// FILTRATION
This is the most important function of laser fume extraction systems. Most modern systems incorporate a series of filters that purify the fume in stages. With regards to the filters, almost all systems on the market use a standard format consisting of a pre filter, micro or HEPA filter and often a chemical barrier.
Laser fume filtration must be fairly clever in it application because the range of particulate and gas in any given fume can be made up of say 90% particulate 10% gas, or visa versa. Add into the equation acidic hydrochloride or highly toxic phosgene which has a maximum exposure of 0.08 mg/m3 and the requirements become focused.
On a general scale a laser fume will contain particles ranging from 1-2 microns down to 0.1 micron. If a micro filter which captures 99.997 of all particles down to 0.1 micron were used on its own, it would not take long to clog with larger particulate.
