ABC of Safety in the Biological Sciences




The pipette is used for measuring and dispensing liquids from one container to another. Designs of pipettes are many and varied, but the same few simple rules apply whichever the form:

  • never pipette anything by mouth
  • always use some type of pipetting aid
  • always use a bio-safety cabinet when pipetting infectious or toxic fluids
  • never expel infectious or toxic materials from a pipette as hazardous aerosols can be created
  • never mix infectious or toxic fluids by alternate suction and expulsion of the fluid through a pipette
  • discharge from the pipette should be close to the surface which receives the fluid
  • always plug pipettes, which are used for infectious or toxic materials, with cotton

Any disposable pipette, glass or plastic, when used with potentially infctious material must be correctly sterilised before disposal. Glass should be disinfected with sodium hypochlorite or similar substance, followed by autoclaving, whereas plastics may be autoclaved then incinerated or buried.

All re-usable glassware must be adequately sterilised as above (when used with potentially infectious material) before being cleaned. All sterilising solutions must be frequently replenished.


Pasteur pipettes are very fragile and are often the cause of inoculation injuries. Wounds must be cleaned rapidly (and disinfected if the substance is potentially infectious). Always seek immediate advice where puncture injuries occur from infected or contaminated pipettes and to ensure that there are no spicules of glass remaining in the wound. Ensure a written record of the accident is kept. If anybreakages occur with glass pipettes, immediately, and carefully clean up the area to avoid contamination from infectious or toxic spicules of glass.

There are many automatic pipetting devices for use with disposable (plastic) or glass pipettes. These must be checked and cleaned regularly to ensure that they have not become contaminated particularly if infectious material is pipetted.


BACK to the top of the Glossary Contents List
BACK to the top of the Chemical Contents List