»Ø¸´£º Re: Re: Clearance testing & standards

[Guest guest]

Dear Don,

How do you do!

your clearance opinions are very impressive, and I am

trying to do the mold remediation in china. Can you

provide more futhur experience about mold remediation?

Maybe you are not familiar with the policy in china,

china has not special certification for mold

remediation, and no special requirements for the mold

remediation projects, usually this kind of remediation

is entrusted to a cleanrance company(not special,

everyone without training can do).

be frankly, I have not done such mold remediation

experience yet, while I am always following up the

information from EPA, and other useful informations

from internat such from you. and I want to follow up

your project style.

Here is my new company address:

http://www.tech-ehs.com/eindex.aspx;

and my backgroud is Master of public health, certified

doctor of public health, certified safety engineer.

and we have other specialists in different fields.

therefore, I belive that we can undertake such

remediations Could you provide some ideas about this

kind of remedation?

Regards,

Mark Zhang

--- Schaezler дµÀ:

> :

>

> Thanks for your response. All you saw was a small

> excerpt of my

> clearance document. It is part prescriptive and part

> subjective. The

> prescriptive part is based on my experience

> performing hundreds of

> clearances over a number of years. The subjective

> part relies on the

> experience and professionalism of the consultant

> doing the clearance,

> and on the consultant's evaluation of the

> site-specific characteristics.

>

> Trace is purposely not defined to afford the

> consultant flexibility. Of

> course, it must be reasonable and justifiable, and

> the clearance report

> should address those issues. In my experience, there

> may be one spore of

> anything, including Stachybotrys, in a 75 liter

> sample of air from just

> about anywhere. The detection limit is one spore, if

> a complete trace of

> the slide is read, and one spore provides a

> convenient lower limit on

> the concept of trace.

>

> Also in my experience, the occurrence of one spore

> of Stachybotrys in a

> well-cleaned remediation area is rare, in the

> absence of some source.

> The source may well be a hidden cavity that has not

> been remediated, a

> space, such as an attic or crawl space, that has not

> been properly

> isolated from the remediation area, contamination of

> the HEPA-filtered

> air scrubber, outdoor air if negative pressurization

> is in effect, or an

> area that has not been properly cleaned. As we all

> know, Stachybotrys

> spores are difficult to suspend in air and difficult

> to keep suspended,

> and their presence inside a remediation area must be

> addressed.

>

> Evaluation of Aspergillus/Penicillium spores is more

> complicated and

> depends on the air circulation and cleaning

> circumstances. I prefer to

> have negative pressurization in place with defined

> supply locations for

> outdoor air. That makes the logic of indoor to

> outdoor comparisons very

> clear. It is important to have other potential

> sources of air such as

> attics and crawl spaces sealed.

>

> Comparisons of As/Pn levels between specific

> locations within the same

> remediation area can be very useful. I have found

> elevated levels of

> As/Pn spores numerous times in specific remediation

> areas, and not in

> others, and they have often been indicative of

> hidden or incomplete

> contamination. They are also often the result of

> leakage of air from

> attics and crawl spaces into the remediation area.

>

> The issue, usually, is not whether 2 spores or 2,000

> spores are

> hazardous. The issue is actual cleanliness compared

> to achievable

> cleanliness. In my experience, my criteria for

> inspection, relative

> humidity and dew point testing, moisture content,

> surface sampling, and

> air sampling work. When the work is done well, the

> areas pass. When the

> work is not done as well, the areas often fail but

> pass after additional

> cleaning. When the work had been done well, but

> specific locations have

> excess airborne spores, hidden contamination often

> must be found and

> remediated. Often air circulation and cleaning have

> to be changed to fit

> the circumstances. Negative air pressurization is

> problematic when the

> outside air is very humid. Even air scrubbing with

> recycling of the

> discharge can cause local negative pressurization

> and leakage of air

> into the remediation area from inconvenient areas.

>

> Errors in analyses are potentially very important. I

> once had a project

> where samples from similar areas of a building were

> sent to two

> different labs. One found Stachybotrys in every

> sample and one found no

> Stachybotrys. I had another projedt where one set of

> wall cavity samples

> had Stachybotrys in every sample and a followup set

> found one spore of

> Stachybotrys in only one of several samples. It is

> also the

> responsibility of the consultant to recognize

> potential lab errors and

> to address them.

>

> Distribution variability is certainly an issue, and

> here the experience

> and judgment of the consultant comes into play.

> Usually two or more

> samples of outdoor air have similar numbers and

> distribution. Note the

> use of the term similar. Sometimes they do not and

> one has to justify

> which outdoor samples to use for comparison to which

> indoor samples.

> Distribution variability can be very great in very

> clean indoor

> environments where there may only be a few spores of

> each type.

>

> If we were dealing with a specific pathogenic

> Aspergillus species, then

> we should use very stringent criteria and speciation

> of airborne fungi.

> Lacking such specific issues, I have found that

> microscopic

> identification of spores, with all of its

> limitations, has been

> sufficient to evaluate clearance of fungal

> remediation in a practicable way.

>

> These answers represent some of my thought processes

> behind my clearance

> documents. I expect that none of this group will

> agree with all of my

> answers or positions, I am sure the documents can be

> improved upon with

> input from others. My bottom line position is that

> my document works and

> is reasonably fair to all parties involved. When I

> do clearance, it is

> not unusual for clearance to fail on the first

> attempt. Usually, there

> is a good reason, and subsequent attempts pass. If

> there is a better way

> to do clearance, I am certainly willing to learn and

> adapt.

>

> Don Schaezler, Ph.D., P.E., CIH

> ETC Information Services, LLC

> 19349 Old Wiederstein Road

> Cibolo, Texas 78108

>

> fax

> mobile

> donald@...

>

> healthyhouse@... wrote:

> >

> > Well Don, you struck a chord with me. Can you

> please provide some

> > justification for your decision-making criteria.

> Please be patient,

> > these are honest questions that I believe need

> answers from the

> > industry, not just you. Thanx.

> > Why? isn't this 'trace' level? why one not two?

> was 'trace' levels

> > defined prior to the remediaiton so all parties

> knew what was/wasn't

> > passing? would you pass 500

> aspergillus/penicillium group if it was

> > less than outdoors? how do we know it's not

> different than the outdoor

> > sample with 1000 asp/pen group?

> > What could be the reason for such stringent

> criteria? is 2 spores

> > really a hazard? is it worse than 2 spores

> cladosporium? if so, why?

> > where's the reference and support for such

> decision-making? what about

> > error in analysis? what about distribution

> variability? how do we know

> > those 2 were really stachy? why not 2 spores of

> some aspergillus

> > species? or other pathogenic species?

> > These are questions that MUST be answered in order

> to create and use

> > proper PRV protocols.

> >

> > Armour, M.S.

> > Armour Applied Science, LLC

>

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