Injury caused by agitator in laboratory

Hair pulled out by laboratory stirrer

Although it is well-known that power-operated agitators represent a dangerous trap, the agitators in the laboratory were not cladded as per the requirement or, where the cladding was mounted, was not matched to the height of the container, and as a result the agitators were running in the open – at a drive power of 500 to 1000 W. Furthermore, the on/off switches of the stirrers were mounted on the wall behind them, meaning that the operator needed to reach between the stirrers, which were installed quite closely together, each time he wished to use a switch. In doing so, he was unable to avoid reaching into the danger zone.

And so the inevitable happened: the agitator grabbed the hair of an employee and began to wind it up. Only the fact that the hair on one side of his head was torn out prevented the employee from being scalped. However, he lost nearly all the hair on half of his head.

Cladding of the agitators using solid pipes is a suitable solution when the stirrer tanks can be kept at a standard height; otherwise, telescopic tubes or bellows can be used, which must then be matched to the container size. Only at motor powers of no more than 300 W is it possible to deviate from these measures. Further measures include the regular briefing of employees on the basis of operating instructions and the coordination of clothing, jewellery, hair style and personal protective equipment (no (!) gloves may be worn) in the workplace, so that another such accident does not have more serious consequences in the future.

See: Sichere Chemiearbeit 11-1992, 143