Section1
Medical Mycology
Laboratory safety
Dr. Ahmed Abdel-Hadi
There has been a dramatic increase in the number of
guidelines, recommendations, regulations, and standard
introduced for the safety of personnel working with potential
pathogens in clinical laboratories.
It is mandated by OSHA (Occupational Safety and Health
Act, created 1970) that guidelines be implemented and
practiced and that protective clothing, containment devices,
and decontamination equipment and materials be available
in the workplace, procedures regarding biosafety
requirements and practices must be available and familiar to
all laboratory personal.
Code of Practice for Practical Classes
Food and drink must not be taken into or stored in any
laboratory area.
A clean laboratory coat of approved design. It must be worn
fastened and removed before leaving the laboratory area.
Laboratory Coats must be returned at the end of the
Practical Class for autoclaving and laundering.
Students must use other protective equipment, such as eye
protection, gloves, and fume cupboards, as instructed.
CONTAMINATION
Manipulation of organisms should be handled in a user
protective cabinet of approved design wherever possible.
Hands must be washed with bactericidal soap before leaving
the laboratory area, and immediately if microbiological
contamination is suspected.
All potentially hazardous waste to be autoclaved must be
transported to the autoclave in the special leak-proof containers
(autoclave bins or bags) provided for the purpose. All
microbiological waste must be disposed of by autoclaving
whether the organism is considered harmless or not.
Students must be instructed how to dispose of any hazardous
waste they generate. Students must not dispose of any waste
unless they have been so instructed. Hazardous waste must not
be poured down sinks or placed in waste bins.
In areas of benches used for manipulation of microorganisms
should be swabbed down with an appropriate disinfectant at
the end of the working period.
In the event of spillage of microbiological material, it should be
treated immediately by the addition of suitable disinfectant
before mopping up wearing disposable gloves. Dispose of
mopping tissues by placing in an autoclave bag and sealing.
Finally, wipe down the cleaned area with disinfectant, allowing
a 20 minute contact time if bacterial spores are likely to be
present.
Autoclaving is the preferred method of decontamination. Items
to be autoclaved should be labelled with autoclaving tape: Each
load of discards should contain at least one piece of autoclave
tape. Tape only indicates that the autoclave has been heated: It
is the responsibility of the autoclave operator to ensure that an
adequate process is given.
CENTRIFUGATION
Batch centrifugation in capped tubes or bottles may be used
for organisms, but contamination of the rotor should be
avoided by following the manufacturer's instructions and
not overfilling the containers.
If contamination occurs it should be dealt with immediately
by disinfection with isopropanol (not hypochlorite which
will damage the rotor). When centrifuging organisms the
rotor should be disinfected whether or not contamination is
evident.
If centrifuged samples contain microorganisms, the
supernatant should be decanted into suitable leak-proof
containers for autoclaving before disposal.
Centrifuge tubes and bottles must be autoclaved by the
users before washing.
REMOVAL OF CULTURES FROM THE LABORATORY
Any spillage or other emergency must be reported
immediately to the responsible member of staff who will deal
with it in accordance with current Codes of Practice.
Students may not remove anything from the laboratory area
without prior permission.
LABELLING OF CULTURES
All cultures must be labelled with initials, organism and the
date of inoculation.
Cultures of must bear a biohazard sticker. Labels should
conform to the standard described. Old or inadequately
labelled cultures found in incubators or constant
temperature rooms will be disposed .
ACCIDENTS AND OTHER INCIDENTS
All accidents and other incidents, however trivial, should be
recorded in the accident book, and the record should include
details of any possible contamination. Any illness should be
reported to the Centre and your General Practitioner
informed of the materials with which you have been working.
In the event of accidental self-inoculation with
microorganisms, exposure to chemicals, or any splashes in the
eye or ingestion, seek medical advice.
Any cut or abrasion on exposed skin should be protected with
a blue waterproof plaster or plastic gloves. The plaster should
be removed periodically, eg during the lunch break, to allow
the wound to breathe.