The use of multiple layers (e.g. double gloving) can increase thickness and provide desirable properties of different materials.

6. Chemical resistant gloves and other chemical protective clothing may all look alike. Be sure that the material you are using is the right one for the job you are doing. Do not depend on only the appearance or color of the material since most barriers are available in many different forms and colors.

7. Once the barrier material has absorbed a chemical, it will continue to permeate (pass through) the material. If the protective material has been contaminated to the point of breakthrough it must be decontaminated or disposed.

8. Many recommendations for glove give the common generic name of the glove material. Most of the polymer formations in each material type vary by manufacturer and can vary from product lot to product lot. Research has shown this variation in chemical resistance can be significant for neoprene, nitrile, and PVC. Users should check with the manufacturer for the test results.

9. Some protective clothing has a shelf life and/or requires special storage measures, such as avoidance of sunlight, ozone, or moisture. Check with the manufacturers for the proper storage, maintenance, and care. Also remember that alterations may void the manufacturer’s warranty and change the performance of the equipment.

10. Very thin ultra-lightweight gloves in rubber and polyethylene often offer poor chemical and mechanical resistance. These types of disposable gloves have much shorter breakthrough times and the ratings from mechanical tests are also typically poor. Natural rubber gloves and gloves produced with accelerators also present a significant problem of allergic reactions.

Regulatory & Testing Standards

OSHA 29 CFR 1910.138(a)(b) Hand Protection

ANSI/ISEA 105-2011 American National Standard for Hand Protection Selection Criteria

ASTM F739 - 12 Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact

Chemical Resistance Guides

Chemical resistance guides or charts provide specific information about the chemical permeability of glove materials and should be consulted when selecting the appropriate glove. Many guides are available, including but not limited to, those listed in the annotated references. However, these charts may present conflicting information because the criteria for testing the different glove types and glove specifications may vary by manufacturer.

Guides can provide recommendations based on permeation, breakthrough time, permeation rates and degradation of the material.


Permeation is the process by which a chemical can pass through the protective material at a molecular or microscopic level. “Chemical permeation can be described in simple terms by comparing it to what happens to the air in a balloon after several hours. Although there are no holes or defects, and the balloon is tightly sealed, the air gradually passes through (permeates) its walls and escapes.” (Ansell)

Breakthrough time (in minutes), the time it takes the chemical to pass through the material and be analytically detected. Breakthrough time represents “how long a glove can be expected to provide effective permeation resistance when totally immersed in the test chemical.”(Ansell)

Permeation rate is the speed at which the chemical moves through the material after breakthrough.

Degradation is the change in one or more physical properties of a glove material due to contact with a chemical. Certain glove materials may change color, become hard, stiff, or brittle, or they may grow softer, weaker, and swell to several times their original size. “If a chemical has a significant impact on the physical properties of a glove material, its permeation resistance is quickly impaired.” (Ansell) However, permeation and degradation do not always correlate.

Penetration, in contrast to permeation, refers to the bulk flow of a chemical through physical spaces in the material such as tears, rips, pinholes and/or manufacturing defects that may or may not be visible to the naked eye.

Manufacturers may use this information in differing ways to define their recommendations and they may also provide data on the performance of materials against national consensus tests and standards. Guides should be read carefully to understand these conditions.


Guides

Ansell Pro SpecWare Online guide allows you to select the chemicals you are interested in and get glove recommendations for both splash and immersion.

Ansell Pro(PDF) This chart contains data for laminate film, nitrile, unsupported neoprene, supported polyvinyl alcohol, polyvinyl chloride, natural rubber, and neoprene/natural rubber blend gloves. Three categories of data are represented for each Ansell product and corresponding chemical: 1) overall degradation resistance rating; 2) permeation breakthrough time, and 3) permeation rate.

Chemrest:Chemical Resistant Glove Directory. "A comprehensive Chemical Resistant Glove Directory powered by Showa Best Glove. Chemrest is designed to inform users about chemical resistance and its relationship to hand protection products manufactured by Showa Best Glove. ChemRest.com offers two major search engines to explore different criteria for chemical resistant gloves.

The Chemical Data Search tool displays test data related to specific chemicals, showing recommended products for any given chemical. Heavy and Limited Exposure test data is available, and Physical Hazards data may also be viewed.

The Chemical Resistant Glove Search explores the physical attributes of gloves such as sizing, color, material, grip texture, length, dexterity and lining. Specific chemicals and exposure requirements may also be selected to display recommended gloves for varying uses.

Additional information about chemical resistant glove manufacturing, testing standards for chemical resistance, and a glove glossary is available for those users wanting more background information on picking the right chemical resistant glove."

Considine, J. Wolfe, K. Posner, and M.M. Bouchard, Conserving Outdoor Sculpture: The Stark Collection at the Getty Center (Los Angeles: Getty Conservation Institute, 2010). This chart provides selection recommendations for a variety of chemicals commonly used in conservation. This type of “best choice” chart may be misleading by suggesting only one material is appropriate for a specific chemical. The user may want to maximize working properties by selecting different glove materials.

Forsberg, K. and S.Z. Mansdorf, Quick Selection Guide to Chemical Protective Clothing, 5th ed. (New Jersey: Wiley, 2007) This comprehensive guide on understanding, selecting and using chemical protective materials contains information for 19 different generic and trade protective barriers and nearly 800 chemicals. The data tables are based on “published and unpublished results of permeation testing completed by accredited test laboratories, manufacturers’ test laboratories, and researchers using ASTM, ISO, and EN standard methods. The majority of the data shown for generic barriers are a summary of the results of more than one test.” (Section IV) Recommendations are based largely on breakthrough times under conditions of continuous exposure. See the Health & Safety Committee's PPE Chemical Protective Material Selection Guide using recommendations from this guide.

Grainger Safety Glove Size Chart This chart helps to determine the correct glove size and length for the task being performed.

North Safety(PDF) This chart contains information on Silver Shield®, Viton®, Chemsoft®, butyl, nitrile and natural rubber gloves. Three categories of data are represented for each North Safety product and corresponding chemical: 1) degradation rating; 2) breakthrough time, and 3) permeation rate.

U.S. Department of Energy (Occupational Safety and Health Technical Reference Manual) This chart rates glove materials by VG: Very Good; G: Good; F: Fair; and P: Poor (notrecommended). However, the source for these ratings and how the ratings were determined is not provided on the website.

H&S Chemical Protective Material Selection Guide

See the Health & Safety Committee's PPE Chemical Protective Material Selection Guide

Glove Vendors & Manufacturers

AnsellPro

Grainger

MAPA Professional

North Safety

Showa Best Glove

Uline

Additional Reading

Ansell Cares. 2008. Chemical Accelerators in Medical Gloves.

Ansell Occupational Healthcare. 2003. Chemical Resistance Guide: Permeation and Degradation Data, 7th edition.

Considine, J., et. al. 2010. Conserving Outdoor Sculpture: The Stark Collection at the Getty Center. Los Angeles: Getty Conservation Institute.

Forsberg, K. and S.Z. Mansdorf. 2007. Quick Selection Guide to Chemical Protective Clothing, 5th edition. New Jersey: Wiley & Sons, Inc.

North Safety Products. 2005. Chemical Safety Guide

U.S. Department of Energy. Occupational Safety and Health Technical Reference Manual. “Chemical Resistance Selection Chart forProtective Gloves.” Reproduced in, Occupational Safety and Health Administration (OSHA),United States Department of Labor. 2003. Personal Protective Equipment




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