Reprinted from the ACJ - January, 1994
Did you ever wonder why cartoon characters only have three fingers and a thumb? Take a look at Mickey Mouse or Bart Simpson and you'll see they have no pinkies. My analysis of this leads in two directions. Either they are a step behind us on the evolutionary pathway and haven't developed the pinkie yet or they are the next step in evolution, yielding a more advanced species—Humanis Cartoonis.
Either way, the same quintessential question arises in modern man's mind: "Where do they buy their work gloves?" And do they know what type of gloves are required when handling some of the stuff Wiley Coyote buys from Acme? Here are some of the things to keep in mind when deciding what gloves are appropriate for the jobs in your shop.
First of all, fit is important. Nothing is more frustrating than trying to pick up change while wearing mittens. The same is true of trying to reinstall the locking strips on the Ad-Tech radiator while wearing gloves that have an extra inch of finger. Working with gloves so small that your hand looks more like the webbed foot of a frog is no treat either. Make sure your fingers fit all the way into the glove and webbing is kept to a minimum.
Always wear a glove that allows the most dexterity possible without giving up any protection. Disposable latex gloves like doctors use are excellent for doing intricate work with your fingers, but because they are so thin they rip easily and shouldn't be used in situations where, if they rip, chemicals would contact your hands. Sometimes dexterity has to be relinquished to provide adequate protection. Heat resistant gloves are big and bulky, but I'm not pulling a core out of the header dip pot without them.
The texture of the glove can be important. A grip-type surface on the palm of the glove can come in handy, especially when handling wet items like a core coming out of the test or boilout tank. Oily or greasy parts are also more easily handled with a gripping surface on your glove. The drawback is that the rough surface may cut down on your "feel" through the glove or your ability to manipulate small items easily.
The most important factor when choosing gloves is the resistance to whatever chemical or physical conditions they will be up against. There are more types of gloves out there than we can count on both hands, even if we use our pinkies.
We will discuss a few of the most applicable types. The performance of a glove when tested against a given chemical is judged according to its "Breakthrough Time." That is the time that it takes for the chemical to permeate through the glove and be detected by analytical equipment.
Viton is a substance used for gloves and generally speaking a Viton glove is excellent for water-based acids and bases, but doesn't hold up well in organic solvents like alcohol, acetone and methyl ethyl ketone (MEK).
Another substance often used to coat gloves is PVA. This has excellent chemical resistance, but dissolves in water. You would hate to see your protection go down the drain. PVC (polyvinyl chloride) is also used as a glove material, but a breakthrough time of five hours for hydrochloric (muriatic) acid is reported and they are not recommended for organic solvents like acetone or 111 trichloroethane (a common but increasingly regulated solvent for parts cleaning). Latex gloves as we stated before have excellent chemical resistance, but may tear easily.
Several types of "rubber" gloves are available and prove to be the most viable in a radiator shop application. Nitrile provides protection for oils and alcohols, but protects for only 480 minutes when tested against hydrochloric acid (HCl) and sodium hydroxide (NaOH). The breakthrough time for MEK (a common tank liner solvent) is only six minutes.
Neoprene is the flip side. It is adequate for HCl and NaOH, but has a breakthrough time of 12 minutes for acetone and 27 minutes for 111 trichloroethane. The best choice of gloves for all around use in the shop are those made of butyl rubber. They are recommended for HCl, NaOH, acetone, MEK, 111 trichloroethane, and most fuels and oils. The butyl material has a long breakthrough time for all of these chemicals. They are also rip resistant and give reasonable dexterity.
There are also a number of special application gloves that we will mention briefly. Cotton gloves provide protection from cuts and scrapes and also absorb perspiration from your hands. Used as a liner inside of a chemically resistant glove, they will keep your hands dry.
Kevlar is used in gloves designed for cut resistance. Leather is used by welders for its burn and cut resistance. For higher temperatures, thicker gloves made with Kevlar, Nomex or Zetex are recommended. The heat resistance is excellent, but again they do feel like mittens and may hamper intricate work.
There is a concern when wearing any of the "cloth" type gloves described above. Because the material is absorbent, these gloves should not be used alone when handling liquid chemicals. If the liquid spills on the glove and is absorbed, just like Madge and her dish soap, "You're soaking in it."
Using a chemical-soaked glove is worse than using no glove at all. Remember the dose-time relationship, the longer the chemical contacts your hand the worse the contamination.
This same reasoning can be used when choosing the proper length of the gloves. Use forearm, elbow or shoulder length gloves according to the application. If for some reason the chemical gets over the top of the glove and runs down your arm to your hand, it's the same as soaking your hand in the chemical you're trying to avoid. Get a new pair of gloves right away. Also, if the gloves get a rip or a hole develops, change them. If they aren't intact, they're doing you no good.
The chemicals that permeate or get inside your gloves can cause skin burns, sensitization to the chemical, defatting of your skin or various forms of rashes and dermatitis. Obviously, avoiding these things is why you put the gloves on in the first place. But even if your hands are safely protected in chemically resistant gloves, the sweat from your hands can cause rashes, dermatitis or viral infections like athlete's foot, or is it athlete's hand? That is why an absorbent liner is a good idea.
Some gloves come with a cloth liner or you can use a separate thin cotton glove inside. Switching between several pairs of gloves allowing the sweat to dry inside before using them can also help.
So now we have paragraph after paragraph of words that really boil down to one thing. Keep the chemicals off your hands and you needn't worry about acute or chronic health hazards. Make sure the chemical resistance and physical integrity of the gloves are adequate for the job and no contact will occur. Simple enough. As one of our four-fingered friends would say, That's all Folks!
The above article was written by David M. Brown, Chief Engineer of Johnson Manufacturing Company, Inc. and is published by JOHNSON with the expressed approval of the National Automotive Radiator Service Association and the Automotive Cooling Journal. Other reproduction or distribution of this information is forbidden without the written consent of JOHNSON and NARSA/ACJ. All rights reserved.
JOHNSON MANUFACTURING COMPANY
114 Lost Grove Road / PO Box 96 / Princeton, Iowa 52768-0096
Phone 563-289-5123 or Fax 563-289-3825