These are the Breath of Life Mask’s specs, per technonllc. com.
Hood: Five-layer laminate
Filter Layer One and Four: Viscose strengthened by polyester fibers 150 gr/sq- m Contains 0.3% cetylpyridinium chloride (CPC) as an antiseptic that neutralizes bacteria. The first layer acts as a pre-filter against large particles.
Second Layer: The second layer filters particles of 0.3 microns or more, tested for air permeability by the Frazier Air Permeability Method, - 55cfm/sf at ½-inch water gauge.
Third Layer: Polyester nonwoven material at 1.2mm thick and containing active charcoal in a concentration of 114 gr out of a total of 200 gr sq-m - 57% intended to reject air pollution and gas flow, both in dynamic or static conditions.