GLOVE SELECTION

Gloves afford hand protection by minimizing skin contact with the contaminant. However, gloves may often mislead and provide a false sense of security. No one glove can provide protection against all chemicals, so selecting the appropriate glove and knowing its limitations is important.

Glove Selection Considerations

The effectiveness of a glove to protect against chemicals is based on degradation, permeation rate and breakthrough time. Each of these properties must be evaluated to select the correct type of glove. Glove materials are also rated relative to the type of activity—whether you anticipate light, intermediate, or heavy direct contact with chemicals. Glove thickness plays a role in determining breakthrough time. Reusable gloves are generally thicker—offering more protection--than disposable. However, dexterity diminishes with protection level, and reusable gloves are more expensive than disposable. So select gloves based on the type of use (i.e., light/intermittent versus heavy) and the chemical you are using. Few lab procedures call for heavy exposure, though exceptions occur, such as chemical spill cleanups, facilities management operations, and some special research environments.

Degradation, Permeation Rate, and Breakthrough Time

Manufacturers can provide degradation/permeation/breakthrough time charts that list the performance characteristics of a glove material to a given chemical. Degradation is the change in the physical characteristics of a glove caused by contact with a chemical. Degradation may appear as swelling or shrinking, stiffening or softening, discoloration, cracking, or having a rough or gummy surface.

Degradation tests vary with each manufacturer and it is very important to consult each manufacturer’s glove chart. If the chemical has very little degrading effects on the glove material, the manufacturer assigns an “Excellent” rating to the material. Accordingly, “Good”, “Fair”, “Poor”, and “Not Recommended” ratings are assigned depending on the degree of degradation.

The permeation rate and breakthrough time information are also provided in the glove chart. The permeation rate refers to the speed at which a chemical penetrates the glove material. This term is expressed in micrograms per square centimeter per unit or as “Excellent”, “Good”, “Fair”, “Poor”, and “Not Recommended”. The breakthrough time is the elapsed time between initial contact on the outside of the glove with a chemical to the first detection of chemical on the inside surface.

Once a chemical has begun to diffuse into a glove, it will continue to diffuse into the glove material even after the chemical on the surface is removed because of the concentration gradient that develops within the protective glove. Due to this problem, extreme caution is advised when using any chemical protective clothing that has been exposed to highly toxic chemicals. Use disposable gloves with highly toxic chemicals.

The decision on the type of glove material to use is complicated by the variation in glove performance among manufacturers. Chemical resistance, thickness, and length of the glove material, dexterity and worker comfort must be considered before selecting protective gloves.

Inspection and Maintenance of Reusable Gloves

All gloves should be inspected before and after each use, and periodically while in use. The gloves should be examined for holes or punctures, signs of degradation, or signs of prior contamination or breakthrough. If the integrity of the gloves is in question, replace immediately. The outside surface of the gloves should be washed after removal and air-dried in the laboratory. Disposable gloves should be changed as soon as possible after contamination.

Major Glove Types and Uses

GLOVE TYPE / USE
Butyl Rubber / Good for highly corrosive acids, ketones, esters, gases;
Poor for aliphatic, aromatic hydrocarbons, halogenated hydrocarbons, gasoline
Natural Rubber / Good for very dilute acids and bases;
Poor for organics
Neoprene / Good for acids and bases, peroxides, fuels, hydrocarbons, alcohols, phenols
Poor for halogenated and aromatic hydrocarbons
Polyvinyl chloride (PVC) / Good for acids and bases, some organics, amines, and peroxides;
Poor for most organics
Polyvinyl alcohol (PVA) / Good for aromatic and chlorinated solvents;
Poor for water-based solutions- water destroys the gloves!
Silver ShieldTM / Good for wide variety of toxic and hazardous chemicals; provides the highest level of chemical resistance with flexible laminate glove;
Poor fit- comes in small, medium, large
4HTM / Good resistance to many chemicals; better dexterity than Silver ShieldTM
Nitrile / Good for wide variety of solvents, oils, greases, some acids and bases
VitonTM / Exceptional resistance to chlorinated and aromatic solvents;
Good resistance to cuts and abrasions

A few words of warning, no protective glove is totally impermeable. No one material affords protection against all chemicals. For certain chemical mixtures, there are no materials that will protect for more than an hour after initial contact. LATEX GLOVES PROVIDE LITTLE TO NO CHEMICAL PROTECTION IN HEAVY USE CONDITIONS. Consult with EH&S at extension 824-6200 if you have questions or need further assistance.

A good website for selecting the right glove for chemical protection is:

References:

Chemical Health and Safety, November/December 1997, American Chemical Society and ACS Division of Chemical Health and Safety

Personnel Protection and Safety, United States Environmental Protection and Safety, Office of Emergency and Remedial Response, Environmental Response Team

Best Gloves Manufacturing Company, 1-800-241-0323

Pioneer Gloves, 1-800-537-2897

Ansell Edmont Gloves, 1-800-800-0444

4H Glove, Safety 4, Inc., 1-888-401-0400