Abstract: A moisture and heat exchange device for a regeneration type oxygen self-cained breathing apparatus comprises a casing having pipes of which one pipe is connected to a facepiece of the apparatus and the other pipe is connected to a regenerating cartridge of the apparatus. The casing houses a multiple-layer package of alternating hydrophilic and hydrophobic washers, disposed coaxially with the casing. The hydrophilic washers of the multiple-layer package are made in the form of nets of a fibrous material impregnated with a hygroscopic substance. The hydrophobic washers of the multiple-layer package are made of a non-woven bulk web having a linear density which is lower than the linear density of the material of the hydrophilic washers. Two air-distribution pressure screens are provided at the end faces of the multiple-layer package to engage the hydrophobic washers.

Abstract: A chemical composition comprising oxygenic ingredients and activators whi when activated, generates oxygen for use in breathing mixtures, the oxygenic ingredients being potassium superoxide and sodium peroxide and the activators being aluminum hydroxide, manganese dioxide and powdered aluminum all taken in a proportion as follows, wt. %:sodium peroxide, Na.sub.2 O.sub.2, 10-20;aluminum hydroxide, Al(OH).sub.3, 15-25;manganese dioxide, MnO.sub.2, 5-7;powdered aluminium, Al, 2.5-3.5;potassium superoxide, KO.sub.2, the balance.