The HJ3100 Fume Extraction System is available with a HEPA/carbon filter as a standard but can also be used with an Activated Carbon filter. The HEPA/carbon filter is used primarily in soldering applications where particles as small as 0.3 microns are created primarily from the vaporized flux. HEPA filters allow only very small particles to pass through. The Activated Carbon filter can adsorb a wide variety of substances, i.e. they are able to attract molecules to their internal surface, and are therefore called adsorbents.

HEPA filter

American Hakko’s HEPA/carbon filter (P/N 999-137) purifies the air by removing particles as small as 0.3 microns. The filter is designed for use in removing the fumes generated from soldering applications. The HEPA filter is a particulate filter that incorporates a pleated fiberglass paper medium, thus providing the greatest amount of surface area within the volume of the filter case. It is rated as a 'hospital grade HEPA filter' - greater than 98% efficiency per the DOP test - and removes particles as small as 0.3 micron. The filter also contains a thin activated carbon filter that adsorbs gases and odors from the filtered air. Adsorption efficiency is 80%. A prefilter (999-136 or 999-201) is required.

Soldering work involves both metallic and organic compounds. The solders themselves contain, tin, sometimes lead, various levels of zinc, arsenic, cadmium, antimony as well as other metals. Fluxes necessary for soldering contain activators to enhance their cleaning properties; these activators are typically organic acids. Such compounds, when heated, release byproducts of incomplete combustion, which in turn can contain noxious fumes, particulate matter, aerosols, and gasses. Prolonged breathing of these contaminants can lead to both short- and long-term operator irritations and illness. Respiratory tract irritation, sore throats, eye irritation and headache are the most common symptoms. Allergies and asthma are often exacerbated by solder smoke.

Please note that the metals of which solder is made do not themselves vaporize at soldering temperatures. Lead, the metal with the lowest vaporization temperature commonly found in solders, does not become a gas below 2950ºF.

What you are really getting rid of, and what you want to get rid of, is flux smoke, scorched board material and conformal coating.

Activated carbon filter

Hakko also offers an activated carbon filter, part number 999-182, for applications where odor removal is the prime consideration; this is the primary filter in the HJ3100-04. This filter should be used with a pre-filter (999-136 or 999-201), to keep particles out of the main filter. The carbon filter has an adsorption rating of 80-85%.  It has a much larger surface area than the carbon portion of the standard HEPA/carbon filter, hence a longer life. It should always be used with a pre-filter to preclude being clogged by particulate matter.