Isolating container for live animals

A method for transporting or housing live animals comprising:

• placing the animals in an isolating container comprising a container body and a closure therefor, said container body having an aperture therein through which the animals are introduced, said closure being adapted for attachment to the container body to close the aperture, said body and said closure defining an envelope which totally encloses the interior space within the container when the closure is attached to the body, said envelope comprising means permeable to air and carbon dioxide but impervious to microorganisms so that oxygen may pass into said interior and exhalation gases may pass out of said interior through said air-permeable means without passage of microorganisms into or out of said interior, said air-permeable means comprising a fibrous mat having an apparent density of between about 0.200 g/cm.sup.3 and about 0.400 g/cm.sup.3 and an air permeability of between about 45 and about 200, said mat comprising cellulosic fibers having an average length of between about 0.52 mm. and about 0.72 mm. and an average width of between about 0.018 mm and about 0.024 mm.;
• and
• attaching said closure to said body to close said aperture.

A filter medium comprising a fibrous mat having an apparent density of between about 0.200 g/cm.sup.3 and about 0.400 g/cm.sup.3 an air permeability of between about 45 and about 200, said mat consisting essentially of cellulosic fibers having an average length of between about 0.52 mm. and about 0.72 mm. and an average width of between about 0.018 mm. and about 0.024 mm.

A filter medium comprising a fibrous mat having an apparent density of between about 0.200 g/cm.sup.3 and about 400 g/cm.sup.3 an air permeability of between about 45 and about 200, said mat comprising between about 90% and about 98% by weight of cellulosic fibers having an average length of between about 0.52 mm. and about 0.72 mm. and an average width of between about 0.018 mm. and about 0.024 mm. and between about 2% and about 10% by weight of glass fibers, said glass fibers having an average diameter of between about 6 microns and about 16 microns and an average length of between about 0.25 inch and about 1.0 inch, said mat being substantially free of asphaltic binder material.