I’ve never been a fan of wearing work gloves, personally, probably because I can never find gloves that fit me properly. I always have flaps of fabric at the ends of my fingers. If a glove slips off my hand when I pull on something, like a weed in the garden, I’d rather work barehanded. My large-handed colleagues are more concerned about gloves that are too small, but I’m still wearing the gloves and mitts that my kids grew out of years ago.
I rarely work with power tools at home, so I’ve never needed a work glove to protect my hands from vibration. A client recently asked how well gloves protect from vibration, so I thought I’d do some research about gloves. If you’re not familiar with the effects of vibration, let me summarize very briefly: prolonged exposure to hand-arm vibration can damage the blood vessels in the hands, causing what is known as “vibration white finger.”
I found this position paper from CRE-MSD, which provided some great advice about gloves in general. If you’re selecting gloves to protect from chemicals, temperature, cuts, or biohazards, I recommend reading this paper first. Regarding vibration, Dr. Wells recommends that you “choose International Standard Organization (ISO) approved anti-vibration gloves that reduce transmission at the relevant frequency”. He pointed out that anti-vibration gloves reduce vibration transmission by about 20% more at the fingers than at the palm.
Let’s focus on the “relevant frequency” part of Dr. Wells’ recommendation. Frequency refers to how fast something is vibrating, in units called Hertz (Hz). To measure the frequencies your tools are humming at, you need special equipment. However, the Health and Safety Executive (HSE) published some very useful resources for evaluating vibration for new tools. The ISO has set out a procedure for testing a glove’s vibration transmissibility, or transmission rate (TR).
How to pick the right glove for the tool’s frequency
This “frequency” thing adds another level of complexity to the selection. I went looking for specifications about what frequencies were being absorbed by various glove types, and found….not much. This paper, by researchers at NIOSH in the US, suggests that AV gloves absorb more of the higher frequency vibration (like that produced by chipping hammer or reciprocating saw), and less of the lower frequency vibration (e.g. pavement tamper). A glove that meets the ISO 10819 standard must be certified, and to obtain the certification, it must have a TR for medium frequencies (TRM) of less than 0.90, and a TRH of less than 0.60.
I searched online for TR values and found that some vendors report them, but most don’t, and it isn’t always obvious if the gloves have even been tested. Glove manufacturer Impacto Protective Products includes some product flyers which report the transmission rate for the specific glove. In the linked example, TRM is 0.871, and TRH is 0.542. I’ve found that our clients’ vendor sales reps are incredibly helpful if you ask questions, so if vibration is a concern at your workplace, dig a little deeper to ensure that you’re protecting workers effectively.
More tips for reducing vibration exposure:
Another research paper by Budd and House (2017) offered a few other useful points:
1. Stance
A worker in an unstable stance will grip the tool with more force, and will therefore be exposed to more vibration. (Think about the difference between standing on concrete and standing on a hill in the snow.)
2. Glove thickness
Thicker gloves absorb vibration more effectively, but are heavier, reduce dexterity and grip strength, and may increase fatigue.
3. Fatigue
If the hands become tired, the worker will grip the tool harder, thereby increasing vibration exposure and compounding fatigue.
4. Heat
Gloves prevent heat loss, and warm, dry hands are less likely to experience Hand-Arm Vibration Syndrome.
Not to overstate the obvious, but tool maintenance also helps to minimize vibration exposure. The amplitude (the “size” of the wave) gets larger as the tool, bits, extensions, and sockets get worn out.
As a small person, I’m sensitive to issues of fit, but it bears repeating that if you’re providing only a few sizes of gloves, you won’t be accommodating workers of all sizes. A glove that is too big will slide around on the hand and cause the worker to grip tighter, and will limit dexterity. A glove that is too tight will create resistance to gripping and increase grip effort, and will restrict circulation, compounding the circulatory problems associated with hand-arm vibration. Choose gloves that are available in sizes that will fit ALL of your workers. Apply pressure to manufacturers to expand their size offerings. “Medium” is not “small enough”. If we don’t demand the full range of sizes, they’ll only make what sells best.
In summary, yes, anti-vibration gloves can reduce the risk associated with prolonged exposure to hand-arm vibration. Look for the ISO certification, and try to ensure that the gloves will effectively absorb the frequency that the tool is emitting. Make sure the gloves are available in the full range of sizes to accommodate your workers. If you’ve hired someone my size, you’ll probably need to offer child-sized gloves 😉.
Need some help evaluating alternative gloves or other tools, products, or devices? Our ergonomists would love to help you with comparisons and objective product trials. Give us a call (519-6232-7733) or email info@taylordergo.com.