Columbia Analytical Services

Columbia Analytical Develops Protocol for Testing Corrosion and Odor in Chinese Drywall

Chinese Drywall Odor TestSIMI VALLEY, California — Columbia Analytical Services, Inc. announces it has established a reliable test protocol for identifying odor and corrosion problems in drywall. The tests identify problems with drywall, generally reported as “Chinese drywall,” that initially affected many homes in the southeastern United States.

“Our team has developed three technically superior and legally-defensible analytical tests related to the drywall problem,” said Michael Tuday, Director of Research and Development at Columbia Analytical’s Simi Valley, California laboratory. “We have been studying the issue and testing both foreign and domestic drywall samples since February, 2008, and are excited to have found a testing solution to isolate this problem.”

The Simi Valley laboratory confirmed that hydrogen sulfide is one of the major contributing agents causing the corrosion. With its characteristic rotten egg smell, hydrogen sulfide is a likely contributor to reported odors in affected homes. Other researchers have also identified iron disulfide (pyrite) and strontium sulfide as possible corrosion culprits, as well.

Researchers at Columbia Analytical also determined the drywall in question contains a naturally occurring allotrope of elemental sulfur and have developed a novel means of quantifying orthorhombic cyclooctasulfur (S8) in drywall via analysis by gas chromatography/mass spectrometry (GC/MS). In tests to-date, this sulfur allotrope is a unique and reliable marker in drywall products causing corrosion problems and has only been found in drywall imported from China.

Columbia Analytical has developed an innovative chamber test procedure for the measurement of hydrogen sulfide at ultra-low levels in suspect drywall. To confirm corrosivity, a jar test is used to document copper corrosion in the presence of test drywall samples.

These laboratory tests may be used to confirm visual home inspections and to demonstrate that corrosion effects are due to drywall and not other items in the home, such as carpets, cleaners, paints, or personal care products.

Columbia Analytical is an employee-owned, full-service environmental analytical network with laboratories and service centers nationwide. The company’s expertise encompasses air, water, dioxin, biological, pharmaceutical, and solid and hazardous waste analyses.

For more information about drywall testing, contact the Simi Valley laboratory at +1 805 526 7161 or visit Columbia Analytical’s website at

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22 Responses to “Columbia Analytical Develops Protocol for Testing Corrosion and Odor in Chinese Drywall”

  1. Rex Heller Says:

    What GC/MS are you using?

  2. Columbia Analytical Says:

    Hello! We use an Agilent 5973 GC/MS.

  3. Eugenia Mirica Says:

    S8 is the most stable and most common of sulfur forms. In what concentration range is it present in the odorous drywall?

    Then you mention about presence of H2S. How is H2S formed in the odorous drywall? S8 is way too stable to decompose and form H2S. How do you put these two events together?

  4. Columbia Analytical Says:

    Eugenia, thank you for the question. We have found S8 to be a consistent marker in the odorous drywall. Combined with the H2S analysis provides to date definitive identification of the suspect drywall. In many cases this is referred to a Chinese drywall. We do not believe that there is interaction with the S8 forming the H2S, the exact mechanism of H2S formation is still under investigation. If you have further questions please feel free to call us.

  5. Eugenia Mirica Says:

    Where do you think S8 is coming from in gypsum? And why do you think it is bad? S8 has no odour. SO2 that is forming due to slow oxidation has. No SO2 was found, but H2S sometimes and most ofthen CS2 and COS.

    I am asking becuase I am very familiar with the analysis and it seems to me that it is not really in correlation with the findings done by other labs and in correlation with all the issues associated with this bad drywall.

  6. Columbia Analytical Says:

    We believe that the S8 is naturally occuring in the gypsum found in China. We do not consider it “bad” but more so as a marker for Chinese drywall since we have not seen the S8 in domestic drywall. CS2 and COS are found in both Chinese and domestic drywall so is not a good indicator of problem drywall.

    We performed a tremendous amount of research prior to releasing any information and that research continues today. The issue of Chinese drywall is very complex. Please feel free to contact me to discuss this further.

  7. Alice Martin Says:

    Is the strontium present in any emitted gases? I have inquired to several health professionals about having urine or blood testing for these compounds to assess how much my family may be inhaling, and was told that I wouldn’t have strontium in my system unless I ate the drywall; but if it isn’t present in the gases, how could it contribute to corrosion?

  8. Columbia Analytical Says:

    Strontum sulfide has been mentioned in other research as a possible corrosion culprit in Chinese drywall. We have no comment on that since our research was directed in a different direction. Please feel free to contact us for any other information on Chinese drywall testing or try contacting another health care professional.

  9. Eugenia Mirica Says:

    Are you familiar with the analysis performed for EPA and Fl DOH?

  10. Columbia Analytical Says:

    Yes, we reviewed the EPA report as soon as it was released. We have been in touch with personnel from EPA and FL DOH to discuss their findings and how their findings relate to our ongoing studies.

  11. D. F. Says:

    Let’s say the hydrogen sulfide is one of the major contributing agents causing the corrosion, is it likely to have any detrimental effects on any other metals or materials in the constructed building?

    Could the agents/compounds you are testing for penetrate existing materials only to be released later if the faulty gypsum board is removed and replaced.

  12. Columbia Analytical Says:

    According to the FL DOH’s “Step-by-Step Self-Assessment Guide” for Chinese Drywall, any exposed copper, brass or metallic plumbing fixtures can sometimes exhibit signs of sulfur corrosion. Also, according to the FL DOH’s “Frequently Asked Questions” (revised 5/15/09), it may be possible for some porous materials such as drywall and fabrics to absorb/re-emit corrosive vapors. It is uncertain whether the same phenomenon will occur with materials such as concrete and lumber. The effectiveness of cleaning these materials is currently unknown. Feel free to check the FL DOH website for their latest information:

  13. Edward Tighe Says:

    Have you tested drywall with the following markings? “4feetx12×1/2inch” spaces “06 0218″ spaces “025848″ stamped across the back of the drywall? The FL Department of Health has labeled this drywall as “unknown origin”. We have all the symptoms of CDW and have already replaced the air conditioner coils last October. There are no other markings or paper stripping on the dwywall. Thanks

  14. Columbia Analytical Says:

    Most of the drywall we have tested has been sent in relatively small pieces (e.g. 3″ round, 5″x5″ square); therefore many samples do not have any markings on them at all. We have not seen the markings you describe on the pieces of sample that have been sent to us.

  15. Jason H. Gauquie Says:

    Mr. Tighe,
    I used the dimension of drywall that you mentioned and have all of the same vapors and odors noted in many cases. I will, however, note that I have not removed a substantial portion of the drywall yet. I am performing the simple test with a piece of copper in a sealed container and a control sample. My supplier would not disclose who or where the drywall came from. I installed the sheets in 2005 in my home (NY).

  16. Carlos Rivera Says:

    Just wondring. When using the Jar test method, Apporimately how long till you see any changes in the coope? Are we talking days, weeks or months?

  17. Columbia Analytical Says:

    Hello, for our jar test, we incubate the sample for 21 days with elevated humidity and temperature. For most samples, the copper begins to become discolored after about two weeks. For our jar test, we always run an associated “positive control” sample (i.e. known defective drywall) along with the client sample, so the behaivor of the client sample may be compared with a known affected drywall sample.

  18. Scott Sensenbrenner Says:

    My question is that I am reading that you can test negative on a given sheet of drywall but what if they used Chinese material on other walls? I am looking at fairly large home over 4200 sq ft. Do I have to have every single sheet tested? The home is in a community (Sarasota FL) that has had some issues but not every home. What is your best advice for this? Also I placed clean copper pennies in every room as I read it is a cheap earlier indicator…do you agree with this method and how long should it take to show up?

  19. Columbia Analytical Says:

    Scott, the point you bring up is a good one–one wall in a home may be constructed using drywall that is not corrosive, while another may be constructed using corrosive material. In our experience in dealing with clients on this issue, there has been no pattern or way anyone can reliably say that “enough” samples have been collected. Also, to date, we are not aware of any guidance (i.e. from FLDOH, CPSC, or otherwise) that recommends a number of samples per sq ft. We have seen many folks collect at least one sample per room or floor in a home, depending on the layout, knowledge of construction practices used, etc. As for your suggestion of using pennies as a cheap indicator–this may work in certain situations, and certainly if you observe corrosion on the penny you know to investigate further–but I’d say that if you do not observe corrosion on the penny you cannot necessarily say that there is not a problem. A better indicator would be actual copper piping that was installed in the home at the time of construction, as opposed to a penny that was just recently introduced. Hope this helps!

  20. Bob Webster Says:

    Not that too many are reading this anymore … but to a few comments are worth making.

    1. H2S is not nearly as prevalent in many of the CDW homes as are COS and CS2.

    2. Eugenia’s question (third comment) was answered very well. Since then, we have learned that the gases are indeed being created by sulfur reducing bacteria (SRB). SRB store S8 for future “food” use much as humans store fat. It is believed the S8 marker actually confirms the SRB, though there are natural processes by which the S8 could be present, it would be a necessary condition, but not sufficient, to confirm the presence of SRB.

    3. SRB give off sulfide gases (including COS, CS2, and H2S) as a byproduct of their “digestive” process.

    4. Every confirmed case of CDW where drywall samples have been tested for SRB has returned “positive” results.

    5. There is no plausible chemical pathway to the production of the enormous quantities of sulfide gases being observed in CDW homes.

    6. The SRB are thought to have been introduced by untreated water (never use drywall made in a country where you would NOT drink the water!). The introduction could have come from the water used to make the plaster slurry or water used to make the paper products that are part of the drywall.

    It is my understanding that EPA has already confirmed (though perhaps not officially reported as yet) SRB as the source of the offending sulfide gases in CDW (contaminated drywall). If this is finally certified, then EPA would be in charge of remediation protocols as the contamination would be considered a microbial pest. It would be remarkable if politics were not involved with the delays in establishing the official determination of the source of contamination.

  21. Columbia Analytical Says:

    Thanks for your comments Bob. The debate of chemical vs. SRB pathway is definitely a hot topic and still under deliberation. We will look forward to more research publications and/or funding that can help answer these questions.

  22. Jasmine Leigh Williams Says:

    We are needing to get testing on several homes in Northwest Florida. Do you do services nationally?

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