A multi-impregnated filter to a military specification, for removal of hydrogen cyanide gas. Many cyanide compounds will evolve HCN gas if acidified, so this filter is normally specified if working with any cyanide compound. This filter is impregnated with an oxidising agent to oxidise formaldehyde and glutaraldehyde fumes. It is widely used in hospital pathology laboratories and endoscopy units. Diethyl ether is adsorbed on activated carbon, but because of its low boiling point, the local heat of adsorption can reduce the capacity of the filter.
Special impregnation allows a chemical reaction which increases the filter capacity.
As the name implies, this filter is multi- impregnated to a Ministry of Defence specification. It contains noble metals, and is thus rather expensive. This odour filter is normally used in air purifiers to deal with odours from excreta, urine and other materials essentially alkaline in nature. Air purifier odour filters for human and animal acid type smells caused by bacterial decay, such as cadaverine and putrescine, and other odours which are acidic in nature. Molecular Sieve Filter.