Re: testing the house

Hello Jason,

Thanks for sharing that report.

Unfortunately, it appears that they may have only did half the job, and may have been in a hurry to do it. High concentrations of chlorine dioxide gas can be corrosive, especially when those concentrations are held for an extended period of time. However, I found it interesting that there was no difference between the corrosion found in the sections of the house that were flooded, and other areas of the house. That leaves the question if the corrosion was caused by the flooding and time spent with the house wet and closed up, or if the chlorine dioxide gas contributed to the corrosion.

You may find this article adds to the other article by showing some pictures of the corrosion.

http://www.sse.tulane.edu/forum_2007/presentations/benda_george.pdf


There are a couple of things to take note of...

In the Anthrax remediation chlorine dioxide gas was used to kill off the spores, then teams went in and wiped, vacuumed, and removed the dead spores from the office buildings. It appears that after Katrina, they used chlorine dioxide gas to kill the mold, but fell short on removing and remediating the mold, and also fell short on eliminating the moisture problem.

I would imagine that any damp house that was closed up for 3 months in that area would display signs of mold growth...

The "bleach" odor is an indicator that there is moisture present. In the presence of high moisture, chlorine dioxide gas can form sodium hypochlorite (bleach) as it breaks down. This bleach will give off an odor as long as moisture is present, or until it is wiped up.

I noticed a couple of "typo's" in the document, and have a call into the Chelsea Group to bring their attention to them. If you look on page 121 near the bottom, they state that the efficacy of chlorine dioxide is related to its PH, this should be RH. In addition they refer to a total of 9,000 PPM being pumped into the Hart building, and this should read that 9,000 PPM-hours was used to decontaminate the Hart building. The 9000 is a CT value. PPM refers to a concentration, not a quantity.

I happen to disagree with some of their conclusions. I don't think the EPA let anything "slip through." There are strict limits on exposure to chlorine dioxide gas that have been in effect for quite some time now. However, I do agree that more testing should be done to further verify efficacy against the various species, the ability of the gas to penetrate wall cavities, and any residual that could be left over afterward. In addition further testing should be done to show how chlorine dioxide gas can prevent or extremely slow down any regrowth of mold and mildew in upset conditions after remediation has been completed.

Tom Tweet