Hepa Shop Vacuum : What to Look For
A HEPA shop vacuum is designed to filter particles of 0.3 microns with 99.97% efficiency. Hepa stands for high efficiency particulate air and applies to the filter used, not to the device it's used in.
A true hepa shop vac does not allow leakage of air past the filter. This is very important when dealing with hazardous materials such as lead and asbestos. Dust from some species of wood is also considered dangerous, possibly containing carcinogens and potentially causing respiratory disease or sensitisation.
Shop vac hepa filters are available for most makes of vacuum, notably from Cleanstream.com
if not from the shop vac manufacturer themselves.
The use of these hepa filters in a shop vac designed for general applications can be beneficial, but air containing dangerous particles could leak past the hepa filter, contaminating the air in the area you are attempting to clear.
Hepa filters are tested using a device which generates a quantity of DOP (dioctyl phthalate) on one side of the filter, and detected on the other side of the filter. Only the filters are tested, and the EPA (environmental protection agency) does not test filters in conjunction with shop vacs. The EPA does have standards for hepa shop vacs which manufacturers use as guidelines in design and production.
Below is a list of links I put together of manufacturers who produce real hepa shop vacs.
Dustless Tehnologies hepa vacuum Nilfisk hepa vacuum Pullman Holt hepa vacuum American vacuum company hepa vacuum Goodway hepa vacuum Nikro hepa vacuums
Pulse-Bac hepa vacuum