Liquid Dispensers

18. (1996)

Dispensers or dispensing pumps are used in many laboratories to facilitate the transfer of liquids from stock bottles. These dispensers are commonly used for corrosives, buffers, and other hazardous liquids.

Accidents have recently occurred with the use of dispensing pumps.

In a serious incident, the plunging mechanism of a dispensing pump was pulled out of the barrel, causing the liquid to be sprayed around the room. Two reasons have been suggested for this: a) the tight fitting nature of the teflon plunger made it difficult to move and required more force, and b) a design fault in the adjustment mechanism which allowed it to come free. This dispenser was designed for hydrofluoric acid. It was being tested with water at the time of the incident.

Although dispensers can increase the ease of liquid transfer and reduce risks, remember to consider the following safety points when using liquid dispensers:

• Ensure the stock bottle is appropriately secure.
• Remove the anti-drip plug before lifting the plunger and attempting to dispense liquid.
• Ensure that the plunger/volume adjustment is correctly positioned and secure.
• Never use excessive force on the plunger.
• Handle the stock bottle and dispenser carefully if moving them.
• Don't bump the dispenser.
• Pumps should be initially tested with water prior to use with hazardous liquids.

Additional information is available from the OHS Unit.

For further information contact:
OHS Officer, e-mail: OHS.Officer@anu.edu.au