Three Years Later: Another Look At Three Claims from UL


It has been nearly three years since I wrote a letter to the National Institute of Standards and Technology (NIST), about their World Trade Center investigation.[1] Shortly after firing me for writing this letter, my former employer, Underwriters Laboratories (UL), began making some suspicious statements.

Editor’s Note:
A chemist, fired from Underwriters Laboratories for questioning their deceptive methodologies in tests of the WTC floor assemblies post-9/11, systematically critiques the changing explanations for the collapses in the four official studies to date.

These included the following three claims related to the question of whether or not UL performed fire-resistance testing of materials used in the WTC. [2]

  1. UL vehemently denied last week that it ever certified the materials.
  2. “UL does not certify structural steel, such as the beams, columns and trusses used in World Trade Center,” said Paul M. Baker, the company’s spokesman.
  3. The company told The Tribune “there is no evidence” that any firm tested the materials used to build the towers.

One might wonder why UL felt the need to claim that there was “no evidence” if they simply do not do such work. But what is the truth about UL’s involvement in testing materials for the WTC, in terms of the fire resistance the buildings required, but apparently did not have according to the government’s fire-based “collapse” hypothesis?

UL’s first claim

Got UL Truth?Apart from steel column assemblies, there were several other materials used in the WTC towers that required fire-resistance testing in order to ensure the safety of those buildings in a fire. One such material was the fireproofing itself, and another was the floor assemblies.

James Verhalen, chairman of the company that manufactured the fireproofing, United States Mineral Products, said that ”There is no reason for that product in a typical commercial environment to deteriorate,” because “He said his product had been thoroughly tested and approved by Underwriters Laboratories.” [3]

We also know that UL consulted directly with the Port Authority’s WTC construction team, on fire resistance issues, as the towers were being built. This was described in the May 2003 NIST progress report that shows that the towers were built specifically to UL standards for fire resistance.[4] In this report NIST references a letter written in 1970 by UL management, on the subject of fire resistance of the towers, that was addressed directly to the Port Authority’s construction manager (ref. 33).

As for floor assemblies, those who have been following the NIST investigation, and various explanations, know that the current claim is that the floor assemblies used in the WTC were never tested for fire resistance. But the May 2003 NIST report says that, in 1970, UL actually tested a floor assembly that was “similar to the WTC floor system”. It is important to note that the results produced in 1970 were the same as those from the August 2004 UL floor tests – only 3 inches of sagging after 120 minutes in the furnace.

In this 2003 progress report, NIST goes on to say that they intended to perform fire resistance tests not only on the floor models, as part of the WTC investigation, but also on “individual steel members”. The latter results were never reported, and no reason was ever given. But this progress report, like NIST’s final report, focuses more on the floor assembly fire resistance, and conspicuously fails to mention the originally required fire resistance tests on steel assemblies or where these tests were performed.

UL’s second claim

Statement number two above is clearly false for several reasons. First, UL is known to be one of the few important organizations supporting codes and specifications because they “produce a Fire Resistance Index with hourly ratings for beams, columns, floors, roofs, walls and partitions tested in accordance with ASTM Standard E119.” [5]

In fact, even today you can go to UL’s website and order fire-resistance testing for building components such as “floors, roofs, walls, beams and columns.” [6]

Additionally, the WTC report from the Federal Emergency Management Administration (FEMA) said “the UL Fire Resistance Directory …is the major reference used by architects and engineers to select designs that meet the building code requirements for fire resistance ratings.” [7]

Not only that, a New York Times article about the WTC reported in April 8, 2002 that “a furnace procedure called ASTM E-119” is used to “determine if building materials will survive out-of-control blazes.” The Times went on to report “The furnace tests, conducted at places like Underwriters Laboratories here, focus on the ability of separate building components — a steel column or a concrete roof support — to survive temperatures as high as 2,000 degrees.”

This article was critical of the tests performed as they related to the WTC, but certainly didn’t deny that they were performed, and made it clear who it was that performed them by saying –“At the Underwriters Laboratory campus in this northern Chicago suburb, where workers carry out those blazing tests…”. [8]

But unless anyone doubted who performed such tests on the steel columns used in the WTC towers, UL made that clear a week later in a hasty response to the New York Times editor published April 15, 2002. UL’s own Tom Chapin, the chemist and manager of their Fire Protection division, with whom I was in contact, admitted to UL’s involvement in testing steel (i.e. that which allowed the towers to stand) for the WTC by writing — “The World Trade Center stood for almost an hour after withstanding conditions well beyond those experienced in any typical fire. In that time, thousands of people escaped with their lives. ASTM E-119 and UL’s testing procedures helped make that possible.” [9]

As if this publicly available knowledge was not enough to prove UL’s involvement in testing the steel, there are also the statements made to me by top managers at UL, including their CEO. UL’s CEO, Loring Knoblauch, made verbal statements to all staff at UL in South Bend on or about September 27, 2001. These statements included reference to UL having “certified the steel used in the World Trade Center” and that, because of this, employees should be proud of how long the buildings stood.

After being later asked for formal confirmation of such tests, Knoblauch repeated his statements again, this time in writing.[10]

“We tested the steel with all the required fireproofing on, and it did beautifully.”

“As we do not do follow-up service on this kind of product, we can give an opinion only on the test sample which was indeed properly coated.”

“We test to the code requirements, and the steel clearly met [the NYC code] requirements and exceeded them.”

After two lies, what should we make of the third claim?

Since UL is the primary company that performs fire-resistance tests of building components, and it is obvious that they were deeply involved in establishing the fire resistance of the WTC towers, why would they make the claim of “no evidence” with regard to the steel column assemblies?

One reason might be that the fact that the UL tests performed in August 2004, on models of WTC floor assemblies, roundly disproved the long-standing pancake theory. This meant that the steel column assemblies would have to take center stage in any fire-induced failure scenario and, in fact, NIST did finally decide to build their latest story around failure of the perimeter columns.

Another reason UL might have suddenly became evasive is that the draft report from NIST, that I was fired for questioning in October 2004, repeatedly stated that the WTC steel had “softened”, leading to collapse. [11] But after my letter became public, and everyone was made aware that the low steel temperatures found would not support such a claim, NIST delayed their report another seven months, and then removed all reference to the word “soften”. This suggests that the influence of public statements by a UL employee, including that UL tested the steel, changed the results of the NIST report with respect to effects of fire on the steel.

In conclusion, there is no question that Underwriters Laboratories was the central player in providing fire-resistance information for the WTC towers. This glaring fact, along with UL’s evasive and misleading behavior, indicates that discovering the details about those original tests could go a long way toward ending the debate about how the towers fell. Alternatively, continued evasion and deception by Underwriters Laboratories provides yet another reason why the fire-induced “collapse” hypothesis for the WTC towers is completely unbelievable.


1. Kevin Ryan, “The Collapse of the WTC,” 911 Visibility Project, November 11, 2004 ( ).

2. John Dobberstein, “Area Man Stirs Debate on WTC Collapse,” South Bend Tribune , November 22, 2004 ( ).

3. James Glanz And Michael Moss, A Nation Challenged: The Towers; Since the Beginning, Questions Dogged the Trade Center’s Fireproofing, New York Times , December 14, 2001

4. NIST, May 2003 Progress Report on the Federal Building and Fire Safety Investigation of the World Trade Center Disaster

5. Samuel H. Marcus, Basics of Structural Steel (Reston, Va.: Reston Publishing 1977), 20.

6. Underwriters Laboratories website, Fire-Resistive Assemblies,

7. Federal Emergency Management Administration (FEMA), “World Trade Center Building Performance Study,” May 2005, Appendix A

8. Eric Lipton and James Glanz, “A Nation Challenged: The Trade Center; Tower’s Collapse Raises New Doubts About Fire Tests”, New York Times , April 8, 2002.

9. J. Thomas Chapin, General Mgr., Fire Protection Div. Underwriters Laboratories, Letter to the editor entitled “Fire Test is Sound”, New York Times , April 15, 2002.

10. Underwriters Laboratories email correspondence, December 1, 2003.

11. NIST, Latest Findings from NIST World Trade Center Investigation Released, Leading Collapse Sequence for Each WTC Tower Defined, October 19, 2004

SOURCEKevin Ryan
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Kevin Ryan

Kevin Ryan's work as a Site Manager for the environmental testing division of Underwriters Laboratories (UL) led him to begin investigating the tragedy of September 11th, 2001. UL fired him, in 2004, for publicly asking questions about UL’s testing of the structural materials used to construct the World Trade Center (WTC) buildings as well as UL’s involvement in the WTC investigation being conducted by the National Institute of Standards and Technology (NIST).

Since 2006, he has been the co-editor of the Journal of 9/11 Studies and a founding member of several action groups. He has also served as a board director at Architects and Engineers for 9/11 Truth and co-authored several books and numerous peer-reviewed scientific articles on the subject, given public presentations around the country and continues to do research into the crimes of 9/11 in order to help people come to a better understanding.