Chemical protective clothing should not be considered as a replacement for engineering control methods. However, there are often few alternatives available, or an emergency (e.g., a spill) requires their use. Since the clothing is the last line of defense for protecting the skin, care must be taken to ensure it provides the protection expected.
The phrase commonly found on the Material Safety Data Sheet (MSDS) "Wear impervious (or impermeable) gloves" has very limited value. It is technically inaccurate. No glove material will remain impervious to a specific chemical forever. No one glove material is resistant to all chemicals. Some chemicals will travel through or permeate the glove in a few seconds, while other chemicals may take days or weeks.
Information specifying the best type of chemical protective material is what should be on the MSDS (e.g., neoprene, butyl rubber). If this information is missing, contact the supplier or manufacturer of the product. Manufacturers of chemical protective gloves and clothing may also assist their customers in making the appropriate choices.
Permeation rate is the rate at which the chemical will move through the material. It is measured in a laboratory and is expressed in units like milligrams per square meter per second (or some other [weight of chemical] per [unit area of material] per [unit of time]). The higher the permeation rate, the faster the chemical will move through the material.
Permeation is different from penetration. Penetration occurs when the chemical leaks through seams, pinholes and other imperfections in the material: permeation occurs when the chemical diffuses or travels through intact material.
Breakthrough time is time it takes a chemical to permeate completely through the material. It is determined by applying the chemical on the glove exterior and measuring the time it takes to detect the chemical on the inside surface. The sensitivity of the analytical instruments used in these measurements influence when a chemical is first detected. The breakthrough time gives some indication of how long a glove can be used before the chemical will permeate through the material.
Degradation is a measurement of the physical deterioration of the material due to contact with a chemical. The material may get harder, stiffer, more brittle, softer, weaker or may swell. The worst example is that the material may actually dissolve in the chemical.
Based on the above information, it becomes apparent that you must carefully choose the appropriate material for each job. Before deciding about which kind of glove or other chemical protective clothing to use, you should gather and analyze information on a number of factors such as:
Suggested materials should be selected based on quantitative information such as permeation rate, breakthrough time, penetration and degradation, and the other considerations mentioned above. Various factors like the thickness of the material, manufacturing methods, and product quality control can have a significant effect on these properties.
For a few specific situations when it is impossible to predict the variety of hazards, multilaminate gloves made of layers of several different materials are available.)
|Guide to the Selection of Skin Protection|
|Hazard||Degree of Hazard||Protective Material|
|Abrasion||Severe||Reinforced heavy rubber, staple-reinforced heavy leather|
|Less Severe||Rubber, plastic, leather, polyester, nylon, cotton|
|Sharp Edges||Severe||Metal mesh, staple-reinforced heavy leather, Kevlar® aramid-steel mesh|
|Less Severe||Leather, terry cloth (aramid fiber)|
|Mild with delicate work||Lightweight leather, polyester, nylon, cotton|
|Chemicals and fluids||Risk varies according to the chemical, its concentration, and time of contact among other factors. Refer to the manufacturer, or product MSDS.||Dependant on chemical. Examples include: Natural rubber, neoprene, nitrile rubber, butyl rubber, PTFE (polytetrafluoroethylene), Teflon®, Vitom®, polyvinyl chloride, polyvinyl alcohol, Saranex™, 4H®, Chemrel®, Responder®, Trellchem®|
|Cold||Leather, insulated plastic or rubber, wool, cotton|
|Heat||High temperatures |
(over 350 deg C)
|Medium high |
(up to 350 deg C)
|Nomex®, Kevlar®, neoprene-coated asbestos, heat-resistant leather with linings|
(up to 200 deg C)
|Nomex®, Kevlar®, heat-resistant leather, terry cloth (aramid fiber)|
|Less warm (up to 100 deg C)||Chrome-tanned leather, terry cloth|
|General Duty||Cotton, terry cloth, leather|
|Product Contamination||Thin-film plastic, lightweight leather, cotton, polyester, nylon|
|Radiation||Lead-lined rubber, plastic or leather|
Note: The mention of trade name products in the above table is not intended as a recommendation or endorsement of any product. Checking on any TM will take you to the web page "Personal Protective Clothing - Trade Names & Manufacturers". This document lists trade names of protective clothing material mentioned in OSH Answers, the name of companies to which the trade names are registered, and a brief description of the protective clothing material. Check with your supplier or the manufacturer to find out if a particular glove meets your requirements. This list is not intended to be comprehensive; you may know of other products that meet your needs.
Since there are many hazards, hand protection can be provided in a variety of ways: finger guards, cots and thimbles, hand pads, mitts, and gloves.
The selected glove should be carefully tested in the actual job conditions. In some situations it may be desirable to do laboratory tests on the gloves using American Society for Testing and Materials (ASTM) methods. This is especially important if you do not have information of the permeation time of a particular chemical you are using or if you are using mixtures of solvents or chemicals. Some glove manufacturers may undertake these tests for their customers.
A process needs to be in place to ensure a competent person reviews the selection and use of chemical protective clothing. If chemical protective gloves and clothing are required, there should be a complete program in place that includes
A successful program will ensure that any changes in chemicals being used are accounted for, will uncover any problems and will result in necessary changes or improvements.
Unfortunately, chemical protective clothing are often considered as a fast and easy method of providing skin protection. The long-term costs of setting up and maintaining a chemical protective clothing program may be higher than the costs for implementing proper engineering controls. In addition, even with the use of gloves, the risk of contact with the chemical still remains. However, in many situations, when the engineering controls for enclosing hazardous chemicals are not practicable, a chemical protective clothing program becomes essential for the protection of workers.
Since personal protective equipment such as gloves are the last line of defense, considerable effort should be expended to ensure that adequate protection is actually being provided.
Many manufacturers of chemical protective clothing provide charts and computer software to help in selecting the appropriate gloves when working with a chemical or a specific mixture. In addition, there are various glove-material compatibility charts and other glove selection aids available from independent sources. However care must be taken in interpreting generic information, since the properties, thicknesses, and quality assurance of glove materials may vary between manufacturers.
For solvent mixtures, however, tests may have to be carried out if data are not available of the specific mixture. The reason for this is that the properties of the mixture, especially permeation time, cannot be predicted by using data from the individual components of the mixture.
Protective clothing has been recommended for some materials on our web site. Please refer to Chemical Profiles in the Chemicals and Materials section for information on some selected chemicals. The CCOHS database CHEMINFO also has occupational health and safety information such as recommendations for chemical protective clothing for some 1,300 chemicals.
Document last updated on August 17, 2009