Case study: a brewery where the danger was impact noise

The site

A cask- and keg-ale brewery in the West Midlands, where the noisiest work is racking (filling) and keg washing — moving, washing, bunging and re-loading steel kegs. We measured the key tasks and areas to Class 1 standard and calculated exposure for the racking and keg-washing groups.

What we found

Every measured task in the racking and washing area sat at or above the 85 dB(A) upper action value, with keg re-loading and bunging the worst at 100.1 dB(A). The two exposure groups' daily personal exposures worked out at about 96 dB(A) (keg washing) and 92 dB(A) (racking). But the striking figure was the peak: keg handling produced a 134.3 dB(C) impulse — just 0.7 dB below the 135 dB(C) peak action value.

The insight that pays for the survey

Unusually, the brewery's problem is impact noise, not steady machinery. The loudest events come from steel kegs being dropped, rolled and bunged — metal on metal — which is why the peak sits right on the edge of the action value while the machines themselves are unremarkable. That points to a strikingly low-tech fix: rubber or HDPE contact strips, damped guides and resilient pads on the surfaces kegs land on, plus controlled placement instead of dropping. Softening the contact points takes the top off both the peaks and the daily dose — far cheaper than enclosing plant, and it wouldn't have been obvious without measuring the impacts.

What the client got

• Mandatory Hearing Protection Zones across the racking and keg-washing tasks, with a communication-capable protector (nominal SNR 25) bringing the level at the ear to about 74–77 dB(A) — safe, but still able to hear the yard and vehicles.
• A practical impact-reduction plan — rubber/HDPE contact strips, damped guides and controlled keg handling — targeting the source of the loudest events.
• A recommendation to confirm real time-at-task so exposures are pinned to actual working patterns, plus audiometry for the exposed staff and a verification survey after the changes.

That is the difference between a survey that just says “you're over the limit” and one that tells you exactly where to act — and keeps it current, which is what the 4-Year Care Plan is for.