RE: Leaf Blowers in Mold Remediation

[Guest guest]

Josh,

My studies of using a leaf blower in mold

remediation, is after the remediation has been completed; and it can be used as

a final clearance procedure for the removal of micro-fine surface dust and

spores.

When I say study, this is what I generally

find:

1. The remediated area appears “visually” to be clean

after HEPA vacuuming, however, the containment “failed” (a term

used by some IEPs that I do not approve of) “to achieve clearance”

(another term I do not approve of);

2. Negative air is running to where the supply air is coming from the

clean air of the building or outside air;

3. Airborne particle counts are low, but the airborne mold sample data

showed fungal anomalies (Stachybotrys spores and cell particles) that continue

to be unusually high;

4. After re-inspection of the area to ensure there are no hidden water

damaged areas remaining and the building materials are dry, re-HEPA vacuum the

area. Then consider setting up a “separate” capture filtration

system inside the containment:

a. As simple as one or multiple 18 inch x 18 inch or 20 inch x 20 inch

box fans with 2 inch pleated filter attached (with duct tape) exhausting outside

or to an air scrubber inlet (all factors depend on the size of the containment,

building materials, equipment, filtration and exhaust);

b. A second set of one or multiple box fans are placed at the other

side of the containment that supply a forced-airflow stream directly to the

capture area. (Note: the capture area should have more exhaust air pressure than

the supply air pressure being delivered to it, otherwise you get backpressure.)

c. The leaf blower (electric not gas) is turned on at the “farthest

side of the containment,” thus, blowing “across” ceilings,

walls and floor toward the air stream leading to the capture filtration.

i.

Particle

counts tend to jump from background (e.g., 200 to 1,000 particles) to above

background (200,000 +).

ii.

In

several instances, micro-fine dust became so much of an issue that the increase

of eye and respiratory protection had to be increased.

d. Surface and air scrubbing took an average of 15 to 30 minutes (per

room).

e. On completion, airborne particle counts reduced dramatically to

more than 80% of the high particle count values.

f. Box fans, air scrubbers and filters were bagged and removed from

the containment.

g. Surfaces such as plastic containment and the existing negative air equipment

were HEPA vacuumed and damp-cloth wiped down.

5. Factoring in a particle’s settling rate, the IEP tested the

containment’s air and surfaces 24-hours later. The laboratory results

were favorable to where the contained areas passed the IEPs test objectives.

Moffett

From: iequality [mailto:iequality ] On Behalf Of Josh

Sent: Tuesday, November 21, 2006

7:45 AM

To: iequality

Subject: RE: Clearance

testing & " standards "

This was a response I received from someone else and my reply was

1) where does the leaf blower come from (where has it been stored, was it used

on another job, etc.) and 2) should it be considered

“sterile” enough to bring inside of containment? It would

seem to me if we are talking about 1,2,3….spores, I need to really

consider everything that is being brought into containment.

Josh

From: iequality

[mailto:iequality ]

On Behalf Of Wei Tang

Sent: Monday, November 20, 2006

8:28 PM

To: iequality

Subject: Re: Clearance

testing & " standards "

IMHO, one or two

Stachy spores in the air is no big deal if the surface is all cleaned up.

However, it would be a problem if the surface is not sufficiently cleaned. Ok,

now, how do we test for surface? One (or a few) square inch of sample is

not going to tell you much on the entire job, right? Have the consultant use a

electric leave blower (a small one, please) and blow all the spores off the

surface while sampling to see if he can get any significant amount of Stachy

(or any other) spores in the air. Of course, you should blow the

spores/hyphae off the dried surface while running the air scrubber for

some time before the PRV. Please see Bob s' PRV book for details.

Wei Tang

QLab

healthyiaq

<josh2cureit> wrote:

Our company

performs both investigations and remediation. We only do

both if it is a smaller residential project but on commercial projects

we call in a third party inspection company (We are located in a rural

area). I have used a different company for the first time on a

commercial remediation project and they wanted to fail me for 2 (two)

stachybotrys spores that showed up in an air sample post remediation.

They found the area cleaned and remediated properly. Investigation

showed no other signs of contamination in other areas. Our remediation

supervisor runs a tight ship. Am I to think that this should not

pass? Especially given that there was ONE air sample taken?

I want to take a quick minute to say that for the last year or two I

have been one of those " silent lurkers " . I do appreciate the

different posts and I do think (most of the time) that this is a great

site.

Josh

Wei Tang,

Ph.D.

Lab Director

QLab

5 Drive

Cherry Hill,

NJ 08003

www.QLabUSA.com