Disposable gas and toxic fume mask

Abstract

A disposable respiratory protective gas and toxic fume mask is described which comprises a transparent hood of thin film chemical resistant material sealable at the neck or to the face of a subject and covering the eyes, nose and mouth, a filter in the hood for filtering and conducting air into the hood, a tube interconnecting the filter and a mouthpiece and including a first one-way valve for conducting filtered air to the subject, a second one-way valve in the mouthpiece for conducting exhaled air air into the interior of the hood and thereby generating an overpressure condition within the hood.

I claim: 
     
       1. A respiratory protective mask, comprising: (a) a transparent covering for the eyes, nose and mouth of a subject, said covering having a peripheral seal for preventing air leakage around said covering into the region defined between said covering and said subject;   (b) filter means attached to said covering for filtering and conducting air through said covering;   (c) a tube operatively connected at a first inlet end thereof to said filter means and including means defining a mouthpiece at a second outlet end thereof for conducting filtered air to said mouth of said subject;   (d) first one-way valve means disposed within said tube for conducting said filtered air only toward said mouthpiece defining means; and   (e) second one-way valve means included in said mouthpiece defining means for conducting air only from said mouth of said subject and into said region whereby air exhaled by said subject generates an overpressure condition within said region.   
     
     
       2. The mask of claim 1 wherein said covering comprises a hood sized for enveloping the head of said subject with said peripheral seal at the neck of said subject. 
     
     
       3. The mask of claim 1 wherein said covering comprises a chemically resistant thin film material. 
     
     
       4. The mask of claim 1 further comprising a third one-way valve in said covering for selectively limiting the overpressure within said region. 
     
     
       5. The mask of claim 1 further comprising a carbon monoxide oxidation catalyst disposed within said tube. 
     
     
       6. The mask of claim 1 further comprising a water vapor absorbent material disposed on said covering within said region. 
     
     
       7. The mask of claim 1 further comprising an anti-fogging coating on said covering. 
     
     
       8. A respiratory protective mask, comprising: (a) a hood having an opening for receiving and enveloping the head and neck of a subject, said hood including a transparent portion alignable with the eyes of said subject;   (b) an adjustable elastic band on said hood at said opening for resiliently sealing said hood at the neck of said subject for preventing air leakage into the interior of said hood;   (c) filter means attached to said hood for filtering and conducting air through said hood;   (d) a tube operatively connected at a first inlet end thereof to said filter means and including means defining a mouthpiece at a second outlet end thereof for conducting filtered air to said mouth of said subject;   (e) first one-way valve means disposed within said tube for conducting said filtered air only toward said mouthpiece defining means; and   (f) second one-way valve means included in said mouthpiece defining means for conducting air only from said mouth of said subject and into said hood whereby air exhaled by said subject generates an overpressure condition within said hood.   
     
     
       9. The mask of claim 8 wherein said hood comprises a chemically resistant thin film material. 
     
     
       10. The mask of claim 8 further comprising a third one-way valve in said hood for selectively limiting the overpressure within said hood. 
     
     
       11. The mask of claim 8 further comprising a carbon monoxide oxidation catalyst disposed within said tube. 
     
     
       12. The mask of claim 8 further comprising a water vapor absorbent material disposed within said hood. 
     
     
       13. The mask of claim 8 further comprising an anti-fogging coating on said hood.