When entry restrictions
are necessary, a hazard warning sign incorporating the universal
biohazard symbol should be posted on all access doors to the
This sign should identify the infectious agent(s) currently
used, list name and telephone number of the responsible supervisor,
and define specific requirements for entering the area.
As inadvertent ingestion is a realistic means of exposure
to microorganisms, supervisors should prohibit eating, smoking,
This prohibition should also be extended to the application
of cosmetics in the laboratory. Nail biting is strongly
discouraged, as this is another means of exposure to hand
Clearly, mouth pipetting is not to be permitted. Mechanical
pipetting devices are required. These devices are more
accurate than standard pipettes and eliminate aspiration/ingestion
as a source of laboratory-acquired illness.
Hand washing provides another means of preventing ingestion
of organisms and their spread to other surfaces. Hands
should be washed after working with infectious microorganisms
or cleaning up a spill.