Vibration damage is cumulative, painless while it is happening, and permanent once established, which is a combination that makes it uniquely easy to ignore until the damage is done.

What is actually being damaged

Sustained vibration transmitted through the hands damages the small blood vessels, the nerves and the joints of the fingers and hands. The early signs are tingling and numbness that come and go, and blanching of the fingertips in the cold. Because the earliest stages disappear when the tool is put down, they are routinely dismissed as an ordinary consequence of a hard day. By the time grip strength and fine dexterity are affected, the change does not reverse.

Exposure is magnitude multiplied by time

Daily exposure depends on how much vibration the tool produces and how long the hands are actually on it, and both halves matter. A low-vibration tool used all day can produce a higher exposure than an aggressive tool used briefly. The time that counts is trigger time — the time the tool is running in the hands — not the length of the shift, which is why estimating from the working day massively overstates exposure and estimating from memory usually understates it.

The manufacturer’s figure and the site reality

Declared vibration values come from a standardised test on a specific operation, and real use frequently produces higher values — a blunt bit, a worn chisel, an unsuitable consumable, or forcing the tool all raise the vibration transmitted to the hand well above the declared figure. The declared value is a basis for comparing tools against each other, and a poor basis for calculating an individual’s actual exposure without allowing for site conditions.

What actually reduces exposure

Choosing a lower-vibration tool and keeping consumables sharp are the two largest levers, because a sharp bit does the work quickly and a blunt one converts the extra time into more vibration. After that, rotating the task between people, breaking exposure into shorter periods rather than one long run, and letting the tool take the weight rather than forcing it all reduce the dose. Anti-vibration gloves are the weakest control and can increase exposure, because the padding encourages a harder grip and grip force is itself a major factor in transmission.

Keeping a record that is worth keeping

An exposure record only earns its keep if it captures trigger time rather than shift length, tool by tool, and if it is filled in near the time rather than reconstructed at the end of the week. What makes it valuable is the pattern it reveals: one person consistently accumulating most of the exposure, a particular tool appearing in every high day, or the same task always overrunning. Those are actionable, and none of them are visible from a single day’s entry.

Record it on the vibration and HAVS exposure log, and use the HAVS exposure calculator to work the daily figure. Background is in the hand-arm vibration lecture.

Related standards

The standards below set the test methods and performance levels behind the protective equipment used for this work.

• EN 388 — Protective Gloves Against Mechanical Risks
• EN 352 — Hearing Protectors
• EN 458 — Hearing Protector Selection and Use Guidance

Frequently asked questions