Decontamination system

In combination with a work space, which may be contaminated with airborne particles, such as asbestos particles, and which is maintained at subambient pressure, a decontamination system isolating the work space from an ambient space and comprising:

• (a) an inner vestibule, which is connected to the work space via a first portal;
• (b) a first door, which is mounted between the inner vestibule and the work space so as to enable the first portal to be selectively opened and closed by the first door, and which is adapted to allow small amounts of air to infiltrate from the inner vestibule, through the first door, and into the work space when the first portal is closed by the first door;
• (c) a middle vestibule, which is connected to the inner vestibule via a second portal;
• (d) a second door, which is mounted between the middle vestibule and the inner vestibule so as to enable the second portal to be selectively opened and closed by the second door, and which is adapted to allow small amounts of air to infiltrate from the middle vestibule, through the second door, and into the inner vestibule when the second portal is closed by the second door;
• (e) at least one shower bath installed in the middle vestibule for use by personnel entering the middle vestibule from the inner vestibule;
• (f) an outer vestibule, which is connected to the middle vestibule only via a third portal, and which is connected to the ambient space via a fourth portal;
• (g) a third door, which is mounted between the outer vestibule and the middle vestibule so as to enable the third portal to be selectively opened and closed by the third door, and which is interconnected with the second door in such a manner that the second and third portals cannot be simultaneously opened, and which is adapted to seal the third portal against infiltration of air when the third portal is closed by the third door;
• (h) a fourth door, which is mounted between the ambient space and the outer vestibule so as to enable the fourth portal to be selectively opened and closed by the fourth door, and which is adapted to allow small amounts of air to infiltrate from the ambient space, through the fourth door, and into the outer vestibule when the fourth portal is closed by the fourth door;
• whereby personnel whose tools, and garments are contaminated can pass from the work space, through the first portal, and into the inner vestibule, in which they can leave their tools and garments, from the inner vestibule, through the second portal, and into the middle vestibule, in which they can use the shower bath, from the middle vestibule, through the third portal, and into the outer vestibule, in which they can put on clean garments, and from the outer vestibule, through the fourth portal, and into the ambient space, with minimal risk of escape of fugitive particles from the work space via the decontamination system.