Re: PRV and Sampling - With Air Scrubbers On or Off

[Guest guest]

,

Understood. I only do PRV for one particular remediation contractor. I don't trust any others (except my own remediation company). I have them take pictures before they encapsulate. I have them take pictures after they encapsulate. Then they build back the walls and call me for PRV.

In the latest IE Connections there is a good article about encapsulation. They question how much you should care if a bit of growth gets encapsulated.

Smells of paint and bleach are a big deal to many of my clients. I want painting of bleached wood done without any delays. The paint stops the bleach smells. I want the walls put back ASAP as this covers up most of the paint smells and allows sensitive clients to move back in quicker.

Rosen, Ph.D.

www.Green-Buildings.org

Re: PRV and

Sampling - With Air Scrubbers On or OffBob/Ma:Good. We both agree that aggressive air movement is benefit (maybe required?) during PRV sampling. You mention “agitated,” however, when I go into a contained space, let’s say it is 1,500sqft, and there are three to four 2000cfm HEPA air scrubbers operating, the air inside that space is more than just agitated, its down-right turbulent! I often have the remediation contractor operate the air scrubbers a minimum of 12hrs post-remediation, preferably 24hrs, prior to me conducting the PRV inspection and sampling. Moreover, my PRV is done BEFORE any encapsulants are used - I specify the use of encapsulants after PRV inspection and sampling in most, but not all, projects. In my view, if there are reservoirs of biologicals present, those air scrubbers are going to do a much better job of dislodging the material, entraining the material in the air, and keeping it aerosolized during

my sampling effort than I could by simple agitation alone. Yes...they are also scrubbing the air and removing the bio-mass, but it is an iterative process that does not happen quickly. Also, if there are available bio-sources present (that have not been removed) that keep adding to the concentration, 24-hrs is not sufficient time to remove it if it is significant. And if it is not significant, what is the point? If all tests come back favorable, encapsulate the area and restore it back to a pre-loss condition.On 3/8/07 5:27 PM, "Bob/Ma." <Bob@EnvironmentalAi rTechs.com> wrote:

, Don’t get me wrong, I still agitate the air prior to sampling. Simply, I like to see the environment not under filtration (HEPA) prior to sampling. I totally agree with agitation just not with filtration especially hours prior to and leading up to sampling. Bob

Sucker-punch spam with award-winning protection. Try the free Yahoo! Mail Beta.

[Guest guest]

,

If you do pre-remediation sampling with scrubbers on you will never be able to find hidden mold. So no one does it that way. To do PRV with scrubbers on will cover up hidden mold problems and to me makes no sense.

Rosen

www.Mold-Books.com

Re: Mold, Moisture & Remediation Workshop in Cincinnati November ...In a message dated 3/7/2007 12:39:12 PM Eastern Standard Time, garyrosen72652@ yahoo.com writes:

That was the class where they taught to take post-remediation air samples inside the containment with the air scrubbers on.What's wrong with that?Steve Temes

Get your own web address. Have a HUGE year through Yahoo! Small Business.

[Guest guest]

,

Any area in communication with the

contaminated space should be considered part of the contaminated space.

EnviroBob

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

Sent: Saturday, March 10, 2007

10:19 AM

To: iequality

Subject: Re: PRV and

Sampling - With Air Scrubbers On or Off

:

Based on your example......If the attic space is in communication with the

house via recessed ceiling light fixtures or a non-ducted air handler, then

yes, the attic space will influence the air quality of the house.

However, what I believe we were discussing was conducting PRV inspections

and sampling of a contained space where mold remediation occurred, not an

uncontained space. While not all mold remediation efforts take place

under contained conditions, sampling in uncontained areas is a crap shoot.

For what it is worth...

On 3/9/07 1:43 PM, " gary

rosen " <garyrosen72652> wrote:

/Bob,

Here's a common problem ...

You finish your remediation of a particular wall. This gets the spore count in

the house down to a low enough level that you should now be able to see other

secondary problems.

You have recessed lights that are the older type and not sealed. The

afternoon sun heats up the attic and pushing mold spores from the attic into

the house. Or the air handler which is non-ducted, sucks mold spores from

the attic space due to a few openings around the coolant lines leading into the

attic.

You would not see either of these problems if you ran the scrubbers while testing.

You may not care about these additional problems as you were paid to

remediate a particular wall. Or these problems will not make someone sick

as they are minor unless the homeowner is sensitive (cancer, asthma, chemically

sensitive etc.)

However depending on the job and the client PRV that has the scrubbers running

while you are testing may not be appropriate and may be covering up problems.

On the other hand ... in any older house with carpets and old drapes the

background from these components will most likely swamp any effort to try to

find subtle mold growth problems in walls,attics or around air handlers. In

such cases we don't take air samples at all. Our PRV is based on pictures

during and after remediation that all the problem materials have been replaced

with new or brought to like new condition.

Rosen,Ph.D.

Green-Buildings

Re: Mold,

Moisture & Remediation Workshop in Cincinnati

November ...

In a message dated 3/7/2007 12:39:12 PM Eastern Standard Time, garyrosen72652@

yahoo.com writes:

That was the class where they taught to take

post-remediation air samples inside the containment with the air scrubbers on.

What's wrong with that?

Steve Temes

[Guest guest]

,

I hope you are not having me do your

homework for you! My opinions are not made up although they are based on

documents available if you choose to buy them.

Se below;

From: iequality [mailto:iequality ] On Behalf Of gary rosen

Sent: Saturday, March 10, 2007

2:24 PM

To: iequality

Subject: Re: PRV and

Sampling - With Air Scrubbers On or Off

Bob,

Most likely no consultant would be called in [EnviroBob]

and you

know this in advance (problem #1) since when the client sees that

the problem dyrwall is now replaced with new ...and all the structural wood

encapsulated with white paint they will save their money and not do PRV

sampling. [[EnviroBob] and you know this (problem #2) Seeing is

believing.

You should read the article on encapsulation in the latest

IE Connections.[EnviroBob ] have you read the S520? Encapsulation

Encapsulation is not a

cleaning method “and” is

“not recommended as standard practice,” unless items are

irreplaceable, have significant value, or as may otherwise be determined and

agreed upon by materially interested parties in the mold remediation project.

And;

Using encapsulants and sealants is discouraged.

Remediators need to consider that the application of certain encapsulants or

sealant products may change the permeability of materials, cause condensation

problems in the building assembly (trap moisture) an result in future

deterioration and potential liability issues. Use of encapsulants may

impede, mask or invalidate an inspection for dust and debris.

Encapsulants and sealants that have been applied without a complete clean up of

mold growth may result in the necessity of sanding off or removing the

encapsulants or sealant in order to properly remediate the mold growth.

These compounds may contain nitrogen that helps support future mold

growth. Encapsulants may also alter the surface flammability

characteristics of certain materials.

and;

Encapsulation

Encapsulation

is not a cleaning method. Since the Fourth Principle of mold remediation is Removal, it is recommended that encapsulation be avoided as a

standard practice. However, it can be useful in the

following special circumstances:

§

application of a coating over

porous or semi-porous surfaces from which mold cannot be fully removed (e.g.,

shellac, varnish or lacquer over unfinished wood); and

§

lamination of irreplaceable or

valuable documents between two sheets of plastic.

It is recommended that remediators

work closely with IEPs in making decisions about the advisability of

encapsulation

[EnviroBob] finished;

Rosen, Ph.D.

www.Green-Buildings.org

Re: Mold,

Moisture & Remediation Workshop in Cincinnati

November ...

In a message dated 3/7/2007 12:39:12 PM Eastern Standard Time, garyrosen72652@

yahoo.com writes:

That was the class where they taught to take post-remediation air

samples inside the containment with the air scrubbers on.

What's wrong with that?

Steve Temes

Now that's room

service! Choose from over 150,000 hotels

in 45,000 destinations on Yahoo! Travel to find your fit.

Don't be flakey. Get Yahoo!

Mail for Mobile and

always

stay connected to friends.

[Guest guest]

Hlspace,

See below;

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

Sent: Friday, March 09, 2007 9:09

PM

To: iequality

Subject: Re: PRV and

Sampling - With Air Scrubbers On or Off

I see pros and cons to each way: sampling with the

scrubbers/negative

air on and off. The best thing to do is sample with them on (to

prevent the perception of cross-contamination in case there is still

contamination)[EnviroBob]the containment should prevent this if the

containment is still secured

then perform a second test after the first test

results

are back from the lab and indicate a clean environment AND at that

time the srubber (neg-air) is shut off for 24 hours prior to re-

sampling.[bob/Ma.] if the samples come back clean, there is no one who will

resample.

Otherwise you may have other issues e.g.

you wasted their money on unreliable sampling.

Most clients don't want the time and expense of both.

But

that's ultimately the only senrario that allows for preventing cross-

contaminatjon and testing under normal conditions.

[EnviroBob] an air scrubber running IMO are not normal

conditions.

[Guest guest]

,

See below;

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

Sent: Saturday, March 10, 2007

12:35 AM

To: iequality

Subject: Re: Re: PRV

and Sampling - With Air Scrubbers On or Off

:

Read my post to Bob/Ma. You and Bob need to de-couple encapsulation and

moisture....they have NOTHING to do with each other and are mutually

exclusive!

[EnviroBob] disagree; unless you are applying dry encapsulants.

In addition I have noticed that

Applies his encapsulants prior to removing the left behind

moisture as a result of the bleach application.

Even if the encapsulant is permeable it reduces moisture

migration thereby leaning towards more favorable growth conditions.

Moreover, no work site is “free” of dust, dirt or debris.

[EnviroBob] a work site and a remediation site are two distinct

projects. If I were to conduct PRV and I saw

dust, dirt, or debris I would have you call me back when you

have cleaned it up. , I hope you don’t

encapsulate prior to PRV knowing that (as you put it) “Moreover,

no work site is “free” of dust, dirt or debris.”.

On 3/9/07 10:47 AM, " Stacey Champion " <schampioncommspeed (DOT) net>

wrote:

-

If the source of moisture has been addresssed and corrected, the

remediation conducted in a way that would ensure removal, the

project has passed a visual inspection and work site is free of

dust, dirt & debris, and the lab results come back looking

acceptable -

why would you encapsulate on nearly every project?

Just curious.

Stacey Champion

Owner/Consultant

Champion Indoor Environmental Services, LLC

> >>

> >>

> >>

> >>

> >>

> >> Steve,

> >>

> >> Why would one take the air samples when the air scrubbers are

on? I believe

> >> the environment has the potential to be misrepresented if

sampled when the

> >> scrubbers are on. If the environment is clean than having the

scrubbers off

> >> would more closely represent (snap shot in time) the

environments present

> >> condition (prior to removing the containment).

> >>

> >> If one samples the contained environment with the scrubbers on,

than what you

> >> are testing is the efficiency of the scrubbers and not

necessarily if the

> >> reservoir(s) were discovered and removed.

> >>

> >> Keep in mind, if the scrubber’s were set up correctly than

what

you should

> >> have is an AFD that should be filtering at a rate greater than

the emission

> >> rate. What you have proven is the air scrubber(s) is/are

affective

> >> (sufficient for the project intended).

> >>

> >> Also, keep in mind, if the UFD is sufficient enough than

(depending how many

> >> ACH you required) you should get passing results while on (if

you are

> >> subscribing to the magnitude of 10 X’s greater). Consider

if

you sample

> >> within the cleaned/down stream (HEPA filtered) air, again you

can get skewed

> >> results. At a minimum of even 4 ACH that is a lot of filtration

going on. And

> >> if the unit is sized correctly you should get minimal (less

than a magnitude

> >> of 10) results.

> >>

> >> I prefer allowing the environment to rest under neutral

pressure, allowing

> >> greater concentrations to seek low (nature hates an imbalance)

for at least

> >> 24-48 hours (doors and windows closed) and than sample. My

belief is I am

> >> (more likely than not) getting a sample that has a greater

chance of

> >> discovering or confirming absents of a reservoir and/or its

emissions.

> >>

> >> Bob/Ma.

> >>

> >>

> >>

> >> From: iequality

<mailto:iequality%40yahoogroups.com>

[mailto:iequality

<mailto:iequality%40yahoogroups.com>

]

> >> <mailto:iequality

<mailto:iequality%40yahoogroups.com> %5d> On Behalf Of

AirwaysEnv@...

> >> Sent: Wednesday, March 07, 2007 1:31 PM

> >> To: iequality

<mailto:iequality%40yahoogroups.com>

> >> Subject: Re: Mold, Moisture & Remediation

Workshop

in Cincinnati

> >> November ...

> >>

> >>

> >> In a message dated 3/7/2007 12:39:12 PM Eastern Standard Time,

> >> garyrosen72652@... writes:

> >>>

> >>>

> >>> That was the class where they taught to take post-remediation

air samples

> >>> inside the containment with the air scrubbers on.

> >>

> >> What's wrong with that?

> >>

> >> Steve Temes

> >>

> >>

> >

> >

>

[Guest guest]

Testing with scrubbers on may tell you if the remediation of a defined

area (containment) has been completed.

However, it does not tell you that the space is fit for occupancy

because this criteria can be affected by other adjoining areas.

In critical environments, the area should be retested once it is

restored, to document that there are no adjoining complications and it

is fit for occupancy.

This is done in clean rooms and some hospitals.

Bob

[Guest guest]

G.,

"For what its worth" I have found that I agree with you 99% of the time. But here you are intentionally stirring up the air in the indoor environment while simultaneously testing in a heavily filtered environment when air scrubbers are operative.

This is the one percent of the time that I find myself departing from your typically impeccable logic. Its all about occupant exposure potential and source control right? Why would you then mute that potential by having an immaculate air filtering system in operation during your testing while trying to establish/define circumstances under more "typical" living conditions?

Stojanik

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

Testing with scrubbers on may tell you if the remediation of a defined area (containment) has been completed.However, it does not tell you that the space is fit for occupancy because this criteria can be affected by other adjoining areas.In critical environments, the area should be retested once it is restored, to document that there are no adjoining complications and it is fit for occupancy.This is done in clean rooms and some hospitals.Bob

[Guest guest]

Bob:

Testing after all restoration work is complete is a worthwhile thing to do, and I frequently recommend it....assuming there is a budget for it. Unfortunately, there is often no budget for final testing. But I need to ask.....Just what do you mean when you say: “It (testing with scrubbers on) does not tell you that the space is fit for occupancy

because this criteria can be affected by other adjoining areas.” If testing is done within containment, just how are adjoining areas affecting it?

Testing with scrubbers on may tell you if the remediation of a defined

area (containment) has been completed.

However, it does not tell you that the space is fit for occupancy

because this criteria can be affected by other adjoining areas.

In critical environments, the area should be retested once it is

restored, to document that there are no adjoining complications and it

is fit for occupancy.

This is done in clean rooms and some hospitals.

Bob

[Guest guest]

Philip:

Thanks for the compliment.

Yes...There is a lot of merit with respect to sampling under more typical living conditions, e.g., no containment, no aggressive air flows, sheeted walls, carpeting on the floor, windows open, pets under feet, kids running amok, etc. AND I AGREE WITH YOU 100%. This would represent the best measure of occupant exposure. And like I mentioned in my earlier post today, testing post-restoration (after remediation and after re-construction is complete) is probably in the best interests for the occupants re-occupying the remediated space. Testing should be for more than mold spores too – total dusts, fiberglass, VOCs, etc., should all be sampled and tested for. This, in effect, would provide a clean bill of health for the occupants. Great idea....but not practiced.

Standard industry practice (asbestos, LBP, mold, med waste, etc.) has always been to sample and test inside containment, after remediation and before reconstruction. Granted, not the best but it is what we do. So....to make the most of it, I sample after all demolition, removal, and remediation work is complete. Then, prior to encapsulation and prior to the containment being breeched, I have the contractor seal-off the make-up system - therefore the containment is no longer in a negative-pressure condition and there is no make-up air to contaminate the work space. I also have the contractor install fresh air filters on the air scrubbers. After 12 to 14 hours of aggressive air scrubbing inside the sealed containment, I sample. I sample while the scrubbers are operating and I move them around to blow on others areas; and I have the contractor keep all air scrubbers operating until I get results. If the results are favorable, I allow the contractor to do a light mist encapsulation of exposed surfaces, then after it dries they tear-down containment and begin the re-build. It may not be the best method, but it seems to be adequate for me most folks. Is it a heavily filtered environment...yes. However, based on my experience if there are unclean areas that I missed on the visual inspection, they will be well represented in the air sample results.....CMUs with mold are notorious for showing residual contamination; and in these instances, I often allow encapsulation prior to my sampling. Moreover, I find too many faults in the other methods of PRV sampling that I have come across, discussed, and debated, and until I am convinced that there is a better method, this is what I am doing. Thoughts?

G.,

" For what its worth " I have found that I agree with you 99% of the time. But here you are intentionally stirring up the air in the indoor environment while simultaneously testing in a heavily filtered environment when air scrubbers are operative.

This is the one percent of the time that I find myself departing from your typically impeccable logic. Its all about occupant exposure potential and source control right? Why would you then mute that potential by having an immaculate air filtering system in operation during your testing while trying to establish/define circumstances under more " typical " living conditions?

Stojanik

[Guest guest]

Bob,

The remaining area(s) may/can have an

impact upon the contained area (especially if the contained area is under negative

pressure which IMHO is another reason not to have the scrubbers on). I would

like to see the contained area isolated from remaining area(s) and the air not

being scrubbed removing what I am looking to detect (if it’s there).

Allowing the air scrubbers on (minimally

at 4-8 ACH) only skew the samples and camouflages the actual conditions. When

the containment and scrubber are removed any reservoir that was missed may

become amplified at a later point in time, i.e. humid conditions. Will this

become noticeable over night or with a month or so, probably not all though will

amplify from the present condition to a greater condition in less time than had

all the reservoirs been removed.

Let’s take a look at a potential project:

Example:

Say you have a room under containment that

is 20 x 30 x 8 = 4800 CF of air

Most contractors will install a 2000 CFM

(because they only need to buy one unit to do most all jobs, bigger is better,

and their math was not always their best subject). No math needed because S520

says Indoor environmental hygiene practices highly recommend a

minimum of four air changes per hour (four to 12ACH is ideal) for contaminant

ventilation and dilution. This recommendation also is used in mold

remediation.

So contractor may feel buying one large

will work for all (or most scenarios). I do not agree with this presumption (as

many other factors must be taken into consideration). To my surprise, I have

had other consultants and IICRC certified personal ask me how many ACH should

be installed.

For argument sake, let’s say they

install an air scrubber of 2000 CFM

How long will it take to scrub the air

once in a 4800 CFM room?

CFM required = Room

volume (ft3) x Number of ACH

60 minutes

Hint: you only need 320 CFM (320 would be

a small unit (1000 CFM) not a 2000 CFM unit as I see most often). The problem

here is the contractor is not going to cut off any filtration available. He/She

will just use the unit at full capacity (more likely than not).

Most conservative scenario: So using the

1000 (rather than 2000) CFM running in a 4800 CFM room (not a common size room)

how long will it take to scrub the air once? 4.8 minutes!! If they use a 200

CFM (more commonly seen) it will take 2.4 minutes.

All of the air will be run through the scrubbed

in less time than you will take to complete one viable sample (say a 5 minute

sample). It will take 1.6 minutes to scrub (through HEPA) the air once.

Regardless; any percentage of the air that is altered (filtered) no longer

represents the environmental conditions (isn’t this about science).

The percentage of air that was filtered

may have contained the higher emissions or concentrations due to the proximity

of the reservoir and the scrubber.

Again best scenario: If you use a 1000 CFM

scrubber it will take 4.8 minutes to filter 4800 CFM. Which means; even during

your sampling time (if you were ready and turned on the pump the same time you

turned on the scrubber) you would at best be sampling mixed air (filtered and

unfiltered) and the amount of filtered air will be increasing per second.

So what you’re really testing is if

the filtration rate exceeds the rate of emissions and the AFU is suitable for

the size of the room (that is all). The only other information one may gain is

if the HEPA is seated or sealed correctly thus preventing blow-by.

My point is that sampling with AFU on

renders your samples unreliable and unscientific if you are sampling to test

the effectiveness of the remediator contractor with the AFU’s on.

Time is ticking, ticking,

You’d better get sampling, sampling.

Because time is ticking, ticking and all

you will have to sample is filtered air.

Even if there is a reservoir you could

overlook it because the samples will be skewed because you sampled mixed or filtered

air (how much depends on the size of the room as well the size of the AFU). In

addition, the reservoir could be missed due to proximity of the scrubber.

In an area less than 4800 CFM, the air is

cleaned in less time again further skewing your sample results.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Bob s

Sent: Sunday, March 11, 2007 11:13

AM

To: iequality

Subject: Re: Re: PRV

and Sampling - With Air Scrubbers On or Off

Testing with scrubbers on may tell you if the

remediation of a defined

area (containment) has been completed.

However, it does not tell you that the space is fit for occupancy

because this criteria can be affected by other adjoining areas.

In critical environments, the area should be retested once it is

restored, to document that there are no adjoining complications and it

is fit for occupancy.

This is done in clean rooms and some hospitals.

Bob

[Guest guest]

Bob,

Let’s say the area is tested once

restored and fails. Who is going to pay to have it gutted again? I think

someone is going to have some angry clients. I would not like to be the one on

the other end of the table.

If the sampling is conducted with air

scrubber off, you will IMHO (more likely than not) due to depressurization (outside

air migrating in through walls, etc.) be able to sample and achieve more representative

samples. If there is a reservoir in the walls, there is a better chance of any emissions

becoming detectable.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Bob s

Sent: Sunday, March 11, 2007 11:13

AM

To: iequality

Subject: Re: Re: PRV

and Sampling - With Air Scrubbers On or Off

Testing with scrubbers on may tell you if the

remediation of a defined

area (containment) has been completed.

However, it does not tell you that the space is fit for occupancy

because this criteria can be affected by other adjoining areas.

In critical environments, the area should be retested once it is

restored, to document that there are no adjoining complications and it

is fit for occupancy.

This is done in clean rooms and some hospitals.

Bob

[Guest guest]

If there is a reservoir in the walls, there is a better chance of any emissions becoming detectable.

If there is a reservoir in the walls, the time to find it is NOT in your PRV sampling.

Steve Temes

[Guest guest]

Bob,

You are right on the money. This is how it should be for mold. The other method was developed for asbestos. For asbestos you know where the problem is. It does not grow. For mold you don't.

There are many incorrect holdovers that were used for asbestos that people use for mold. But mold is not asbestos. There is a significant background level of mold that is acceptable. The key is to restore the residence to a healthy place (no higher than normal background) for a reasonable price so people can afford your services.

However your explanation of air scrubbing needs a little comment: A 1500 cfm air scrubber does not scrub the air at 1500 cfm. It scrubs the air at the intake at 1500 cfm. You need to have fans going in the room to create a vortex or multiple scrubbers to actually clean the air in a room. Additionally, you must contantly dust the surfaces because dust, dirt and large spores settle out.

You should try a smoke stick the next time you are using a scrubber. You will be surprised at how poorly a scrubber by itself cleans an entire room or containment.

Rosen, Ph.D.

www.Mold-Books.com

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

Testing with scrubbers on may tell you if the remediation of a defined area (containment) has been completed.However, it does not tell you that the space is fit for occupancy because this criteria can be affected by other adjoining areas.In critical environments, the area should be retested once it is restored, to document that there are no adjoining complications and it is fit for occupancy.This is done in clean rooms and some hospitals.Bob

Don't be flakey. Get Yahoo! Mail for Mobile and always stay connected to friends.

[Guest guest]

EnviroBob.

I agree with your example.

I also do not support testing of remediation projects with the

scrubbers on. (Hospitals are a special case with double containment.)

What I wrote:

" Testing with scrubbers on may tell you if the remediation of a defined

area (containment) has been completed. "

may have incorrectly given that impression.

On the other hand,

If you are going to test with scrubbers on ( and some people do this

for various reasons),

then your passing criteria has to be very strict. e.g. 10 times lower

than with the scrubbers off for an extended period of time. Many

people I know

who do, do this, due use very strict criteria.

What I would like to know from the group is?

If you do test with the scrubbers on, What are your acceptance

criteria? <100 spores? < 500 spores? What genera?

Bob

[Guest guest]

Bob,

Thank you for your support.

Secondly:

Your question is a good question although

I am unable to answer b/c I have the AFU off. I am not even able to comprehend

if their strict criterion is reasonable due to the AFU filtering out .3 microns

and above at 99.97%. Maybe the heavier spores will not become as easily filtered

and maybe the others will. So how is one to determine if ten spores are too many

and as you say what genera?

Seemingly one may begin to extrapolate numbers

and this may become unscientific at best. The more one alters or causes an

impact upon results IMHO skews what could have been reliable results if left

unaltered.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of Bob s

Sent: Monday, March 12, 2007 8:50

PM

To: iequality

Subject: Re: Re: PRV

and Sampling - With Air Scrubbers On or Off

EnviroBob.

I agree with your example.

I also do not support testing of remediation projects with the scrubbers on.

(Hospitals are a special case with double containment.)

What I wrote:

" Testing with scrubbers on may tell you if the remediation of a defined

area (containment) has been completed. "

may have incorrectly given that impression.

On the other hand,

If you are going to test with scrubbers on ( and some people do this for

various reasons),

then your passing criteria has to be very strict. e.g. 10 times lower

than with the scrubbers off for an extended period of time. Many people I know

who do, do this, due use very strict criteria.

What I would like to know from the group is?

If you do test with the scrubbers on, What are your acceptance criteria?

<100 spores? < 500 spores? What genera?

Bob

[Guest guest]

EnviroBob,

Yes and no. When we have a non carpeted house with limited fabric furniture and either a clean AC or the AC is off we can get the spore count close to zero (in the entire house or the containment.)

We do this by cleaning room by room. Multiple scrubbers are in each room or a scrubber with 3 fans so that a vortex is created just as they teach in WRT training when you want to dry out a room.

We then use an electric leaf blower to air wash the floors, ceiling, walls etc... and then monitor the total particulate count with a laser particle counter equipment with a 10 micron channel.

We turn off the machines and swiffer the floor and walls and ceiling if smooth ... all surfaces.

Then turn on the machines and air wash and monitor a few times. The particle count will be very low. And the spore count will approach zero.

When the spore count in an air sample is close to zero and there is an absense of settle dust ... sampling is indicative of the cleanliness of the space.

(We only clean like this when someone is very sensitive to mold.) If they have an old dirty AC and ducts and/or old carpet such cleaning is a waste of time.

Rosen, Ph.D.

www.Green-Buildings.org

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

Testing with scrubbers on may tell you if the remediation of a defined area (containment) has been completed.However, it does not tell you that the space is fit for occupancy because this criteria can be affected by other adjoining areas.In critical environments, the area should be retested once it is restored, to document that there are no adjoining complications and it is fit for occupancy.This is done in clean rooms and some hospitals.Bob

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[Guest guest]

,

You would not have followed industry

standards. I would follow industry standards by recommending removing the carpets

and cleaning the duct work and associated equipment as part of the protocol.

Therefore no question would remain.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of gary rosen

Sent: Monday, March 12, 2007 9:38

PM

To: iequality

Subject: Re: Re: PRV

and Sampling - With Air Scrubbers On or Off

<100 spores? < 500 spores?

Is that per cubic meter?

EnviroBob,

This goes back to the earlier question about return to

pre-loss or to pristine? Depends on the particular job. If the

carpet is 40 years old or if the air handler and ducts are filthy then

cleaning a specific area to pristine is a waste of money.

Specific numbers are not useful our field. Which is

good ... and why clients need professionals.

Rosen, Ph.D.

www.Mold-Books.com

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

EnviroBob.

I agree with your example.

I also do not support testing of remediation projects with the

scrubbers on. (Hospitals are a special case with double containment.)

What I wrote:

" Testing with scrubbers on may tell you if the remediation of a defined

area (containment) has been completed. "

may have incorrectly given that impression.

On the other hand,

If you are going to test with scrubbers on ( and some people do this

for various reasons),

then your passing criteria has to be very strict. e.g. 10 times

lower

than with the scrubbers off for an extended period of time. Many

people I know

who do, do this, due use very strict criteria.

What I would like to know from the group is?

If you do test with the scrubbers on, What are your acceptance

criteria? <100 spores? < 500 spores?

What genera?

Bob

<fontfamily><param>Times New

Roman</param><smaller><smaller>EnviroBob.

I agree with your example.

I also do not support testing of remediation projects with the

scrubbers on. (Hospitals are a special case with double containment.)

What I wrote:

" Testing with scrubbers on may tell you if the remediation of a

defined

area (containment) has been completed. "

may have incorrectly given that impression.

On the other hand,

If you are going to test with scrubbers on ( and some people do this

for various reasons),

then your passing criteria has to be very strict. e.g. 10 times

lower

than with the scrubbers off for an extended period of time. Many

people I know

who do, do this, due use very strict criteria.

What I would like to know from the group is?

If you do test with the scrubbers on, What are your acceptance

criteria? <<100 spores? << 500

spores? What genera?

Bob

</smaller></smaller></fontfamily>

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[Guest guest]

Steve et. al.,

I agree with Steve. I'm not going to go on another rant here, but how

many of you out there in PRV land really understand the concept of an

ASSESSMENT/INVESTIGATION, if you're worried about finding

reservoirs in walls after remediation, during PRV??

For those who may not be able to justify the letters after their names,

here's a mini-primer:

1. Visually inspect & interview occupants/owners. Find the moisture

source(s) & correct them. Perform drying.

2. Find/develop hypotheses associated with the usually rather

predictable patterns of growth resulting from elevated moisture for

those microbials that may be " hidden " .

3. If appropriate, test the hypotheses.

4. Develop a Scope of Work.

5. Remediate.

6. Perform further visual inspection(s) DURING the course of

remediation, in order to allow for minor adjustment of the Scope as

may be necessary.

7. Verify the effectiveness of the remediation & attainment of

acceptance criteria (visual inspection & minimal to moderate sampling,

depending on situation).

8. Upon verification that the remediation is acceptable, minimally

encapsulate only if and when (usually very limited & rarely) necessary.

BdthTha...tha...that's all folks! It's really not rocket science.

Here's a helpful hint: If you have no investigative skills, get some or

find a new profession.

Cheers & all that.

Chuck Reaney

In a message dated 3/12/2007 5:10:09 PM Eastern Standard Time,

Bob@... writes:

> If there is a reservoir in the walls, there is a better chance of

> any emissions becoming detectable.

If there is a reservoir in the walls, the time to find it is NOT in

your PRV sampling.

Steve Temes

[Guest guest]

EnviroBob

People cannot always afford removing carpets. And cleaning duct work is typically not useful as the mold is in the fiberglass plenums.

There are no industry standards regarding such issues.

Rosen

www.Mold-Books.com

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

EnviroBob.I agree with your example.I also do not support testing of remediation projects with the scrubbers on. (Hospitals are a special case with double containment. )What I wrote:"Testing with scrubbers on may tell you if the remediation of a defined area (containment) has been completed."may have incorrectly given that impression.On the other hand,If you are going to test with scrubbers on ( and some people do this for various reasons),then your passing criteria has to be very strict. e.g. 10 times lowerthan with the scrubbers off for an extended period of time. Many people I knowwho do, do this, due use very strict criteria.What I would like to know from the group is?If you do test with the scrubbers on, What are your

acceptance criteria? <100 spores? < 500 spores? What genera?Bob

<fontfamily><param>Times New Roman</param><smaller><smaller>EnviroBob.I agree with your example. I also do not support testing of remediation projects with thescrubbers on. (Hospitals are a special case with double containment. )What I wrote:"Testing with scrubbers on may tell you if the remediation of adefined area (containment) has been completed."may have incorrectly given that impression. On the other hand, If you are going to test with scrubbers on ( and some people do thisfor various reasons),then your passing criteria has to be very strict. e.g. 10 times lowerthan with the scrubbers off for an extended period of time. Manypeople I knowwho do, do this, due use

very strict criteria. What I would like to know from the group is?If you do test with the scrubbers on, What are your acceptancecriteria? <<100 spores? << 500 spores? What genera?Bob</smaller></smaller></fontfamily>

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[Guest guest]

Hello Chuck,

Only if the real world were so simple. Many projects are in older buildings where the owner knows no history and there have been numerous water losses that confuse the issues. You describe a simple no brainer scenario.

Bradley Harr MS, CMC, CHMM, RPIHSr. Environmental ScientistSummit Environmental, Inc.bdharr@...

-----Original Message-----From: iequality [mailto:iequality ]On Behalf Of Chuck ReaneySent: Tuesday, March 13, 2007 8:24 AMTo: iequality Subject: Re: Re: PRV and Sampling - With Air Scrubbers On or Off

Steve et. al.,I agree with Steve. I'm not going to go on another rant here, but how many of you out there in PRV land really understand the concept of an ASSESSMENT/INVESTIGATION, if you're worried about finding reservoirs in walls after remediation, during PRV??For those who may not be able to justify the letters after their names, here's a mini-primer:1. Visually inspect & interview occupants/owners. Find the moisture source(s) & correct them. Perform drying.2. Find/develop hypotheses associated with the usually rather predictable patterns of growth resulting from elevated moisture for those microbials that may be "hidden".3. If appropriate, test the hypotheses.4. Develop a Scope of Work.5. Remediate.6. Perform further visual inspection(s) DURING the course of remediation, in order to allow for minor adjustment of the Scope as may be necessary.7. Verify the effectiveness of the remediation & attainment of acceptance criteria (visual inspection & minimal to moderate sampling, depending on situation).8. Upon verification that the remediation is acceptable, minimally encapsulate only if and when (usually very limited & rarely) necessary.BdthTha...tha...that's all folks! It's really not rocket science.Here's a helpful hint: If you have no investigative skills, get some or find a new profession.Cheers & all that.Chuck ReaneyOn 12 Mar 2007 at 19:52, AirwaysEnvcs wrote:In a message dated 3/12/2007 5:10:09 PM Eastern Standard Time, BobEnvironmentalAirTechs writes: > If there is a reservoir in the walls, there is a better chance of> any emissions becoming detectable.If there is a reservoir in the walls, the time to find it is NOT inyour PRV sampling.Steve Temes

[Guest guest]

Brad,

Thank you for your observations & opinions expressed. I couldn't

agree with you more.

As this field includes numerous complexities and considerations (far

too many to fully explore or explain here), the " no brainer " scenario is, I

believe, the type which is most often encountered, and usually include

factors such as roof & plumbing leaks, broken pipes, condensate

system drainage failures, improper grading/surface water drainage,

shallow groundwater, flooding, etc.

As such, most of these will involve health concerns, insurance claims,

etc. and often involve low-rise structures, including residential, which

invariably will bring financial considations into the picture.

As such, the impetus for calling in an expert is again, often, but not

always, a known or suspected event that has occurred within a

reasonably known time-frame.

In these often-encountered scenarios, I stand by my statements in my

previous post, as it is these kinds of " no-brainers " that most concern

me regarding the erroneous assumptions, opinions and resultant

conclusions that are often expressed in this group.

Also, as I'm sure you realize, but others apparently may have

informational processing issues with, not everything is about mold.

Sometimes it's about bacteria, CO, CO2, allergens, heavy metals,

chemical exposures, toxins, herbicides, pesticides, cleaning agents,

construction materials and/or methods, etc., etc., and these

considerations may be linked to HVAC systems, groundwater issues,

previous usage of the land (usually in new construction), air flow &

pressure differential issues, etc.

Additionally, as I'm sure you realize, there are often multiple issues that

may be contributing to health concerns/symptoms expressed by

occupants.

Of course, in older, high-rise, commercial, industrial, urban vs. rural

settings, (again, etc.), other considerations come into play which may

even include (yes, I've encountered this too) what's going on upstream

in the direction of prevailing winds, which also vary seasonally.

These are the reasons that I make my points about investigative skills.

In many of these less encountered scenarios, you had darned well

better HAVE investigative skills, and they'd better be finely tuned and

developed, or something significant WILL be missed or overlooked.

When you're investigating a 100 year old paper mill for example, that a

developer has turned into office or residential units, and there's nobody

around who worked there 100 years ago, not to mention interim usage

of the site, and also not even including usage of neighboring and

nearby sites, how many different possibilities are there for what may be

making people sick? Ok, maybe there was a roof or plumbing leak,

but what ELSE is going on, or went on 10, 30, 60, or 100 years ago?

Overlooking some factors certainly is also possible even with the most

highly educated and experienced among us, but my real concern is

related to those who know NOTHING but mold, and in many cases,

only minimally how to remediate it, and little about investigating it

alone, to say nothing of the scenarios above.

My bottom line here is that there is much ado about everything mold,

and we hardly understand even that limited field, yet there are sooo

many " experts " who are convinced that their way is the only " right " way

to investigate and/or remediate. These people's opinions are being

expressed here and too often even their basic logic is flawed to say

nothing of their " expertise " which is highly limited and too often causes

them to go through life wearing blinders, and espousing their

erroneous opinions to trusting, scared clients. Many of these people

couldn't find their way out of a cardboard box, yet they are expressing

" expert " opinons, based on what?

I believe that we all need to step back from time to time and re-

examine our methods and opinons, from a perspective of " Do no

harm " .

So yes, Brad, I DO agree with you completely. Unfortunately, too many

" experts " in this field aren't even up to speed on the " no brainer "

issues.

Cheers and Regards,

Chuck Reaney

Hello Chuck,

Only if the real world were so simple. Many projects are in older

buildings where the owner knows no history and there have been

numerous water losses that confuse the issues. You describe a

simple

no brainer scenario.

Bradley Harr MS, CMC, CHMM, RPIH

Sr. Environmental Scientist

Summit Environmental, Inc.

bdharr@...

Re: Re: PRV and Sampling - With Air Scrubbers

On or

Off

Steve et. al.,

I agree with Steve. I'm not going to go on another rant here, but

how many of you out there in PRV land really understand the concept

of an ASSESSMENT/INVESTIGATION, if you're worried about finding

reservoirs in walls after remediation, during PRV??

For those who may not be able to justify the letters after their

names, here's a mini-primer:

1. Visually inspect & interview occupants/owners. Find the moisture

source(s) & correct them. Perform drying.

2. Find/develop hypotheses associated with the usually rather

predictable patterns of growth resulting from elevated moisture for

those microbials that may be " hidden " .

3. If appropriate, test the hypotheses.

4. Develop a Scope of Work.

5. Remediate.

6. Perform further visual inspection(s) DURING the course of

remediation, in order to allow for minor adjustment of the Scope as

may be necessary.

7. Verify the effectiveness of the remediation & attainment of

acceptance criteria (visual inspection & minimal to moderate

sampling, depending on situation).

8. Upon verification that the remediation is acceptable, minimally

encapsulate only if and when (usually very limited & rarely)

necessary.

BdthTha...tha...that's all folks! It's really not rocket science.

Here's a helpful hint: If you have no investigative skills, get some

or find a new profession.

Cheers & all that.

Chuck Reaney

In a message dated 3/12/2007 5:10:09 PM Eastern Standard Time,

Bob@... writes:

> If there is a reservoir in the walls, there is a better chance of

> any emissions becoming detectable. If there is a reservoir in the

walls, the time to find it is NOT in your PRV sampling.

Steve Temes

[Guest guest]

Everyone that has done alot of mold remediation knows that this ... Happens All The Time. You are called out to remediate a room at the back of the house. Protocols says remediate room in back of the house. Massive problems there. The PRV test is done and you find mold in the air. Well it did not come from the back of the house since all is new and scrubbed. You go to the front of the house and pull up the carpets and you find another problem. This proble was very small compared to the one in the back and was covered up by the high spore count coming from the back room. If you had your scrubbers on you would never find the problem at the front of the house.

Rosen

www.Mold-Book.com

Re: Re: PRV and Sampling - With Air Scrubbers On or Off

Steve et. al.,I agree with Steve. I'm not going to go on another rant here, but how many of you out there in PRV land really understand the concept of an ASSESSMENT/INVESTIG ATION, if you're worried about finding reservoirs in walls after remediation, during PRV??For those who may not be able to justify the letters after their names, here's a mini-primer:1. Visually inspect & interview occupants/owners. Find the moisture source(s) & correct them. Perform drying.2. Find/develop hypotheses associated with the usually rather predictable patterns of growth resulting from elevated moisture for those microbials that may be "hidden".3. If appropriate, test the hypotheses.4. Develop a Scope of Work.5. Remediate.6. Perform further visual inspection(s) DURING the course of remediation, in order to allow for minor adjustment of the Scope as may be necessary.7. Verify

the effectiveness of the remediation & attainment of acceptance criteria (visual inspection & minimal to moderate sampling, depending on situation).8. Upon verification that the remediation is acceptable, minimally encapsulate only if and when (usually very limited & rarely) necessary.BdthTha...tha. ..that's all folks! It's really not rocket science.Here's a helpful hint: If you have no investigative skills, get some or find a new profession.Cheers & all that.Chuck ReaneyOn 12 Mar 2007 at 19:52, AirwaysEnvcs (DOT) com wrote:In a message dated 3/12/2007 5:10:09 PM Eastern Standard Time, Bob@EnvironmentalAi rTechs.com writes: > If there is a reservoir in the walls, there is a better chance of> any emissions becoming

detectable.If there is a reservoir in the walls, the time to find it is NOT inyour PRV sampling.Steve Temes

8:00? 8:25? 8:40? Find a flick in no time with theYahoo! Search movie showtime shortcut.

[Guest guest]

Everyone that has done alot of mold remediation knows that this ... Happens All The Time. You are called out to remediate a room at the back of the house. Protocols says remediate room in back of the house. Massive problems there. The PRV test is done and you find mold in the air. Well it did not come from the back of the house since all is new and scrubbed. You go to the front of the house and pull up the carpets and you find another problem. This proble was very small compared to the one in the back and was covered up by the high spore count coming from the back room. If you had your scrubbers on you would never find the problem at the front of the house.

Rosen

That's why you test the area outside of the containment in your PRV air sampling. You interpret your work area samples accordingly.

I have passed the contractor's work but "failed the house" a few times. It's not the clearance report anyone is looking for but it is what it is.

Steve Temes

[Guest guest]

I think this is foolish

advice for all of the reasons elucidated by others.  This practice will sooner or later catch up

with you.  Maybe I’ll see you in

court someday.

md

Read my post to Bob/Ma.

You and Bob need to

de-couple encapsulation and moisture....they have NOTHING to do with each

other and are mutually exclusive!

Moreover, no work site is “free” of dust, dirt or debris.

On 3/9/07 10:47

AM, " Stacey Champion "

<schampioncommspeed (DOT) net> wrote:

-

If the source of moisture has been addresssed and corrected, the

remediation conducted in a way that would ensure removal, the

project has passed a visual inspection and work site is free of

dust, dirt & debris, and the lab results come back looking

acceptable -

why would you encapsulate on nearly every project?

Just curious.

Stacey Champion

Owner/Consultant

Champion Indoor Environmental Services, LLC

> >>

> >>

> >>

> >>

> >>

> >> Steve,

> >>

> >> Why would one take the air samples when the air scrubbers are

on? I believe

> >> the environment has the potential to be misrepresented if

sampled when the

> >> scrubbers are on. If the environment is clean than having the

scrubbers off

> >> would more closely represent (snap shot in time) the

environments present

> >> condition (prior to removing the containment).

> >>

> >> If one samples the contained environment with the scrubbers on,

than what you

> >> are testing is the efficiency of the scrubbers and not

necessarily if the

> >> reservoir(s) were discovered and removed.

> >>

> >> Keep in mind, if the scrubber’s were set up correctly than

what

you should

> >> have is an AFD that should be filtering at a rate greater than

the emission

> >> rate. What you have proven is the air scrubber(s) is/are

affective

> >> (sufficient for the project intended).

> >>

> >> Also, keep in mind, if the UFD is sufficient enough than

(depending how many

> >> ACH you required) you should get passing results while on (if

you are

> >> subscribing to the magnitude of 10 X’s greater). Consider if

you sample

> >> within the cleaned/down stream (HEPA filtered) air, again you

can get skewed

> >> results. At a minimum of even 4 ACH that is a lot of filtration

going on. And

> >> if the unit is sized correctly you should get minimal (less

than a magnitude

> >> of 10) results.

> >>

> >> I prefer allowing the environment to rest under neutral

pressure, allowing

> >> greater concentrations to seek low (nature hates an imbalance)

for at least

> >> 24-48 hours (doors and windows closed) and than sample. My

belief is I am

> >> (more likely than not) getting a sample that has a greater

chance of

> >> discovering or confirming absents of a reservoir and/or its

emissions.

> >>

> >> Bob/Ma.

> >>

> >>

> >>

> >> From: iequality <mailto:iequality%40yahoogroups.com>

[mailto:iequality

<mailto:iequality%40yahoogroups.com>

]

> >> <mailto:iequality

<mailto:iequality%40yahoogroups.com> %5d> On Behalf Of

AirwaysEnv@...

> >> Sent: Wednesday, March 07, 2007 1:31 PM

> >> To: iequality <mailto:iequality%40yahoogroups.com>

> >> Subject: Re: Mold, Moisture & Remediation

Workshop

in Cincinnati

> >> November ...

> >>

> >>

> >> In a message dated 3/7/2007 12:39:12 PM Eastern Standard Time,

> >> garyrosen72652@... writes:

> >>>

> >>>

> >>> That was the class where they taught to take post-remediation

air samples

> >>> inside the containment with the air scrubbers on.

> >>

> >> What's wrong with that?

> >>

> >> Steve Temes

> >>

> >>

> >

> >

>