Evaluation of materials proposed for use in space flight

The primary irritancy and allergenicity of flame resistant treated cotton knit shirts proposed for use in space flight were evaluated. The knitted shirts were supplied by NASA as follows: knitted shirts with collars were made of two-ply mercerized single-knit cotton jersey. The fabric was treated with tetrakis (hydroxymethyl) phosphonium hydroxide and subsequently cured with gaseous ammonia (THPOH/NH3). The final treatment comprised adding on diammonium phosphate (DAP)/urea. The treated fabric was process scoured to remove extraneous materials, top softened and mechanically or chemically finished as required for specific needs. Diammonium phosphate is a more efficient flame inhabitant than the phosphonium; thus, the combination treatment served to impart higher resistance to ignition and sustained combustion as required by NASA test standard.