|
|
| Line 1: |
Line 1: |
| − | Energetic Materials (EM) are chemicals used in formulations as propellants, pyrotechnics, and explosives in weapon systems, munitions and blasting agents. This article introduces these materials, major physical and chemical properties, and fate in the environment. Important chemical groups include nitroaromatics (e.g. 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (2,4-DNT), nitramines (e.g. hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetreazocine (HMX)), nitrate esters (e.g. nitroglycerin (NG), pentaerythritol tetranitrate (PETN)), and nitrocellulose (NC). Ammonium perchlorate (AP) is commonly used as a propellant in solid rock fuel and is addressed in a '''separate article '''. Insensitive munitions (IM) are energetics in newer military explosives, and are generally considered more stable than traditional explosives.
| |
| | | | |
| | <div style="float:right;margin:0 0 2em 2em;">__TOC__</div> | | <div style="float:right;margin:0 0 2em 2em;">__TOC__</div> |
| Line 6: |
Line 5: |
| | '''CONTRIBUTOR(S):''' [[Dr. Kevin Finneran]] and [[Dr. Robert Borden, P.E.]] | | '''CONTRIBUTOR(S):''' [[Dr. Kevin Finneran]] and [[Dr. Robert Borden, P.E.]] |
| | | | |
| − | '''Key Resource(s)''': [http://www.environmentalrestoration.wiki/images/f/fd/USEPA-2012-Site_characterization_for_munitions_constituents.pdf EPA Federal Facilities Forum Issue Paper: Site Characterization for Munitions Constituents, EPA/505/S-11/001, 2012.]<ref name= "USEPA2012FIP">U.S. Environmental Protection Agency (USEPA), 2012. EPA Federal Facilities Forum Issue Paper: Site Characterization for Munitions Constituents, EPA/505/S-11/001, 2012. [http://www.environmentalrestoration.wiki/images/f/fd/USEPA-2012-Site_characterization_for_munitions_constituents.pdf Report pdf]</ref> | + | '''Key Resource(s)''': [ |
| | | | |
| − | ==Explosives and Propellants==
| |
| − | [[File:KFinneran-Article 1-Table 1.PNG|450 px|thumbnail|Table 1. Common US military explosives, propellants and IM formulations.<ref name= "Thiboutot2002">Thiboutot, S., Ampleman, G. and Hewitt, A.D., 2002. Guide for characterization of sites contaminated with energetic materials (No. ERDC/CRREL-TR-02-1) U.S. Armu Environmental Center SFIM-AEC-TC-CR-200170. [http://www.environmentalrestoration.wiki/images/2/21/Thiboutot-2002-Guide_for_charac_of_Sites_Contamianted.pdf Report pdf]</ref><ref>Jenkins, T.F., 2007. Energetic Munitions Constituents on DoD Training Ranges: Deposition, Accumulation, and Appropriate Characterization Technology, In: SERDP and ESTCP Technical Exchange Meeting on DoD Operational Range Assessment and Management Approaches, SERDP and ESTCP, Arlington, VA.</ref><ref>Fung, V., Schreiber, B., Patel, C., Samuels, P., Vinh, P. and Zhao, X.L., 2012. Process Improvement and Optimization of Insensitive Explosive IMX-101. In Insensitive Munitions & Energetic Materials Technology Symposium (IMEMTS) & National Defense Industrial Association (NDIA): Las Vegas, NV, USA.</ref>]]
| |
| − |
| |
| − | Explosive materials are commonly classified according to the speed of the chemical reaction wave that propagates through the material. If the wave velocity is greater than the speed of sound (supersonic), the material is said to undergo detonation and is considered an explosive. If the wave propagation velocity is less than the speed of sound, the material is considered to undergo deflagration (rapid burning) and is often used as a propellant<ref name= "USEPA2012FIP"/>.
| |
| − |
| |
| − | Common military explosives are mixtures consisting of one or more explosive compounds including trinitrotoluene (TNT), 1,3,5-hexahydro-1,3,5-trinitrotriazine or Research Development Explosive (RDX), octrahydro-1,3,5,7- tetranitro-1,3,5,7-tetrazocine or High Melting Explosive (HMX), and 2,4,6- trinitro-phenylmethylnitramine (tetryl) and ammonium picrate. However, the US military is replacing many of these materials with Insensitive Munitions (IM) to reduce risks of accidental detonation. IM materials will burn, rather than explode, when subjected to fast or slow heating, bullets, shrapnel, shaped charges, or the detonation of another nearby munition. Important components of IM include 2,4-dinitroanisole (DNAN), nitroguanidine (NQ), 3-nitro-1,2,4-triazol-5-one (NTO) and other traditional munitions components (RDX, HMX). Common military explosives, propellants and IM formulations are shown in Table 1.
| |
| − |
| |
| − | Propellant formulations often contain several components. The primary component is often nitrocellulose (NC), which is combined with other EM compounds including nitroglycerin (NG), NQ, DNT, HMX, burn rate modifiers, binders or plasticizers, and stabilizers. Gun propellants usually are single component based (e.g., NC), double based (e.g., NC and NG), or triple based (e.g., NC, NG, and NQ).
| |
| − |
| |
| − | ==Physical and Chemical Properties==
| |
| − | [[File:KFinneran-Article 1-Figure 1.PNG|450 px|thumbnail|center]]
| |
| − | The structure, physical and chemical of explosive materials control their fate and transport in the environment. Figure 1 shows the chemical structure of common EM.
| |
| − |
| |
| − | Table 2 provides the molecular mass, aqueous solubility, Log octanol-water partition coefficient (Log K<sub>ow</sub>), and vapor pressure of common explosive materials. With the exception of NG, the major EM are solids at ambient temperatures. Although NG is a liquid, it is commonly used as a component of double- and triple-base propellants, with the solid polymeric NC. Aqueous solubility of EM varies dramatically between the different materials and can have an important influence on their mobility in the environment. Organic compounds with a high K<sub>ow</sub> are more likely to sorb to organic carbon in soil or bioaccumulate; however, EM tend to be high in nitrogen, and by definition, are strong oxidizing agents. EM materials tend to form crystals. The vapor pressure of these materials is relatively low, so volatilization is not an important removal mechanism for most EM.
| |
| − | <br />
| |
| − | {| class="wikitable" style="margin-left: auto; margin-right: auto; border: none;"
| |
| − | |-
| |
| − | ! style="background-color:#CEE0F2;"|'''Explosive'''!!style="background-color:#CEE0F2;"| '''CAS'''!! style="background-color:#CEE0F2;"|'''Formula'''!!style="background-color:#CEE0F2;"|'''Molecular Weight [g/mol]'''!!style="background-color:#CEE0F2;"|'''Aqueous Solubility at 25 C [mg/L]'''!!style="background-color:#CEE0F2;"|''' Log K<sub>ow</sub>'''!!style="background-color:#CEE0F2;"|'''Vapor Pressure at 20 C
| |
| − | [mm Hg]'''
| |
| − |
| |
| − | |-
| |
| − | | TNT|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=118-96-7 118-96-7]|| C<sub>7</sub>H<sub>5</sub>N<sub>3</sub>O<sub>6</sub>|| 227.13<sup>c</sup>|| 130<sup>c</sup>|| 1.60<sup>c</sup>|| 1.99E-4<sup>c</sup>
| |
| − | |-
| |
| − | | RDX|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=121-82-4 121-82-4]|| C<sub>3</sub>H<sub>6</sub>N<sub>6</sub>O<sub>6</sub>|| 222.26<sup>d</sup>|| 56.4<sup>i</sup> || 0.87<sup>d</sup>|| 1 to 4 E-9<sup>d</sup>
| |
| − | |-
| |
| − | | HMX|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=2691-41-0&terms=hmx 2691-41-0]|| C<sub>4</sub>H<sub>8</sub>N<sub>8</sub>O<sub>8</sub>|| 296.16<sup>a</sup>|| 4.5<sup>i</sup>|| 0.165<sup>i</sup>|| 3.3E-14<sup>a</sup>
| |
| − | |-
| |
| − | | Tetryl || [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=479-45-8&terms=tetryl 479-45-8]|| C<sub>7</sub>H<sub>5</sub>N<sub>5</sub>O<sub>8</sub>|| 287.14<sup>a</sup>|| 80<sup>a</sup>|| || 5.7E-9 (25 C) <sup>a</sup>
| |
| − | |-
| |
| − | | 2,4-DNT|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=121-14-2&terms=2%2c4-DNT 121-14-2]|| C<sub>7</sub>H<sub>6</sub>N<sub>2</sub>O<sub>4</sub>|| 182.15<sup>a</sup>|| 300 (22 C) <sup>f</sup>|| 1.98<sup>f</sup>|| 1.47E-4<sup>f</sup>
| |
| − | |-
| |
| − | | 2,6-DNT|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=606-20-2&terms=2%2c6-DNT 606-20-2]|| C<sub>7</sub>H<sub>6</sub>N<sub>2</sub>O<sub>4</sub>|| 182.15<sup>a</sup>|| 180 (22 C) <sup>f</sup>|| 1.72 or 2.10<sup>f</sup>|| 5.67E-4<sup>f</sup>
| |
| − | |-
| |
| − | | 2-ADNT|| 35572-78-2|| C<sub>7</sub>H<sub>7</sub>N<sub>3</sub>O<sub>4</sub>|| 197.17<sup>a</sup>|| 2800<sup>a</sup>|| || 4.0E-5<sup>a</sup>
| |
| − | |-
| |
| − | | 4-ADNT|| 19406-51-0|| C<sub>7</sub>H<sub>7</sub>N<sub>3</sub>O<sub>4</sub>|| 197.17<sup>a</sup>|| 2800<sup>a</sup>|| || 2.0E-5<sup>a</sup>
| |
| − | |-
| |
| − | | NTO|| 932-64-9|| C<sub>2</sub>H<sub>2</sub>N<sub>4</sub>O3|| 130.08|| 2000<sup>m</sup>|| 0.858<sup>m</sup>||
| |
| − | |-
| |
| − | | DNAN|| 119-27-7|| C<sub>7</sub>H<sub>6</sub>N<sub>2</sub>O<sub>5</sub>|| 198.13<sup>j</sup>|| 213<sup> o, p</sup>|| 1.58<sup>o, p</sup>|| 1.E-4 (25 C) <sup>j</sup>
| |
| − | |-
| |
| − | | NQ|| [http://www.commonchemistry.org/ChemicalDetail.aspx?ref=556-88-7 556-88-7]|| CH<sub>4</sub>N<sub>4</sub>O<sub>2</sub>|| 104.07|| 4,400<sup>n</sup>||-0.89<sup>j</sup>
| |
| − | 0.21<sup>l</sup>
| |
| − | || 1.00E-9 (est) <sup>j</sup>
| |
| − | |-
| |
| − | | colspan="12" style="color:black;text-align:left;"|
| |
| − | a = Thiboutout et al 2002<ref name= "Thiboutot2002"/>,
| |
| − | b = Pennington et al 2006 Final Report <ref>Pennington, J.C., Jenkins, T.F., Ampleman G., Thiboutot, S., Brannon, J.M., Hewitt, A.D., Lewis, J., Brochu, S., Diaz, E., Walsh, M.R., Walsh, M.E., Taylor, S., Lynch, J.C., Clausen, J., Ranney, T.A., Ramsey, C.A., Hayes, C.A., Grant, C.L., Collins, C.M., Bigl, S.R., Yost, S., Dontsova, K., 2006. Distribution and fate of energetics on DoD test and training ranges: Final Report . ERDC TR-06-13. Vicksburg, MS: U.S. Army Engineer Research and Development Center. [http://www.environmentalrestoration.wiki/images/0/07/Pennington-2006-Distribution_and_Fate...Final_Report.pdf Report pdf]</ref>,
| |
| − | c = EPA Technical fact sheet for TNT<ref name= "USEPA2014TNT">U.S. Environmental Protection Agency (USEPA), 2014. EPA Technical Fact Sheet - 2,4,6-Trinitrotoluene (TNT). [http://www.environmentalrestoration.wiki/images/e/ec/USEPA-2014-TNT_Technical_Fact_Sheet_Final_Report.pdf Report pdf]</ref>,
| |
| − | d = EPA Technical fact sheet for RDX<ref>U.S. Environmental Protection Agency (USEPA), 2014. EPA Technical Fact Sheet for RDX. [http://www.environmentalrestoration.wiki/images/f/f8/USEPA-2014-RDX_Technical_fact_sheet_contaminant_final_Report.pdf Report pdf]</ref>,
| |
| − | f = EPA Technical fact sheet for DNT<ref>U.S. Environmental Protection Agency (USEPA), 2014. EPA Technical Fact Sheet for DNT. [http://www.environmentalrestoration.wiki/images/c/c5/USEPA-2014-DNT_Technical_fact_sheet-contaminant-final_Report.pdf Report pdf]</ref>,
| |
| − | g = EPA Technical fact sheet for perchlorate <ref>U.S. Environmental Protection Agency (USEPA), 2014. EPA Technical Fact Sheet for Perchlorate [http://www.environmentalrestoration.wiki/images/0/0a/USEPA-2014-Technical_fact_sheet_contaminant_perchlorate_final.pdf Report pdf]</ref>,
| |
| − | h = McGrath (1995)<ref>McGrath, C.J. 1995. Review of formulations for processes affecting the subsurface transport of explosives. IRRP-95-2, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS [http://www.environmentalrestoration.wiki/images/a/a2/IRRP_95_2.pdf Report pdf]</ref>,
| |
| − | i = Monteil-Rivera et al. 2004<ref>Monteil-Rivera, F., Paquet, L., Deschamps, S., Balakrishnan, V.K., Beaulieu, C. and Hawari, J., 2004. Physico-chemical measurements of CL-20 for environmental applications: Comparison with RDX and HMX. Journal of Chromatography A, 1025(1), pp.125-132.[http://dx.doi.org/10.1016/j.chroma.2003.08.060 doi: 10.1016/j.chroma.2003.08.060]</ref>,
| |
| − | j = DNAN WEEL FINAL<ref>OARS, 2014. Workplace environmental exposure level (WEEL) 2,4-Dinitroanisole (DNAN). OARS, Cincinnati, OH. [http://www.environmentalrestoration.wiki/images/e/e6/OARS_WHEEL-2014-DNAN_WEEL_FINAL_2014.pdf Report pdf]</ref>,
| |
| − | l = DRDC 2011<ref name="DRDC2011">DRDC. 2011. Annual report 2010-2011. Environmental fate and ecological impact of emerging energetic chemicals (DNAN and its Amino-Derivatives, NTO, NQ, FOX-7, and FOX-12). Prepared by J. Hawari. NRC# 53363, Defense Research and Development Canada, National Research Council of Canada, Montréal, Québec</ref>,
| |
| − | m = NTO WEEL FINAL<ref>OARS, 2014. Workplace environmental exposure level (WEEL) 3-Nitro-1,2,4-Triazol-5-One (NTO). OARS, Cincinnati, OH. [http://www.environmentalrestoration.wiki/images/1/1d/OARS-2014-NTO_OARS_WEEL.pdf Report pdf]</ref>,
| |
| − | n = van der Schalie 1985<ref>Schalie, W.H., 1985. The toxicity of nitroguanidine and photolyzed nitroguanidine to freshwater aquatic organisms (No. USAMBRDL-TR-8404). Army Medical Bioengineering Research and Development Laboratory, Fort Detrick, MD. [http://www.environmentalrestoration.wiki/images/4/42/Van_der_Schalie-1985-The_Toxicity_of_Nitroguanidine_photolyzed_nitro.....pdf Report pdf]</ref>,
| |
| − | o = Hawari 2014<ref>Hawari, J., 2014. Annual Report 2013-2014. Environmental fate and ecological impact of emerging energetic chemicals (ADN, DNAN and its Amino-Derivatives, PETN, NTO, NQ, FOX-7, and FOX-12) and an insensitive formulation. Defense Research and Development Canada, National Research Council of Canada, Montréal, Québec. [http://www.environmentalrestoration.wiki/images/8/8b/Hawari-2014-Envl_fate_and_ecological_impact_of_emerging_energic_chemicals.pdf Report pdf]</ref>,
| |
| − | p = Hawari et al 2015<ref>Hawari, J., Monteil-Rivera, F., Perreault, N.N., Halasz, A., Paquet, L., Radovic-Hrapovic, Z., Deschamps, S., Thiboutot, S. and Ampleman, G., 2015. Environmental fate of 2, 4-dinitroanisole (DNAN) and its reduced products. Chemosphere, 119, pp.16-23.[http://dx.doi.org/10.1016/j.chemosphere.2014.05.047 doi:10.1016/j.chemosphere.2014.05.047]</ref>
| |
| − |
| |
| − | Table 2. Physical and Chemical Properties of important explosives and propellants
| |
| − | |}
| |
| − |
| |
| − | ==Health and Environmental Impacts==
| |
| − | Exposure of humans to EM compounds can result in significant health issues. High oral or dermal exposures to TNT can cause liver and blood damage, anorexia, and anemia. High oral exposures to RDX can cause neurological affects such as convulsions. Some EM can bioaccumulate in crop plants (e.g. RDX), leading to potential exposure by eating or direct contact<ref>Spain, J.C., Hughes, J.B. and Knackmuss, H.J. eds., 2000. Biodegradation of nitroaromatic compounds and explosives. CRC Press.</ref><ref>Brannon, J.M. and Pennington, J.C., 2002. Environmental fate and transport process descriptors for explosives (No. ERDC/EL-TR-02-10). Engineer Research and development Center Vicksburg, MS Environmental Lab. [http://www.environmentalrestoration.wiki/images/9/9e/TR-02-10.pdf Report pdf]</ref>. TNT and 2,4-DNT are classified as possible human carcinogens by U.S. EPA<ref name= "USEPA2014TNT"/>. In contrast, HMX is not currently classified as a human carcinogen, but has been shown to have adverse impacts on the liver and nervous system in some laboratory animals '''(ATSDR 1997)'''. The US military is replacing many of traditional explosives with Insensitive Munitions (IM) to reduce risks of accidental detonation. Since IM materials including DNAN, NTO, and NQ have not been in common use, considerable effort has been focused on understanding the toxicity of these materials '''(link to Johnson IM tox article)'''.
| |
| − |
| |
| − | There are currently no federal maximum contaminant levels (MCLs) for TNT, RDX, and HMX. Life-time health advisory levels in drinking water vary from 400 µg/L for HMX, 2 µg/L for RDX, and 2 µg/L for TNT<ref>United States Environmental Protection Agency (US EPA), 2009. Drinking water contaminant candidate list 3-final. Federal Register 74(194), 51850–51862. [http://www.environmentalrestoration.wiki/images/7/70/drinking_water_contaminant_candidate_list.pdf Report pdf]</ref>.
| |
| − |
| |
| − | ==Fate and Transport in the Environment==
| |
| − | Much of the early work on environmental issues related to EM was focused on concentrated sources including manufacturing facilities and locations where off-specification, unserviceable and obsolete munitions were destroyed<ref>Spalding, R. and Fulton, J., 1988. Groundwater Munition Residues and Nitrate near Grand Island, Nebraska, USA. Journal of Contaminant Hydrology, 2(2), pp. 139-153 [https://doi.org/10.1016/0169-7722(88)90004-6 doi:10.1016/0169-7722(88)90004-6]</ref> . More recently, attention has focused on potential contamination from military training when partial detonations deposit EM particles of range soils '''(link to Walsh article)'''. Once deposited on a range, the EM dissolves over time, a process thought to be the rate-limiting step for aqueous transport of these compounds to soil and groundwater. The mass of EM dissolved is a function of the aqueous solubility of the compound, the mass of explosive residues deposited on the soil, the size of individual residues and the three-dimensional (3D) structure of formulations that have multiple constituents '''(link to Taylor article)'''. During transport through the subsurface, EM migration is influenced by sorption to the solid phase ''' (Katerina article link) ''', as well as chemical transformation and biodegradation '''(link to Finneran bio articles)'''.
| |
| − |
| |
| − | However, the DoD has invested considerable resources to understand how these factors can be influenced, or how they operate in natural settings, to limit transport of EM in surface or groundwater. In addition, a number of remediation strategies have been developed that address EM, and have been applied both in situ and ex situ at DoD facilities.
| |
| | | | |
| | ==References== | | ==References== |
