ISO 16900-4:2011 specifies the test method for determining gas capacity of separate or integral gas and combined filters for respiratory protective systems. 
ISO 16900-4:2011 includes the validation test at specified flow rates, a desorption test to access the ability of the filter to retain the adsorbed or absorbed gas, and carbon monoxide dynamic testing.


Respiratory protective devices - Methods of test and test equipment - Part 4: Determination of gas filter capacity and migration, desorption and carbon monoxide dynamic testing