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This previously-unpublished paper, Characterization of a World Trade Center Dust Sample, by F.R. Greening and T.N. Greening is listed here to encourage discussion and further research of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.]

Comment 5: - By: John D. Wyndham, - Received: 09/10/17 - Posted: 10/10/17

This paper by F.R. Greening T.N. Greening, herein referred to as the “Greenings’ paper” or “G&G,” presents several main issues:

  1. An examination of a WTC dust sample and the particles found therein.
  2. A discussion of temperatures in the Twin Towers during the event.
  3. A theory of how the WTC dust or powder was created.
  4. A theory of how the dust was dispersed and settled over lower Manhattan.

Main issue #1 which makes up the bulk of the paper will be of particular interest to those who have actually examined WTC dust samples using SEM/EDX equipment. Main issues #2 through #4 play important roles in the Greenings’ analysis of the results and the conclusions they reach in the paper. These specific issues will be discussed in later comments.

At a more general level, the paper raises questions about G&G’s research approach and the study of WTC dust samples now and in the future. These general issues are discussed in this comment.

Limited Scope of the Greenings' Paper

G&G’s paper makes no mention of the work of independent scientists such as Niels Harrit, Jeffrey Farrer, Steven Jones, Kevin Ryan and their collaborators who have studied WTC dust samples and written papers on their findings [1]. G&G also omits to mention studies of the air and temperatures at the WTC site (Ground Zero) by these researchers [2] [3]. At no point do G&G mention the controlled demolition theory for the WTC building destructions, although in their references [13] and [14] controlled demolition is mentioned in passing and by way of a reference to the work of Eric Hufschmid. The controlled demolition theory is held by thousands of independent scientists, architects, engineers and other scholars. See, for example, the articles in the Journal of 9/11 Studies and Architects & Engineers for 9/11 Truth [4] [5].

An internet search for F.R. Greening (and also comment 3) shows that author F.R. Greening is well-acquainted with the large body of research that supports the controlled demolition of WTC1/2, yet the G&G paper avoids any mention of it [6]. G&G's paper and references neither establish their gravity-driven theory nor do they effectively refute controlled demolition. By failing to deal adequately with the controlled demolition theory or establish their own theory, G&G’s paper does not conform with the scientific method which requires all evidence and possible hypotheses be considered.

Greenings' Omission of Results

The accurate logging and reporting of what took place during an experiment is essential to good science. According to F.R. Greening, the G&G authors spent considerable time searching for the red/gray chips reported by Harrit, Farrer et al., yet omitted to include any mention of this search in their paper. See Notes in Comment 1. A description of the methods used in their search might provide some insights into why G&G failed to find any red/gray chips. The details of G&G’s search for red/gray chips are an important part of their experiment and for completeness warranted inclusion in the paper.

The Control of Dust Samples

This is the first WTC dust sample that F.R. Greening has studied (see Notes in Comment 1). In Harrit el al., Steven Jones recounts how he obtained dust samples from Tom Breidenbach, Frank Delessio, Jody Intermont, Janette MacKinlay, and Steve White, and from an anonymous collector. Harrit et al. then states (p. 9): “Samples of WTC dust from these and other collectors have been sent directly from collectors to various scientists (including some not on this research team) who have also found such red/gray chips in the dust from the World Trade Center destruction.” If Greening was not one of the scientists to receive such samples, could he and other scientists like him obtain samples directly from the named collectors at this time? A sharing of samples, especially in cases where conflicting results are reported, would benefit this research.

According to Christine Sakoutis, F. R. Greening has control of the distribution of dust samples owned by her (see Comment 4). This raises an important issue. To avoid all conflicts of interest and even the appearance of such a conflict when distributing samples, it would be preferable if no one but the collector and the requestor were involved in the transaction. It is likely that most scientists, if they were to seek a dust sample for study, would prefer to obtain it directly from a collector who has no special relationship with any other scientist, rather than from one who has such a relationship.

The provenance of WTC dust samples is a major concern. In the interests of fair and open inquiry, how dust samples are stored and distributed without creating real or apparent conflicts of interest is of importance. There may be no easy solutions here, but the scientific community should attempt to rise above partisan considerations to ensure a credible supply of samples.

The Need for Additional Independent WTC Dust Analyses

According to Harrit et al., other scientists besides the authors of that paper have studied WTC dust samples and confirmed the presence of the red/gray chips. However, none of these scientists have as yet published their results. It would be highly important for them to publish their results without further delay. This is the only valid way to confirm or dispute the findings of Harrit et al. Theoretical arguments as to why a laboratory result should not have been observed must defer to the results of actual experiments. According to Harrit et al. (p. 9) the red/gray chips are “typically small but readily discernible by eye due to their distinctive color.”

It would be important to know at this time who else has confirmed the presence and properties of the red/gray chips. It is surprising that no major effort to confirm Harrit el al.’s findings through independent scientists publishing other studies of the red/gray chips has occurred in the period since 2009, the year Harrit et al. was published. Perhaps lack of expertise in this area, lack of access to the required equipment, time constraints and possible costs (F. R. Greening quotes a cost to himself of $600/hour - see Notes in Comment 1) have been deterrents in the confirmation process.

In their writings, both Steven Jones and Frank Legge called for the submission of WTC dust samples by collectors to interested scientists [7] [8]. At this time, it's appropriate to call for a fair distribution process for dust samples, and the publication of dust studies by as many independent scientists as possible.


[1] 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.

[2] Kevin R. Ryan, James R. Gourley and Steven E. Jones, "Environmental anomalies at the World Trade Center: evidence for energetic materials," The Environmentalist, 29 (2009): 56-63. (Also online August 4, 2008).

[3] Steven E. Jones, Jeffrey Farrer, Gregory S. Jenkins, Frank Legge, James Gourley, Kevin Ryan, Daniel Farnsworth, and Crockett Grabbe, "Extremely high temperatures during the World Trade Center destruction," Journal of 9/11 Studies, January, 2008.

[4] Journal of 9/11 Studies, "Journal of 9/11 Studies"

[5] Architects & Engineers for 9/11 Truth, "Architects & Engineers for 9/11 Truth"

[6] 911Blogger, "Dr. Frank Greening Agrees to Debate 9/11 Skeptics" National 9/11 Debate, 2006.

[7] Steven E. Jones, "Why Indeed Did the WTC Buildings Completely Collapse?" Journal of 9/11 Studies, Vol 3: September, 2006.

[8] Frank Legge, "Science of 9/11" The Case, Introduction: Notes on NIST.