Abstract: A process is provided for preparing fibrous or film type activated carbon including the steps of carbonizing a cellulosic material and activating the resulting carbon, each stop occurring at a temperature between 200.degree. C. and 1100.degree. C. in an oxidation-suppressing atmosphere, in which, prior to activation, the cellulosic material or carbon is impregnated with at least one boron-containing compound and at least one phosphorus-containing compound. This impregnation treatment greatly increases the activation rate, so reducing the activation time and therefore energy costs. Higher levels of production of fibrous activated carbons can thus be achieved.

Abstract: A heat and smoke protective hood comprises a bag-like head covering 1 of a heat-resistant, substantially gas-impermeable sheet material adapted to fit loosely over the head of a user, filter means 5 in an aperture 6 of the head covering to remove harmful ingredients from inhaled air, a stretchable annular neck portion 2 attached around the open end 3 of the head covering to form a seal around the user's neck, and a flexible annular skirt 8 of heat and flame resistant material attached around the circumference of the head covering so as to hang down around the neck portion and user's neck to protect both. Preferably, the skirt 8 also covers the filter means 5.