The present invention is directed to a hood mask for protecting the wearer from chemical and biological environmental contaminants. The hood mask includes a hood having a substantially tubular portion which includes a closed upper end, an open lower end and a continuous side wall having inner and outer surfaces. An air filter assembly is connected to the tubular portion to purify air breathed into the interior of the hood by the wearer. The filter assembly includes a first layer formed of a first member and a second layer including a holder which supports a rigid shell member which houses a second filter member. The holder is formed of a flexible material which as a throughbore in which the shell member is disposed. The first layer and the holder are sealed to one another at their outer edges. The hood mask can be assembled by positioning the first layer and the second layer of the filter assembly adjacent one another and adjacent the tubular portion of the hood mask such that the first layer is interposed between the second layer and the tubular portion, and sealing the first layer and the second layer at their outer edges to the tubular portion by a heat sealing process. A separator member is disposed between the first layer and the second layer in a floating or a non-secured condition relative to the tubular portion of the hood mask.