Table 2 Regulations for BSL-3 and BSL-4 laboratories worldwide.

BSL-3BSL-4
Typical safety
settings		BSL-1/BSL-2
regulations and the
following:		In addition to BSL-3
considerations, BSL-4
laboratories have the
following:
Locking doors with
access away from the
general building.		Dedicated supply and
exhaust air.
Restricted access,
only certified and
trained people,
controlled for 24
hours.		Personnel required to
change clothing
before entering and
shower when exiting.
PPE must be worn, as
well as respirators
depending on
hazards.		Full-body, air-
supplied, positive
pressure suit
depending on the
agent.
Work must be
performed within an
appropriate
biological safety
cabinet (BSC).		A class III BSC.
Sustained directional
airflow and exhaust
air cannot be
recirculated.		Located in a
separated
(preferentially
isolated) area of low
transit.
Examples of
pathogens and
diseases		SARS-CoV, MERS-CoV,
SARS-CoV2, yellow
fever virus, West Nile
virus, prions that
cause BSE,
influenza-A virus
H1N1 flu, avian flu
H5N1, anthrax, TB,
etc.		Ebola, Lassa,
smallpox, Marburg,
etc.
Estimated worldwide
laboratories (21)		>3000>60