Annual Review of CDW 2012 - Molecular Cleanz Annual Review of CDW 2012 Author Gary Rosen, PhD Subject Chinese Drywall Created Date 1/2/2013 10:47:06 AM

December 30, 2012

Annual Chinese Drywall Technology Review 2012

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Copyright (c) 2012 Gary Rosen, Ph.D. www.Chinese-Drywall.org www.Molecular-Cleanz.com Page 2

Annual Chinese Drywall Technology Review 2012

Advances in Chinese Drywall Assessment Technology

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Inside This Report

• Inside this report we review pertinent background information from earlier US government Chinese Drywall (CDW) studies.

• We review the theory of CDW Off-Gassing called the Dual Component Theory of CDW Off-Gassing and present experimental data that supports the theory.

• We present test results (from Chinese-Drywall.org) that compare Chinese drywall Direct Corrosion Testing to Air Sampling for CDW gases.

Copyright (c) 2012 Gary Rosen, Ph.D. www.Chinese-Drywall.org www.Molecular-Cleanz.com

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Results of Direct Corrosion Testing vs

Air Sampling

• Results show that air sampling for CDW gases is not reliable compared to directly measuring CDW corrosivity using a technique called SDT (Sulfur Deposition Testing.)

• Results explain why the leading Chinese drywall assessment companies focus on measuring CDW corrosivity directly (SDT) and do NOT focus on air sampling for post-remediation clearance testing.


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Focus of 2012 Annual Review

After all it is Corrosive Chinese Drywall that

we are interested in.

So why not focus on directly measuring drywall corrosivity rather than focus on measuring possible indicators of CDW

corrosivity such as attempting to measure levels of CDW produced gases, or S8 levels within the drywall, that may or may not be

reliable measures of CDW corrosivity?



Background and Early History of Chinese Drywall

Studies LBNL S8 Studies

Page 7

S8 Not Found in All Corrosive Drywall

• On page 72 of my theory of Chinese Drywall Off-Gassing Causation, dated 6-1-11 (as published on www.Chinese-Drywall.org) I review the work of Lawrence Berkeley National Labs (LBNL) on the affect of Elemental Sulfur (S8) contaminants on CDW corrosive gas emissions.

• LBNL shows that some of the most corrosive drywall does not contain S8.

• Certainly if some of the most corrosive CDW does not contain S8, S8 is either not the cause of, or at least not the sole cause of Chinese drywall corrosivity.


http://www.chinese-drywall.org/files/unified-theory-of-cdw-off-gassing-causation-6-1-11.pdf










http://www.chinese-drywall.org/



Page 8

Sulfur Bacteria Major Cause of Drywall

Corrosion and Odor

• We know that Elemental Sulfur (S8), when present does appear to contribute to off-gassing/ corrosion.

• However we now know that the major cause of CDW off-gassing in most corrosive Chinese drywall is from sulfur bacteria*.

• Such bacteria are especially active in warmer humid months when corrosion and odor from problem CDW are highest.

*Reference: filebox.vt.edu/users/chagedor/ biol_4684/Cycles/Soxidat.html)


Page 9

Selective Study of S8 Off-Gassing

• One can selectively study Elemental Sulur (S8) off-gassing during cooler / drier winter months when the bacterial component of CDW is much less active.

• S8 contribution to off-gassing is strongly corrosive to Silver (Ag) but only moderately corrosion to Copper (Cu). And the color of corrosion from Elemental Sulfur is not the black sooty corrosion produced by the Hydrogen Sulfide (H2S) released by bacteria but is lighter in color.

• Whereas the bacteria contribution to corrosion which is H2S (and SO2 and CS2) is strongly corrosive to both Ag and Cu and produces a black sooty corrosion. See next page from (www.drywallsymposium.com/ SpeakerPresentations/Tuday.pdf.)



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Different Corrosive Gases Result in Different

Corrosion Patterns/Colors


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Assessing Corrosive Drywall by Measuring S8

No doubt much or most problem CDW has elevated Elemental Sulfur (S8) content.

(www.drywallsymposium.com/SpeakerPresentations/Tuday.pdf.)

Nevertheless, if S8 is NOT typically the major cause of Chinese drywall corrosivity (corrosive

gas release) then measuring S8 content of Chinese drywall as a reliable method for assessing corrosive Chinese drywall has

limited value.


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Conclusions Regarding S8

Elemental Sulfur (S8) is not typically the major cause of CDW corrosion in problem CDW homes. But

contributes to corrosion when present.

The major cause is bacterial which releases three corrosive gases including Hydrogen Sulfide (H2S), Sulfur Dioxide (SO2) and Carbon Disulfide (CS2).



When S8 levels are only slightly above 10mg/kg the drywall will be slightly corrosive but may not be

considered problematic.

At very low S8 without any bacterial growth, homes will not have odor, irritation or heavy corrosion that are

indicators of problem drywall/ homes.


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When S8 levels are very high (i.e. significantly above 10mg/kg), the drywall will be somewhat

corrosive.

But again, if there is no concomitant bacterial growth there will be no smell or irritation (from

gases released by bacteria) nor without bacterial growth will there be any typical CDW corrosion of heavy black tarnish (black soot) on exposed copper due to Hydrogen Sulfide (H2S) release.

Picture of different colored corrosion reproduced again on next page.


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Different Corrosive Gases Result in Different

Corrosion Patterns/Colors


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Dual Nature of CDW Off-Gassing

Almost all Chinese drywall produces corrosive gases from both Elemental Sulfur (S8) and sulfur bacteria.

That is the

Dual Nature of CDW Off-gassing.


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Post Remediation Testing

Must Test ALL Gases

Any system for measuring CDW off-gassing must be able to measure contributions from both sources: Both Elemental Sulfur (S8) and bacteria releasing

H2S, CS2, COS and SO2.

Any system for remediating Chinese drywall in place (without removal) must be able to eliminate corrosive gases from both S8 and bacteria.


Page 18

Post Remediation Testing

Must Test ALL Gases

CDW releases a number of corrosive gases.

As we shall see, attempting to measure the ultra low levels of corrosive and odorous gases found in

homes by selectively air sampling for these gases is both costly and unreliable.

Post remediation corrosion testing using a method called Sulfur Deposition Testing (SDT) can

accurately show that ALL corrosive gases are gone.

Sulfur Deposition (Corrosion) Testing does not care which gas or how many gases are there … only that

they are gone.


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SDT Corrosion Testing

is Highly Accurate

By directly measuring the corrosivity or lack of corrosivity of the indoor air using Sulfur Deposition (Corrosion) Testing one may determine if a home is problematic or is problem free both reliably and cost

effectively even at:

• Gas levels well below the detection limit of any known air sampling techniques.

• And at gas levels far below odor threshold limits.


H2S and SO2

Studies


Page 21

SO2 and Not H2S the Major Gas

Produced by CDW

• In LBNL Phase I studies (page 26) they report that Hydrogen Sulfide (H2S) in the presence of oxygen (as in all homes) broke down to Sulfur Dioxide (SO2) quickly “even in the short period required to measure emissions”.


Page 22

SO2 and Not H2S the Major Gas

Produced by CDW

• While H2S in the presence of oxygen broke down to SO2, Hydrogen Sulfide (H2S) did not break down (or did not break down as quickly) when tested under N2 (under Nitrogen in a lab environment with no or limited Oxygen present).

• So LBNL repeated their off-gassing experiments in Phase II under N2 to further study H2S off-gassing.


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CDW Produces High Levels of SO2

• Under Nitrogen, H2S release is very high; but even under Nitrogen when H2S is relatively stable, the level of SO2 (Sulfur Dioxide) released by Chinese drywall is still high, and except for H2S, SO2 is released in far greater amounts than the other CDW gases: COS, CS2, Methyl Mercaptan or Dimethyl Sulfide (see table below).


Page 24

Lakeland Labs, Centek, CAS Do Not Measure

SO2 in Air Samples

• When an air sample is sent to any of these labs for Chinese drywall gas analysis (method ASTM D-5504) only H2S, CS2, COS, Dimethyl Sulfide and Methyl Mercaptan are measured.

• The most prevalent gas, Sulfur Dioxide (SO2) − both corrosive and irritating − produced by corrosive Chinese drywall in a home (Oxygen filled and not Nitrogen filled of course) is NOT measured by Lakeland Labs, CAS or Centek in Air Sample analysis.


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Lakeland Labs, Centek, CAS Do Not Measure

SO2 in Air Samples

• It is never mentioned in their reports that the corrosive and irritating Sulfur Dioxide (SO2) gas is not part of their analysis and finding no Chinese drywall gases in homes does not in any way mean that there are no Chinese drywall gases present.

• Remember that according to LBNL, SO2 should be the most prevalent gas found in CDW homes because while H2S is the gas most released by corrosive CDW, H2S quickly breaks down to SO2 when oxygen is present (and of course, oxygen is always present in homes.)


Page 26

Focus On H2S is SUSPECT

• Environmental Assessment firms working for builders focus on measuring H2S as an indicator of whether a home is “safe” or not.

• But the CPSC concluded that corrosion is 10x to 100x higher than can be attributed to measured indoor air levels of H2S so there must be high levels of corrosive gases involved besides H2S.


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Focus On H2S is SUSPECT

• That there are other corrosive gases present in homes besides H2S, and at significant levels, makes complete sense as H2S produced by CDW is not stable in homes and quickly breaks down to Sulfur Dioxide which is also corrosive (and irritating.)

• Focusing on H2S and not finding much and then pronouncing homes “safe” (i.e. properly remediated) is SUSPECT.


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True Measuring SO2 Adds Another Layer of

Complexity

• It is true that measuring the corrosive gas SO2 in addition to H2S adds to complexity and cost.

• However when one directly measures copper corrosion using SDT, one measures the contribution of ALL corrosive gases to copper corrosion including H2S, CS2, COS, and SO2 - which are the four corrosive gases produced by Chinese drywall.

• Such corrosion measurements are simple and relatively low cost.


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Conclusions on Measuring S8 and H2S, COS,

SO2 and CS2 Levels

Only by directly measuring the corrosive affects of CDW released gases (Sulfur Deposition Testing) on Cu test coupons can one definitively confirm

that a home has been properly remediated because corrosion testing is the only method that detects the presence of low levels (even

ultra low levels) of all corrosive Chinese Drywall gases including SO2, H2S, CS2 and COS.

Air sampling does not detect all corrosive gases and is not reliable when measuring low levels, much

less ultra low levels in the 1-2 ppb range, of such gases. It does not detect SO2.


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Conclusions on Measuring S8 and H2S, COS,

CS2 and SO2 Levels

And SDT is selective.

Common non-CDW corrosive agents such as salt air, ammonia, bleach, and moisture DO NOT

interfere with SDT as they do with other methods of direct corrosion measurement

such as CheckMate.

SDT is reliable. No false positives.


One Recent Comparison Between Off-Gassing Testing

and Corrosion Testing:

False Positive


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Post Remediation Testing on Homes Remediated with Molecular Cleanz™

• Our policy with Molecular Cleanz™ (www.Molecular-Cleanz.com) is if the process does not work to eliminate corrosive gas release (and odor) in the home you do not pay.

• By far most people are completely convinced when all the odor and irritation are gone.

• But others want their home tested after our remediation efforts are completed.


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Post Remediation Testing on Homes Remediated with Molecular Cleanz™

• We’ve been recommending both: 1) SDT based corrosion testing and 2) air sampling for post remediation testing until recently when we were shocked to find several situations where air sampling was far off the mark.

• So not only does air sampling not measure the important Chinese drywall gas SO2, but it is not reliable in measuring the gases that it does test for.

• In the next few slides I share some of this data that shows that air sampling is not always reliable.


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The Home In Question

• A client’s home that was remediated with Molecular Cleanz™ was known to contain mildly corrosive C&K brand of CDW.

• In fact the exposed copper tubing associated with the interior air conditioning (AC) unit was not black even after being exposed to ambient CDW air for six years with no AC running. Or maybe someone had cleaned it?

• There was some blackening to electrical wiring and there was odor.

Copper Coolant Line

in Unit 703


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High Levels of H2S in Remediated Home???

• For Molecular Cleanz™ this should be a piece of cake … remediating a home with only mildly corrosive drywall.

• So it came as a big surprise when the third party assessment company hired by the owner found elevated levels of Yhdrogen Sulfide (H2S) in the indoor air after the Molecular Cleanz™ remediation. See below.


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Elevated H2S

• GLE/Centek found high levels (4.6 ppb) of H2S in a home (after Molecular Cleanz™ remediation) that had no odor and the home had only moderately corrosive CDW.

• In all the testing we have ever read about or performed we have not seen this high level of H2S measured even in the most highly corrosive homes. Consequently, we suspected a False Positive.


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Big Problem With False Positive

• However the lab insisted to their client (GLE) that this elevation was real and not a contaminant or anomaly in the analysis (otherwise they would have to refund the lab fees).

• Of course we wanted to get paid for our Molecular Cleanz™ treatment so we hired an independent consultant (hygienist) to redo the air sampling but also perform corrosion testing using SDT methodology.


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Third Party Hygienist Results

• The hygienist we hired (Joe Petrauskas) found no detectable copper coupon corrosion after remediation whereas under identical conditions he had measured significant corrosion before the remediation. Top panel.


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Third Party Hygienist Results

• The hygienist (Joe Petrauskas) took air samples inside and outside and sent them to Lakeland Labs.

• The results contradict the Centek results and show no elevation of Hydrogen Sulfide (H2S) or other tested corrosive gases. Bottom panel below.


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And Yet Another Round of Testing

• These results allowed us to challenge the GLE/Centek findings.

• The client then hired Chinese Drywall Screening, LLC to perform yet another round of corrosion and air sampling studies that also found no detectable corrosion and no trace of H2S after Molecular Cleanz™ treatment.

Air Sampling by CDS in Unit 703


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And Yet Another Round of Testing

• So the GLE/Centek results were discredited as a False Positive and we were paid … Whew!

Setting up Corrosion Testing by CDS. Red Boxes are Sealed

Accelerated Corrosion Test Devices


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Clearly from this data, air sampling can result in False Positives.

Was there residual H2S in the stainless steel air collection cylinder (cylinder not clean) that

caused the false positive?

Was there something wrong with the analysis?

Unknown.

But we do know that such false positives do not happen with SDT based direct corrosion

testing.

Air Sampling Can Result in False Positives


Comparison Between Gas Sampling and Corrosion Testing:

False Negative


Page 44

Just Last Month

• Just last month we got a job to remove and replace drywall (not treat with Molecular Cleanz™) in a townhome in Coconut Grove, FL.

• This was one of the smelliest and most irritating homes we have been in (corrosive and smelly Chinese drywall on all the walls as well as the ceilings.)

• We decided to do a pre-remediation corrosion test and a pre-remediation air sample and expected both to be off the charts.


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Corrosion Off the Chart

• So, we made a simple accelerated corrosion detection device consisting of a 60 cfm bathroom exhaust fan with a copper coupon mounted 6” from the air discharge outlet.

• Black arrow points to copper coupon in front of air flow.


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CDW Corrosion Off the Chart

• On the right is the copper coupon exposed to high speed CDW air in this townhome for only 8 hours (under accelerated conditions).

• On the left is a control.

• Coupons were sent to Drywall Science, LLC for XRF analysis of sulfur deposition. Results for test coupon were 26 ug/cm2

• That’s off the charts for only 8 hours!


Page 47

Air Sampling ZERO

• Air sampling results (from Lakeland Labs) found zero detectable CDW gases (see below)! And this from a home that has the highest levels of copper corrosion we have ever measured!


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Was There Nothing There or Was There a Problem with the Analysis?

• Matrix spike control found the recovery of the H2S 25 ppb spike to be 79%. 21%, or over 5 ppb of the sample, was lost during analysis.


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Or Was There a Problem with the Testing?

• But the matrix spike duplicate performed at the same time had 129% H2S recovery (see black arrow).

• Recovery of H2S ranged from 19.8 to 32.3 in the same experiment! (See yellow arrow).

• J2 qualifier (in black rectangle) means something is haywire with the analysis.


Page 50

Or Was There a Problem with the Testing?

• So, was there actually no H2S (or other CDW gases measured by this method) in the stinky and corrosive home but the corrosion was from something other than H2S (such as SO2 that is not measured by such air sampling)?

• Or was there a problem with the lab analysis?

• In either case the result of the air sampling is not in any way, shape or form …. a reliable indicator of CDW corrosivity.


Page 51

Using SDT, the copper coupon corrosion with an 8-24 hour exposure under fan always

correlates well with observed electrical and AC exposed copper corrosion as well as

detected odor.

The cost to have a coupon analyzed by XRF for sulfur deposition by Drywall Science is $25

(min of 4) with a typical one-day turn around.

For this price, one takes duplicates as well as outdoor controls for all jobs.

Copper Coupon Measures Corrosivity of CDW


Page 52

Air sampling now costs $250 per sample with a 4-5 day turnaround - add to that overnight

FedEx charges (OUCH!)

Hard to do duplicates and outdoor controls for this price.

And due to false positives and false negatives and reliability issues with the lab analysis, one can never tell what the results mean when one takes a simple snap shot of the

ambient air by air sampling.

Air Sampling: False Positives and False Negatives. Not Reliable


Page 53

Best to directly measure CDW corrosivity by measuring copper coupon corrosion using

SDT that selectively measures ONLY corrosion contributions from corrosive CDW gases and not from common house hold contaminants.

Air sampling. Not reliable

Measuring S8 content of drywall. Not reliable.

Non-selective corrosion measuring systems such as CheckMate. Not reliable.

SDT = Reliable


Page 54

CDW produces corrosive gases from the two CDW processes: S8 and Bacteria.

Direct corrosion measurements by SDT include contributions from all released corrosive CDW

gases including SO2 which is not assessed with air sampling.

Direct corrosion measurements by SDT measures only sulfur gases released from

CDW and not frequent indoor contaminants such as salt air, ammonia, moisture or bleach.

Corrosion Testing = CDW Gases

Page 55

Again, while direct corrosion measurements by SDT measures only sulfur gases released from CDW and not frequent indoor contaminants such as

salt air, ammonia, moisture or bleach.

Other corrosion measurement systems such as CheckMate are not reliable because they

measure total corrosion (including corrosion from salt air, ammonia, bleach moisture) and not

corrosion only from CDW gases. Many, many false positives with CheckMate. Not

recommended.

CheckMate Corrosion Testing = ALL Gases Not Just CDW Gases



Dual Nature of CDW Off-Gassing

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• Dennis Hooper, M.D. Ph.D. and RealTime Labs have characterized the bacteria found in Chinese drywall using DNA profiling techniques.

• Such bacteria metablize sulfur compounds and off-gas the corrosive gases found in problem CDW homes.

• Hooper et at Int. J. Mol. Sci. 2010, 11, 647-655; doi:10.3390/ijms11020647

Third Party Research on Chinese Drywall Bacteria

World renowned researcher doing DNA profiling of sulfur bacteria in Chinese drywall.


Page 58

The complex off-gassing pattern (its so-called off-gassing fingerprint) from corrosive CDW shown above (analyzed using an Agilent 6890N GC on my visit to Centek Labs 6-15-09) looks markedly like the complex off-gassing fingerprint seen in landfills that is known to be a result of sulfur producing bacteria.

Bacterial Off-Gassing Fingerprint


Page 59

Bacterial Off-Gassing

The off-gassing fingerprint produced by

corrosive drywall is markedly similar to the gas release fingerprint known to be the result of

sulfur bacteria metabolism in landfills.

How else do you explain such similar fingerprints other than sulfur bacteria in both

landfills and drywall?

There are no other explanations!


Page 60

Dual Nature of Chinese Drywall Off-Gassing

• As proposed in June 2011 by Dr. Gary Rosen, PhD (author of this report) the cause/ nature of problem Chinese drywall is best explained by a theory of CDW off-gassing in which two independent reactions contribute to corrosive gas release.

Bacteria, as well as

Elemental Sulfur (S8)


Page 61

S8 Corrosion: Not Humidity Dependent

• S8 release is not dependent on elevated temperature and humidity as are gases produced by bacteria in drywall.

• In the drier and cooler winter months, problematic CDW corrosion is mostly from S8 and not bacteria because (due to ambient conditions) bacteria are not as active in the winter as in the summer.


Page 62

S8 Source

• We have postulated that Elemental Sulfur (S8) was added to the drywall as a fungicide to keep mold from growing on the drywall paper during the long and wet ocean voyages from China to the US mainland.

• This is why S8 is found principally in drywall paper and not gypsum core.


Page 63

XRF Measures ONLY Sulfur Deposition

• Jack Frost, the owner of Drywall Science, LLC is the originator of the technique for using XRF to study copper coupon corrosion. This technique is called Sulfur Deposition Testing (SDT).

• By using XRF one can specifically measure the amount of sulfur compound deposited on the coupon surface.

• Earlier CPSC studies of copper coupon corrosion were based on measuring total coupon corrosion from all corrosion sources and were not specific to Chinese drywall produced sulfur gases. These studies as a result were not reliable.


Page 64

Dual Nature of Chinese Drywall Off-Gassing

• Whereas with XRF, one can measure ONLY the corrosion that results from the sulfur gases produced by corrosive CDW (measure sulfur deposition) and not corrosion from salt air; bleach fumes; ammonia; etc.

• XRF-based measurement of sulfur deposition was an important breakthrough for having a reliable method to measure copper corrosion from Chinese drywall produced sulfur gases.

• The table below is the experimental data summary taken from a Drywall Science, LLC study that heavily relies on XRF-based sulfur deposition measurements.


Page 65

Experimental Results


Page 66

Analysis of Results

• Columns #1/#2: Type/Sample - These columns list the name of manufacturer and sample numbers. Those in red are known corrosive Chinese drywall. JF2, JF6, JF7, JF12, JF13 are US drywall. BNBM (JF1) is known non-corrosive Chinese drywall.

• Column #3: Strontium Content - Based on this table, clearly any attempt to use Strontium content by itself to determine if drywall is corrosive CDW can be problematic.


Page 67

Analysis of Results

• Columns #4-#8: Sulfur Deposition (Corrosion) - Sulfur deposition in ug/cm2 over almost 1 year. JF3 and JF14 are normally corrosive Chinese drywall that do not show corrosion in this study.

• Column #8: Elemental Sulfur (S8) content – These same two types of normally corrosive Chinese drywall (JF3 and JF14) show no corrosive in this stydt and contain no Elemental Sulfur (S8).


Page 68

Big Question Here

• Why is it that in this experiment, two samples of Chinese drywall that are known corrosive do not result in accumulated copper corrosion but all the other known problem Chinese drywall do?


Page 69

Explanation of Results

• The two normally corrosive Chinese drywall samples JF3 and JF14 (marked in Red to indicate corrosive) do not contain Elemental Sulfur (S8).

• To explain the results we need to look at the conditions of the experiment - which is that it was run without humidity present (see footnote on Test Results page 65).

• No humidity means that the bacterial component in the Chinese Drywall is not active. Only the S8 corrosive off-gassing component is active with no humidity.

• No S8 (as in JF3 & JF14) means no corrosion when bacteria are starved of humidity.


Page 70

Conclusions from Results

• If S8 is not required for drywall to be corrosive (JF3 and JF4 are corrosive but contain no S8) then clearly S8 is either not the cause or not the only cause of corrosive gas release.

• Therefore, there must be another component to corrosive gas production in addition to S8.

• The other component requires both elevated temperature and humidity to be active.


Page 71

Conclusions from Results

• Since JF3 and 14 are corrosive drywall but not producing corrosive gases in this study, this behavior is best explained by assuming a micro-biological component to off-gassing that, depending on temperature and humidity conditions, can be either on or off.

• When the micro-biological component is inactive (low humidity), the S8 (chemical) component is easily seen (when S8 is present) JF4,5,8,9,10,11.


Page 72

Overall

Conclusions


Page 73

At this time the Dual Component Theory of Chinese Drywall Off-Gassing is the only

explanation to account for observed problematic Chinese drywall behavior as well

as the off-gassing fingerprint produced by problem CDW.

Corrosive gas is released by both S8 (Inorganic sulfur) and Bacteria growing in the drywall.

Supports Dual Component Theory of CDW Off-Gassing


Page 74

Direct measurement of Chinese Drywall Corrosion using Sulfur Deposition Testing will

accurately and reliably measure the contribution to corrosive gas release from

both sources.

Direct Measurement of CDW Corrosion


Page 75

The earlier corrosion testing performed by the CPSC looked at only total corrosion.

Corrosion testing using CheckMate (http://www.cosasco.com/portable-corrosion-instrument.html#products) also looks only at

total corrosion.

Neither of these forms of corrosion testing is reliable because they are not selective for

corrosion from only sulfur gases (CDW gases).

Total Measurement of CDW Corrosion NOT Reliable


http://www.cosasco.com/portable-corrosion-instrument.html






Page 76

Air sampling for Chinese drywall corrosive gases is not reliable for several reasons:

• It is much less sensitive than SDT based corrosion testing.

• There can be false positives and false negative with air sampling.

• Air sampling does not measure SO2 levels which is actually the major sulfur gas in

problem Chinese drywall homes.

Air Sampling NOT Reliable


Page 77

Sulfur Deposition Testing directly measures copper coupon corrosion from only CDW

gases.

And when used for Post Remediation Clearance Testing allows one to accurately and reliably

determine whether a home has been properly remediated whether this be by drywall

removal or by Molecular Cleanz™ treatment.

Post Remediation Clearance


Page 78

SDT is widely used. The following companies or consultants are using direct measurement of copper corrosion by XRF for reliably detecting

low or ultra low levels of sulfur gases in homes/ offices.

Chinese Drywall Screening LLC

Drywall Science LLC

Healthy Home Solutions LLC

Joe Petrauskas (Consultant)

SDT is Widely Used


Page 79

Certified Mold Free Corp is not in the business of testing homes for corrosive gases using SDT or other forms of

corrosion testing.

Our focus is CDW remediation both in-place remediation with Molecular Cleanz and by drywall removal.

An accurate, reliable, low cost method that shows successful remediation is of utmost importance to our remediation business. Hence we have spent a great

deal of time and money evaluating available methodologies.

Disclaimer


Documents

Annual Review of CDW 2012 - Molecular Cleanz Annual Review of CDW 2012 Author Gary Rosen, PhD Subject Chinese Drywall Created Date 1/2/2013 10:47:06 AM