Discussion Page for:

Frank R. Greening, Timothy N. Greening

Characterization of a World Trade Center Dust Sample

First Published: Scientific Method 9/11, August/2017, Version 1

View Author Details for: Greening F, Greening T

Discussion for Version 1, August/2017

Comment 1: - By: the Moderators, - Received: 08/04/17 - Posted: 08/04/17 - Added To: 08/29/17, 09/06/17

This previously-unpublished paper, Characterization of a World Trade Center Dust Sample, by F.R. Greening and T.N. Greening is listed here to encourage discussion and further research of the WTC dust or powder in the context of published results and analysis by other scientists and institutions. References [13] and [14] cited by the authors can be accessed using these links: [13] and [14].

Following September 11, 2001 (9/11), Congress in 2002 charged the National Institute of Standards and Technology (NIST) with determining how and why three steel-framed buildings in the World Trade Center (WTC) - the Twin Towers (WTC1/2) and Building 7 (WTC7) - collapsed. Never before or since 9/11 had steel-framed buildings been so completely destroyed purportedly by fire.

The NIST reports for the Twin Towers were published in 2005. In these reports, NIST violated the scientific method by failing to examine the actual fall of the Towers, as well as by ignoring other pertinent evidence from before and after the destructions. Observation and analysis of the way a building falls is usually the best indicator of the reason for its collapse or destruction. By the time NIST published its WTC1/2 reports, hundreds of highly-qualified scientists, engineers, architects and other scholars had concluded, after analyzing all available evidence, that the Towers (as well as WTC7) had been brought down by some form of controlled demolition.

Another major step in proper forensic investigations of completely-destroyed buildings is to analyze a building’s remains to determine whether explosives are present. National Fire Protection Association (NFPA) guidelines require this in cases of high-order damage. However, NIST itself never made such an examination. This examination was instead performed by others, such as the United States Environmental Protection Agency (EPA) [1], RJ Lee Company [2], the United States Geological Survey (USGS) [3] and independent scientists including Niels Harrit, Jeffrey Farrer, Steven E. Jones, and Kevin Ryan [4] who examined the WTC dust or powder. All of these studies found a high percentage of iron microspheres which require high temperatures for their formation. Harrit, Farrer et al.[4] also found red/gray chips where the red layer exhibited the properties of super-thermite incorporating nanotechnology, a material with explosive and incendiary properties.

Comments on the paper by F.R. Greening and T.N. Greening are invited.

Notes (Added 08/29/17, 09/06/17):

In considering the Greenings' paper for listing, we asked Frank Greening this question: "Did you look for any of the red-gray chips found in other WTC dust samples by Harrit et al.?" Frank Greening replied: "I spent a lot of time looking for red-grey chips, but found none. And I did find a few mono-layered iron-oxide chips." Regarding his work at McMaster University, Greening stated: "I paid $600/hour out of my own pocket for the SEM work." Greening also stated that this was the first WTC dust sample that he had analyzed, and that Ms. Sakoutis, who supplied the dust sample, heard of his interest in analyzing WTC dust samples after she saw Greening in the 2015 Smithsonian T.V. show "Missing Evidence".


[1] Paul J. Lioy et al., "Characterization of the Dust/Smoke Aerosol that Settled East of the World Trade Center (WTC) in Lower Manhattan after the Collapse of the WTC 11 September 2001," Environmental Health Perspectives, Volume 110, Number 7, July 2002.

[2] R.J. Lee Group, Inc., "Damage Assessment 130 Liberty Street Property - WTC Dust Signature Report," December, 2003.

[3] Gregory P. Meeker, Amy M. Bern, Heather A. Lowers, and Isabelle K. Brownfield, "Determination of a Diagnostic Signature for World Trade Center Dust using Scanning Electron Microscopy Point Counting Techniques," USGS Open File Report 2005 – 1031, (2005).

[4] Niels H. Harrit, Jeffrey Farrer, Steven E. Jones, Kevin R. Ryan, Frank M. Legge, Daniel Farnsworth, Gregg Roberts, James R. Gourley and Bradley R. Larsen, "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe," The Open Chemical Physics Journal, 2009, 2,7-31.

See also a number of papers referenced in the paper under discussion.

Comment 2: - By: Christine Sakoutis, - Received: 08/03/17 - Posted: 08/09/17

I am the person who provided the 9/11 dust samples to Professor Frank Greening who has recently submitted a dust analysis to you. If anyone requires verification from me please refer to my email and ask them to write 9/11 in the title.

If you have any questions please do not hesitate to contact me. Thank you.

Chris Sakoutis

[Moderator Note: In response, the moderators wrote the following to Ms. Sakoutis:
"Dear Ms Sakoutis,
Thank you very much for contacting us and confirming the origin of the WTC dust sample that is the subject of the paper by F.R. Greening and T.N. Greening. Thank you for your thoughtfulness in preserving some of the dust you acquired that day. As you may know, our website engages in scientific discussion of submitted papers with the purpose of determining what took place on 9/11. We are in contact with other independent scientists who may be interested in examining WTC dust samples. Would you be able and willing to provide samples, similar to the one you gave Dr. Greening, for examination by other scientists? Thanks again for contacting us, this is an important part of the ongoing 9/11 research."]

Comment 3: - By: Frank R. Greening, - Received: 08/10/17 - Posted: 08/24/17

[Moderator Note: In this comment, Frank Greening is addressing the paper cited in reference [4] of Comment 1.]

As described in an Open Chemical Physics Journal article published in April, 2009, N. Harrit and S. Jones, (H&J), and seven additional authors, claim to have found “nanothermite” residues in samples of WTC dust. The authors base their study on the analysis of four samples collected at different locations in Lower Manhattan shortly after September 11th, 2001. The sampling locations are described in the paper as follows:

  1. Sample No. 1: Cedar and Liberty Streets, about 200 meters from Ground Zero
  2. Sample No. 2: Brooklyn Bridge, near Pearl Street, about 1000 meters from Ground Zero
  3. Sample No. 3: Hudson and Duane Streets, about 750 meters from Ground Zero
  4. Sample No. 4: Hudson and Chambers Streets, about 700 meters from Ground Zero

It is claimed in the Harrit et al. paper that an active thermitic material has been found "in all four samples" in the form of red/grey chips "with major dimensions of roughly 0.2 to 3 mm". Figure 2 of the Harrit paper shows examples of red/grey chips from each of the four dust samples. The single red/grey chip from sample No 1, with a length of ~ 2.5 mm, is stated to be one of the largest removed from any of the samples. Certainly, this is consistent with the examples of red/grey chips in Samples 2, 3 and 4 which exhibit lengths mostly ~ 200 microns. Nevertheless, other relatively large red/grey chips, not from Sample 1, are also discussed in Harrit et al. Some of these particles are from Sample 2, as shown in Harrit’s Figures 3 and 12. Several particles with major dimensions in excess of 300 microns are visible in Figure 3; in addition, the single particle shown in Figure 12, also from Sample 2, is approximately 750 microns in length. And finally, Figure 31 in the Harrit paper shows a particle from Sample 3 that is over 800 microns in length.

What is quite striking about the red/grey “chips” described in the Harrit et al. paper is that the authors do not consider the size of a given particle in relation to the distance of its sampling location from Ground Zero. However, aerodynamic stresses acting on particles falling in air dictate that particles with diameters greater than 1 mm fall rapidly, (with terminal velocities > 5 m/s), while very small particles, e.g. those with diameters 1 micron or less, may be held in suspension for periods greater than 10 minutes. As I have shown in my WTC Dust Characterization paper, WTC dust found at increasing distances from Ground Zero would have been significantly size-segregated as it was dispersed and gravitationally settled over Lower Manhattan; therefore, samples collected well away from Ground Zero cannot be representative of average WTC dust with respect to their particle size distribution and chemical composition. And, indeed, particles with diameters > 500 microns found in dust collected at distances > 500 meters from ground zero, could not be debris from the collapse of WTC 1, 2 or 7. Nonetheless, Harrit and Jones have, at different times, made very questionable estimates of the amount of nanothermite they believe was pre-planted in the Twin Towers using linear extrapolations from the concentrations of alleged nanothermite fragments found in WTC dust samples. (See for example: "Question No. 1" on page 23 of the Harrit paper.).

The record shows that in all their public declarations and writings on the red/grey chips, Harrit and Jones have completely ignored the size-segregating effects of gravitational settling. In truth, however, Harrit and Jones’ own data shows that the red/grey chips found in WTC dust samples, (which were collected at an average distance of 600 meters from Ground Zero), are typically in the size range 300 +/- 200 microns. However, calculations of the dispersion of dust particles in the size range 10 – 1000 microns, show that about 90 % of the 300-micron diameter particles created by the collapse of the Twin Towers would have settled well within a 600-meter radius of Ground Zero. This means that Harrit et al’s hypothesis suggesting that 10 – 100 ton of nanothermite was pre-planted in the WTC complex prior to 9/11, would have to be revised and increased by a factor of ~ 10 to allow for the size-dependent dilution effects that control dust cloud dispersion and deposition; thus, Harrit’s hypothesis requires the use of unreasonable amounts of pre-planted explosive in the destruction of the Twin Towers.

In view of the obvious logistical problems with the use of massive amounts of nanothermite it is necessary to reject Harrit and Jones’ controlled demolition hypothesis and seek alternative explanations for the nature of the iron-rich red/grey chips found in the WTC dust. One possibility is that the chips are flakes of spalled iron oxide from so-called weathering steels such as A-242 or A-588 – steels frequently used in the construction of high-rise buildings, bridges, etc. Iron oxide fragments from these steels would be quite common in the particulate matter found in any large urban center such as New York City. Recent research by Japanese scientists such as T. Nishimura has revealed the presence of nano-scale network structures of Fe(O,OH)6, incorporating surface layers enriched in alloying elements such as Al, Si, Ni and Cu, in oxide films on a number of long-exposure weathering steels. (See for example: Materials 2017, 10, 199).

Comment 4: - By: Christine Sakoutis, - Received: 08/14/17 - Posted: 08/24/17

I have more dust. Plenty of it. I promised Frank Greening that he would be in charge of distribution so please contact him. He too has more dust.

[Moderator Note: The comment previously here has been moved to the Notes section in Comment 1.]