Inhalation toxicology chamber

A multi-level, animal inhalation toxicology research chamber system comprising

• an enclosed airtight chamber having imperforate top, bottom, rear, front and outer end walls and perforate inner end walls spaced inwardly from said outer end walls
• the space between said top and bottom walls, said rear and front walls and said perforate inner end walls defining a central enclosure, and
• the space between said top and bottom walls, said rear and front walls, said perforate inner end walls and said imperforate outer end walls defining vertically extending inlet and outlet plenum means at opposite ends of said chamber
• said inlet plenum means and said outlet plenum means each include three diffusion screens, whereby said inlet diffusion screens are adapted to distribute air in a horizontal direction across said central enclosure, and
• said outlet diffusion screens are adapted to eliminate excess air velocity gradients, thereby maintaining said horizontally distributed air flow across said central enclosure
• a plurality of vertically spaced animal cage support means each extending throughout the horizontal cross section of said central animal cage enclosure adapted to support a plurality of perforate side and bottom laboratory animal cages vertically spaced from one another on a plurality of levels,
• said support means each including upper horizontal perforated shelf means adapted to support said cages and lower imperforate collection pan means,
• inlet means communicating with said inlet plenum means for introducing air into said inlet plenum means
• outlet means communicating with said outlet plenum means for venting air from said outlet plenum means, and
• mixing means connected to said inlet means providing a uniform concentration of contaminant in air introduced into said inlet plenum means for inhalation toxicology research utilizing said animals, said mixing means including
• an air inlet adapted to receive a stream of supply air
• contaminant inlet means adapted to provide one or more different contaminants to said air, and
• a mixing chamber adapted to achieve controlled and uniformed mixing of air with said contaminants and to minimize large particles and agglomerates from the air introduced into said inlet means
• whereby contaminanted air is distributed from said inlet plenum means to said outlet plenum means through said perforate inner walls and said animal cages in a horizontal direction across said central enclosure and
• said imperforate pan means prevents vertical fluid communication between said vertically spaced cages within said central enclosure and said perforated shelf means permits vertical passage of animal waste into said collection pan means for collection therein,
• thereby preventing animals from contacting their own waste and preventing waste from falling on animals located beneath an upper cage.