Thermite Reaction from a Plane Crash

Ask the Expert Question:
Could the friction from a plane crash generate enough energy to start a thermite reaction?

TestAmerica Expert: Larry Penfold


Expert's Response:
Thermite reactions are chemical reactions between a zero valence metal and a metal oxide. The one I remember from my school days involved iron oxide (rust) and powdered aluminum, which requires an ignition source with a temperature of something like 2,500 to 3,000 degrees Centigrade. The reaction generates a lot of heat quickly and, unlike a paper fire, doesn’t need any air to keep it going. The oxygen that sustains the burning is coming from the iron oxide. It’s a chemistry experiment that requires extra fire precautions - I can remember a demonstration given by one of my university chemistry professors that was much more exciting than he expected.

In regards to a plane crash, the total energy of an airplane crash is certainly more than enough to start a thermite reaction. A little Fourth of July sparkler is enough if all of the ingredients are carefully prepared in the right proportions, and it is the question about the right proportions that is the key to the answer to your question.

I would guess that the aluminum skin in the nose of the crashing airplane could simply melt and burn in the atmosphere without any metal oxide being present. In other words, a spray of high temperature aluminum combining rapidly with the oxygen in the air is a likely reaction. Spontaneous combustion of materials in air is sometimes called a pyrophoric reaction, not quite the same as a thermite reaction. If there were some iron rust present where the aluminum from the nose of the plane is burning, then it could add its oxygen to the burning and there would be a little bit of a thermite reaction going on. But unless there almost as much rust as aluminum, I wouldn’t think that would be the main effect because the ratio of the ingredients, the stoichiometry, is not right.

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EPA Releases Final Health Assessment for TCE

WASHINGTON – The U.S. Environmental Protection Agency (EPA) today released the final health assessment for trichloroethylene (TCE) to the Integrated Risk Information System (IRIS) database.  IRIS is a human health assessment program that evaluates the latest science on chemicals in our environment. The final assessment characterizes the chemical as carcinogenic to humans and as a human noncancer health hazard. This assessment will also allow for a better understanding of the risks posed to communities from exposure to TCE in soil, water and air. It will provide federal, state, local and other policy makers with the latest scientific information to make decisions about cleanup and other actions to protect people's health. 

"This assessment is an important first step, providing valuable information to the state, local and federal agencies responsible for protecting the health of the American people," said Paul Anastas, assistant administrator for the EPA's Office of Research and Development. "It underscores the importance of EPA's science and, in particular, the critical value of the IRIS database for ensuring that government officials and the American people have the information they need to protect their health and the health of their children."

TCE is one of the most common man-made chemicals found in the environment. It is a volatile chemical and a widely used chlorinated solvent. Frequently found at Superfund sites across the country, TCE’s movement from contaminated ground water and soil, into the indoor air of overlying buildings, is of serious concern. EPA already has drinking water standards for TCE and standards for cleaning up TCE at Superfund sites throughout the country.

TCE toxicity values as reported in the assessment will be considered in:

·         Establishing cleanup methods at the 761 Superfund sites where TCE has been identified as a contaminant

·         Understanding the risk from vapor intrusion as TCE vapors move from contaminated groundwater and soil into the indoor air of overlying buildings

·         Revising EPA’s Maximum Contaminant Level for TCE as part of the carcinogenic volatile organic compounds group in drinking water, as described in the agency’s drinking water strategy

·         Developing appropriate regulatory standards limiting the atmospheric emissions of TCE – a hazardous air pollutant under the Clean Air Act

This assessment has undergone several levels of peer review including, agency review, interagency review, public comment, external peer review by EPA’s Science Advisory Board in January 2011, and a scientific consultation review in 2006 by the National Academy of Sciences. Comments from all reviewers are addressed in the final assessment.

EPA continues to strengthen IRIS as part of an ongoing effort to ensure concrete research and science are used to protect human health and the environment. In May 2009, EPA restructured the IRIS program to reinforce independent review and ensure the timely publication of assessments. In July 2011, EPA announced further changes to strengthen the IRIS program in response to recommendations from the National Academy of Sciences. EPA’s peer review process is designed to elicit the strongest possible critique to ensure that each final IRIS assessment reflects sound, rigorous science.

More information on IRIS: http://www.epa.gov/IRIS

Exposure Assessment Planning

Ask the Expert Webinar Series
September 15, 2011
1:30 P.M. EST

Exposure assessments are conducted for a variety of reasons. The design of the strategy should be consistent with the underlying purpose of the assessment and how the resulting data will be used. Collecting samples without fully understanding how the results will be utilized and communicated can result in obtaining information that maybe misinterpreted or misleading. Prior to collecting field samples, it is necessary to clearly understand the purpose and objectives of sampling projects.

The purpose of the data collection, in conjunction with the availability and cost of field and laboratory analytic techniques, as well as the time sensitivity of the results, will determine the overall sampling strategy. This presentation provides a basic overview of the planning elements that are important to conducting a productive, cost effective and successful exposure assessment.

Register Now for the presentation



Visit TestAmerica at the 2011 SAME Missouri River/ TEXOMA Regional Conference

August 23-25, 2011

Downtown Marriott

Kansas City, MO

TestAmerica has more than 20 years of technical and industry experience with the analysis of trace explosives and compounds unique to the military, supporting hundreds of special projects under various programs domestically and internationally.

TestAmerica provides analytical testing to assist with clean-up activities for a variety of clients, regulatory officials, and stakeholders from every segment of the Department of Defense, and is the nation’s:

• Only network with 13 DoD QSM Compliant laboratories
• First laboratory to receive USACE approval for Method 8330B in support of MRP
• First laboratory to be DoD ELAP accredited
• Leader in developing applications of Incremental Sampling Methodology (ISM) to an expanding range of chemicals of interest to the DoD.

Stop by Booth # 105 to learn more about TestAmerica’s:

• DoD ELAP accredited laboratories
• ISM expertise and capabilities - 8330B and beyond
• Methods for conventional explosives and the new insensitive munitions constituents

Sign up now for our free webinar on Insensitive Munitions Constituents on Thursday, August 25th at 1:30 P.M. EST.

Pharmaceutical and Personal Care Products Challenges in Non-Conventional Matrices

Ask the Expert Webinar Series
August 18, 2011
1:30 P.M. EST


Pharmaceuticals and personal care products (PPCPs) represent a large subset of contaminants of emerging concern labeled as endocrine disruptors. The endocrine system is a balanced network of glands and hormones that regulates developmental activities such as growth, behavior, metabolism, intelligence, sexual development, and the ability to reproduce as well as many other functions. To date, many studies have characterized the PPCP contamination in rivers and lakes across the country, and as the effects of these contaminates are unfolding, researchers are looking beyond water ways for these chemicals.

TestAmerica continues to partner with public and private researchers looking for PPCPs as they pass from non-point sources into sensitive ecosystems. Our method development has expanded our PPCP testing capabilities into sediment and tissue samples to find these contaminants where endocrine disruption is occurring. Making the leap from testing water to more complex matrices requires solutions for increased matrix related interferences and extraction enhancements that effectively remove the target compounds from the sample. Our success with complex matrices is helping answer difficult questions where PPCP contamination may be lurking.

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NORM Issues in Oil and Gas Exploration

Ask the Experts Webinar Series
August 4th, 2011
1:30pm EST

With radiation in space and beneath the surface of the earth, we live our lives in peace and harmony with our environment while surrounded by radiation. However, what risks do we take when we drill into the earth's surface for precious natural resources such as shale oil and gas?

Naturally Occurring Radioactive Material (NORM) as well as a variety of radioactive elements are present within the earth's crust at a relatively shallow depth. When drilling and mining exploration activities take place, these radioactive elements enter our waste streams and present challenges for the operators and regulators alike.

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Calculation of a Metals Oxide Compound using a Metals Analysis

Ask the Expert Question:
Can an Oxide of a metal (i.e. Barium Oxide) be determined by running a metals analysis for barium and then using a calculation to get barium oxide?

Experts Response:
The calculation is pretty straightforward, but it does involve some assumptions.

We will start with the example you cited with barium. Barium has an atomic weight of 137.34, and it normally has an oxidation state of +2. It is one of the alkaline earth metals in the second column of the periodic table, and all of these metals tend to have an oxidation state of +2. In minerals oxygen always has an oxidation state of -2. As a result, one barium atom will combine with one oxygen atom to create barium oxide, BaO. Barium oxide has a molecular weight of 137.34 + 16 (for the oxygen) which equals 153.34. If we assume that all the barium is in the oxide form, then the barium oxide concentration is as follows.

Ba concentration x (153.34/137.34) = BaO concentration

This case is pretty straightforward. With iron, however, you also end up making an assumption about the oxidation state of the metal. You could have Fe in either the +2 or +3 state. The resulting oxides would either be FeO (is Fe is in the +2 state) or Fe2O3 (if Fe is in the +3 state.). If you are calculating these as oxides, I think it is reasonable to assume that the metals are fully oxidized, so we will use the +3 state.

For iron, we will calculate the ratio of the molecular weight of Fe2O3 over the amount of iron in each molecule (2 atoms). Iron has an atomic weight of 55.847.

Molecular weight of Fe2O3 = (2 x 55.847) + (3 x 16) = 150.694

Weight of iron = 2 x 55.847 = 111.694

So, like the barium example above, here is the calculation to determine the amount of Fe2O3 based on the measured Fe concentration.

Fe concentration x (150.694 / 111.694) = Fe2O3 concentration

NOTE: These calculations would present the maximum possible concentration of barium oxide – for example if the sample contained barium sulfate or barium carbonate (or any other form of barium) then the concentration of barium oxide would be overstated.

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