86 
The following safe microbiological practices and laboratory techniques 
apply to all experiments requiring P4 level physical containment: 
a) The universal Biohazard sign is posted on all facility access 
doors and all interior doors to individual laboratory rooms 
where experiments are conducted. Only persons whose entry 
into the facility or individual laboratory rooms is required 
on the basis of program or support needs are authorized to 
enter. Such persons are advised of the potential biohazards 
and instructed as to the appropriate safeguards to insure 
their safety before entry. 
b) Personnel enter into and exit from the facility only through 
the clothing change and shower rooms. Personnel shower at 
each exit from the facility. The air locks are not used 
for personnel entry or exit except for emergencies. 
c) Street clothing is removed in the outer facility side of the 
clothing change area and kept there. Complete laboratory 
clothing, including undergarments, pants, and shirts or 
jumpsuits, shoes, head cover, and gloves, are provided and 
used by persons who enter the facility. Upon exit, this 
clothing is discarded into collection hampers before personnel 
enter the shower area. 
d) Supplies and materials to be taken into the facility are placed 
in an entry air lock. After the outer door (opening to the 
corridor outside of facility) has been secured, personnel 
occupying the facility retrieve the supplies and materials 
by opening the interior air lock door. This door is secured 
after supplies and materials are brought into the facility. 
e) Doors to laboratory rooms within the facility are kept closed 
while experiments are in progress. 
f) Experimental procedures requiring P4-level physical contain- 
ment are confined to Class III Biological Safety Cabinets. 
All materials, before removal from these cabinets, are 
sterilized or transferred to a sealed durable container, 
which is then removed from the system through a chemical 
decontamination tank, autoclave, ultraviolet air lock, or 
after the entire system has been decontaminated. 
g) No materials are removed from the facility unless they have 
been sterilized. All wastes from the Class II Biological 
Safety Cabinets and other materials to be reused (e.g., soiled 
laboratory clothing), discarded (e.g., trash), or removed from 
the facility are sterilized in the double-door autoclave. 
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