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[This is an archived post from the previous EIA forum.]

Tom L said...

A common issue here...is a contractor that wants to use a "shop vac" that is equipped with a HEPA filter for asbestos work. Major home improvement stores sell HEPA filters for their featured line of shop vacs. I'm sure the thought is for limiting dust emissions into ones home...not to serve as a piece of equipment to provide protection from asbestos exposure. HEPA filters are tested rigorously via a number of standards (ASTM, ANSI, UL, military specs etc.) utilizing a method commonly referred to as "DOP" (dioctyl phthalate) testing. Simply, this testing technique utilizes a fine aerosol of DOP that is generated from specially designed devices. The fitering efficiency is measured on the opposite side of the filter element. HEPA filters are rated in various classes and types. HEPA filters used for asbestos protection are most likely not those that are provided for utilization on shop vacs. Also, it's the filter that is tested, not the devices.

So as mentioned by Bill, we have not been unaware of devices that are poorly desined and allow leakage. This begs to the shop vac issue. I doubt seriously that any homeowner grade shop vac equipped with a "HEPA" filter would pass DOP testing of the device and leakage of asbestos would be likely. Therefore use in an in an uncontained environment would be undesireable in regards to asbestos exposure protection.

A number of our regular students perform rigorous testing of their HEPA filtered devices and report that, save a few brands, of HEPA vacs and negative air machines (the devices, not just the filter) routinely leak and fail DOP testing...it's unlikely a shop vac/HEPA rig would pass

[This is an archived post from the previous EIA forum.]

JPBrake said...

First let me sincerely thank Bill, Tom and others who have responded to my question on HEPA Filters. There were also some private individual messages sent to me through this forum from persons who preferred anonymity.

Here is what I've decided is appropriate for myself and my work. It is not intended to be a recommendation for anyone else under any circumstances. Its just what I've decided to do based on all I've learned.

I perform lead-abatement. This topic was posted under the Asbestos forum because I thought I'd get more responses.

When I'm working INSIDE a dwelling vacuuming lead dust I will use a HEPA Vacuum System designed for collecting hazardous materials such as Asbestos, Lead, ect.

When I'm working OUTSIDE a house - and windows/doors are closed and the occupants are not present I will use a commercial, contractor grade "shop vac" with a HEPA filter designed for that particular vac model. The HEPA filter will have the same efficiency rating of the HEPA System used inside the dwelling (99.97% to .3 um).

The outside work will consist of vacuuming bare dirt for paint chips.

I'm not going to use a $300-$500 vacuum on bare dirt. I will use a shop vac with a HEPA filter outside a house on bare dirt.

I think this is reasonable under the circumstances presented and discussed.

Please, if anyone believes I'm doing wrong correct me.

Thanks again for the participation.

I'll see you in Charlotte in March, 2007. Yes, that was a blatant plug for the EIA Annual  Conference.

Perry Brake