OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

OSAC 2022-S-0004

Standard Classification for 

Ignitable Liquids 

Encountered in Fire Debris 

Analysis

Ignitable Liquids, Explosives, and Gunshot Residue Subcommittee

Chemistry: Trace Evidence Scientific Area Committee

Organization of Scientific Area Committees (OSAC) for Forensic Science
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

2

Draft OSAC Proposed Standard

OSAC 2022-S-0004

Standard Classification for Ignitable 

Liquids Encountered in Fire Debris 

Analysis

Prepared by 

Ignitable Liquids, Explosives, and Gunshot Residue Subcommittee

Version: 1.0

October 2021

Disclaimer:

This OSAC Proposed Standard was written by the (subcommittee) of the Organization of Scientific Area 

Committees (OSAC) for Forensic Science following a process that includes an open comment period. This 

Proposed Standard will be submitted to a standards developing organization and is subject to change.

There may be references in an OSAC Proposed Standard to other publications under development by OSAC. The 

information in the Proposed Standard, and underlying concepts and methodologies, may be used by the forensicscience community before the completion of such companion publications.

Any identification of commercial equipment, instruments, or materials in the Proposed Standard is not a 

recommendation or endorsement by the U.S. Government and does not imply that the equipment, instruments, or 

materials are necessarily the best available for the purpose.

To be placed on the OSAC Registry, certain types of standards first must be reviewed by a Scientific and 

Technical Review Panel (STRP). The STRP process is vital to OSAC’s mission of generating and recognizing 

scientifically sound standards for producing and interpreting forensic science results. The STRP shall provide 

critical and knowledgeable reviews of draft standards or of proposed revisions of standards previously published 

by standards developing organizations (SDOs) to ensure that the published methods that practitioners employ are 

scientifically valid, and the resulting claims are trustworthy.

The STRP panel will consist of an independent and diverse panel, including subject matter experts, human factors 

scientists, quality assurance personnel, and legal experts, which will be tasked with evaluating the proposed 

standard based on a comprehensive list of science-based criteria.

For more information about this important process, please visit our website 

at: https://www.nist.gov/topics/organization-scientific-area-committees-forensic-science/scientific-technicalreview-panels. 
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1 Standard Classification for Ignitable Liquids Encountered in Fire Debris Analysis

2

3 This standard is issued under the fixed designation E1618; the number immediately following the designation indicates the year of original adoption 

4 or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (ε) indicates 

5 an editorial change since the last revision or reapproval. 

6

7 1. Scope

8 1.1 This standard covers the classification of ignitable liquids encountered in forensic fire debris 

9 analysis and includes classification of petroleum and non-petroleum based ignitable liquids.

10 1.2 This standard is intended for use in conjunction with approved extraction practices and 

11 instrumental test methods used to isolate and classify ignitable liquids (E1386, E1388, E1412, 

12 E1413, E2154, E2881, E3189, EXXX Interpretation).

13 1.3 This standard does not address classification complications arising from matrix contributions, 

14 microbial degradation, or weathering effects.

15 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its 

16 use. It is the responsibility of the user of this standard to establish appropriate safety, health, and 

17 environmental practices and determine the applicability of regulatory limitations prior to use.

18 1.5 This international standard was developed in accordance with internationally recognized 

19 principles on standardization established in the Decision on Principles for the Development of 

20 International Standards, Guides and Recommendations issued by the World Trade Organization 

21 Technical Barriers to Trade (TBT) Committee.

22 2. Referenced Documents

2.1 ASTM Standard:

1 23

24 E620 Standard Practice for Reporting Opinions of Scientific or Technical Experts

25 E1386 Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Solvent 

26 Extraction

27 E1388 Practice for Sampling of Headspace Vapors from Fire Debris Samples

28 E1412 Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by Passive 

29 Headspace Concentration with Activated Charcoal

30 E1413 Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples by 

31 Dynamic Headspace Concentration onto an adsorbent tube

32 E2154 Practice for Separation and Concentration of Ignitable Liquid Residues from Fire Debris 

33 Samples by Passive Headspace Concentration with Solid Phase Microextraction (SPME)

34 E2451 Practice for Preserving Ignitable Liquids and Ignitable Liquid Residue Extracts from Fire 

35 Debris Samples

36 E2881 Standard Test Method for Extraction and Derivatization of Vegetable Oils and Fats from 

37 Fire Debris and Liquid Samples with Analysis by Gas Chromatography-Mass 

1 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of 

ASTM Standards volume information, refer to the standard's Document Summary page on the ASTM website.
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38 Spectrometry

39 E2917 Standard Practice for Forensic Science Practitioner Training, Continuing Education, and 

40 Professional Development Programs

41 E2997 Standard Test Method for Analysis of Biodiesel Products by Gas Chromatography-Mass 

42 Spectrometry

43 E3189 Standard Practice for Separation of Ignitable Liquid Residues from Fire Debris Samples 

44 by Static Headspace Concentration onto an Adsorbent Tube

45 E3197 Terminology Relating to Examination of Fire Debris

46 E3245 Guide for Systematic Approach to the Extraction, Analysis, and Classification of Ignitable 

47 liquids and Ignitable Liquid Residues in Fire Debris Samples

48 WK73482 Standard Practice for Reporting Results and Opinions of Ignitable Liquids Analysis

49 WKxxxx Standard Test Method for Interpretation of Gas Chromatography-Electron Ionization Mass 

50 Spectrometry Data for the Identification of Ignitable Liquid Classes in Forensic Fire 

51 Debris Analysis

52 EXXXX Standard Practice for Gas Chromatography Electron Ionization Mass Spectrometry 

53 Analysis of Ignitable Liquids

54 3. Terminology

55 3.1 Definition of Terms Specific to This Standard:

56 3.1.1 carbon range, n.—n-alkane range, defined by the boiling points of a homologous series of 

57 n-alkanes (within n-C4-n-C20+), at which other compounds boil. 

58 3.1.2 component, n.—a compound found in an ignitable liquid.

59 3.1.3 major component(s), n.—component(s) present at the highest concentration(s).

60 3.1.4 minor component, n.—a compound present with a relative concentration of less than 5% 

61 of the major component(s).

62 3.1.5 not present, adj.—does not necessarily signify total absence of the compound or class of 

63 chemical compounds in a petroleum product. The petroleum processes used to remove or 

64 enhance specific compound classes are not always efficient and trace indications of “not 

65 present” compounds are not uncommon.

66 3.1.6 Oil and fat, n.—any oil or fat derived from plants or animals.

67 3.2 Abbreviations Specific to This Standard

68 3.2.1 Abbreviations for specific chemicals are located in Appendix A.

69 3.2.2 C# – number of carbons associated with the normal alkane or alkyl fragment for example, 

70 “C8” would refer to n-octane or octyl fragment.

71 3.2.3 EIP – extracted ion profile

72 3.2.4 FAME – fatty acid methyl ester
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73 3.2.5 HAP – heavy aromatic product

74 3.2.6 HIP – heavy isoparaffinic product

75 3.2.7 HPD – heavy petroleum distillate

76 3.2.8 KDF – key diagnostic features

77 3.2.9 LAP – light aromatic product

78 3.2.10 LIP – light isoparaffinic product

79 3.2.11 LPD – light petroleum distillate

80 3.2.12 MAP – medium aromatic product

81 3.2.13 MIP – medium isoparaffinic product

82 3.2.14 MPD – medium petroleum distillate

83 3.2.15 PNA – polynuclear aromatic

84 3.2.16 TIC – total ion chromatogram

85 4. Summary of Classification Method

86 4.1 The classification scheme contains petroleum and non-petroleum-based products resulting in nine

87 classes. Additional guidance is provided for products which do not fall into a single class. For the 

88 purposes of this standard, discussion of classification includes assignment to one of these classes.

89 4.1.1 Petroleum based ignitable liquids are classified based upon their composition resulting 

90 from common refinery processes.

91 4.1.2 Non-petroleum based ignitable liquids are classified based upon their chemical 

92 composition.

93 4.2 Examples of commercial products are provided in Table 1; however, the list is not exhaustive. 

94 Distinguishing between examples within any class could sometimes be possible, but such further 

95 characterization is not within the scope of this standard.

96 5. Significance and Use 

97 5.1 The classification of ignitable liquids is based upon the chemical composition and the carbon

98 ranges of known ignitable liquids which may be encountered in forensic fire debris analysis.

99 5.2 The ignitable liquids described herein are common to the classifications, however each ignitable 

100 liquid class contains a range of compositions. It is impractical to provide criteria for every 

101 manufactured ignitable liquid. 

102 5.3 Data analysis is based upon the analytical processes used. This standard is intended to be used in 

103 conjunction with applicable standards for the analysis (GCMS), interpretation (Interpretation),

104 and reporting of ignitable liquids (E2881, E2997, WK73482).

105 5.4 Mixtures of ignitable liquids can be marketed as a single commercial product. This standard 
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106 cannot differentiate between ignitable liquids that are mixed by a manufacturer for sale or 

107 ignitable liquids mixed at the point of use. 

108
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TABLE 1 Ignitable Liquid Classification Scheme with Examples of Known Products 1, A, B, C 109

Class Light (C4-C9) Medium (C8-C13) Heavy (C9-C20+)

Gasoline, including E85 Fresh gasoline is typically in the range C4-C12

Petroleum Distillates Petroleum ether 

Cigarette lighter fluids

Camping fuels

Charcoal starters B

Paint thinners

Dry cleaning solvents

Mineral spirits

Automotive parts cleaners

Spray lubricants

Lamp oils

Deck sealers

Varnishes

Kerosene

Insecticides

Kerosene

Diesel fuels

Charcoal starters

Aviation fuels

Insecticides

Fuel additives

Lamp oils

Automotive parts cleaners

Isoparaffinic Products

Aviation gasoline

Lighter fluids

Charcoal starters

Charcoal starters

Paint thinners

Copier toners

Mineral spirits

Solvent cleaners

Kerosene

Lamp oils

Gun oils

Spot cleaners

Penetrating oils

Insecticides

Naphthenic- Paraffinic 

Products

Charcoal starters 

Insecticide vehicles 

Lamp oils

Automotive part cleaners

Mineral spirits

Insecticides 

Lamp oils 

Aromatic Products

Paint and Varnish removers

Automotive parts cleaners

Degreasing solvents

Adhesives and adhesive 

removers

Automotive parts cleaners

Degreasing solvents

Specialty Cleaning solvents 

Insecticide vehicles 

Brush cleaners

Insecticides

Adhesives

Normal-Alkane Products

Lamp oils 

Copier toners

Wax cleaners

Lamp oils 

Carbonless paper forms

Copier toners

Oxygenated Products

Solvents (for example, Alcohols,

Ketones)

Denatured alcohols or spirits

Petroleum Products

Adhesive removers

Lacquer thinners

Enamel reducers

Paint thinners

Mineral spirits

Automotive parts cleaners

Surface preparation materials

Automotive parts cleaners

Fuel additives

Specialty solvents

Insecticides

Paint thinners

Oil and Fat-based Products Flooring Treatments

Charcoal starter fluids

Torch fuels

Olive oil, bacon grease, linseed 

oil, sunflower oil, canola oil, 

massage oils

B100 Biodiesel

Single Compounds Acetone, Ethanol, Hexane Limonene, 2-butoxyethanol

Mixtures

Enamel reducer

Paint vehicles

Lacquer thinners

Adhesive removers

Roof sealants

Mineral spirits

Lamp oils

Insecticides 
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Aviation gasoline

Racing gasoline

Fuel additives

Spray lubricants

Brush cleaners

Paint thinners

“Citrus” cleaners

Charcoal starter fluids

“Citrus” cleaners

Automotive parts cleaners

Fuel additives

Danish oil

B20 Biodiesel

Other Products Turpentine

110 A The products listed in the various classes of Table 1 are examples of known commercial uses of these ignitable liquids. These examples are not intended to be 111 all-inclusive. Reference literature materials can be used to provide more specific examples of each classification.

112 B Many of the examples can be prefaced by the word “some,” as in “some charcoal starters.” It is not unusual for similarly labeled products to have examples in 

113 more than one class, as product labeling can be based upon chemical performance or property, and not necessarily on chemical composition. 

114 C The active ingredient(s) in consumer products categorized here as “insecticides” are typically not inherently flammable, but the solvents and propellants used in 115 some consumer products can be categorized as ignitable liquids.

116 6. Data Analysis 

117 6.1. The purpose of data analysis is to locate compounds that can be indicative of an ignitable liquid 

118 class, matrix contribution or both. Evaluate the TIC and extracted ion profiles for each sample. It 

119 is important to consider the general chemical composition (e.g. by mass spectral data evaluation 

120 or through a library search report).

121 6.2. Evaluation of the Total Ion Chromatogram:

122 6.2.1. Evaluate the TIC for peaks to ensure appropriate instrument operation has occurred and 

123 data have been collected (refer to GCMS document).

124 6.2.2. Evaluate the TIC to determine the general types of compounds present and the potential 

125 identity of the major peaks using mass spectral interpretation or a commercial or validated 

126 mass spectral library.

127 6.2.3. Evaluate the TIC for the presence or absence of KDF associated with ignitable liquids. 

128 (Warning – the presence of these compounds is not solely indicative of an ignitable 

129 liquid. The relative ratios of the compounds within the groups are also evaluated.)

130 6.2.3.1. KDF include, but are not limited to (2):

131 (1) A Gaussian-like distribution of peaks.

132 (2) Patterns within a distinct boiling point range.

133 (3) A homologous series of n-alkanes or other hydrocarbons.

134 (4) A series of diagnostic aromatic patterns.

135 (5) Abundant isolated compounds.

136 6.2.4. Record this evaluation in the case record.

137 6.3. Evaluation of Extracted Ion Profiles:

138 6.3.1. EIP is valuable for the classification of ignitable liquids because it can enhance the signal139 to-noise ratio and highlight features of interest.

140 6.3.1.1. Summed ion chromatograms for two or more characteristic ions of the same 

141 chemical class can enhance the signal-to-noise ratio and decrease interference by 

142 extraneous compounds that contain only one of the ions. Additionally, summed 

143 profiles characteristic of specific classes of hydrocarbons can be created (3).
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144 6.3.1.2. Single ion extracted ion profiling can highlight a chromatographic feature of interest.

145 Note 1: Evaluating only a single ion of a compound type will not clearly present an 

146 overview of the selected chemical class distribution throughout the entire 

147 chromatogram.

148 6.3.2. There are five major hydrocarbon types associated with petroleum EIP: alkane (normal or 

149 branched), cycloalkane, alkylbenzene (also known as mononuclear aromatic), indane, and 

150 polynuclear aromatic (PNA, also known as alkylnaphthalene and condensed ring 

151 aromatic) (4, 5, 6). Other classes of compounds may be present.

152 6.3.2.1. Compounds of each type of hydrocarbon produce characteristic major ion fragments. 

153 These ions are listed in Table 2.

154 6.3.2.2. EIPs may be produced for other chemical classes such as ketones, alcohols and 

155 FAMEs. These compounds require full mass spectral comparison and retention time 

156 comparison to an appropriate standard for identification. 

157 6.3.2.3. EIPs display all peaks which contain the ions of interest. As a result, extracted ions 

158 for chemical classes can be present in a variety of EIPs. For example, the 

159 cycloalkane EIP will contain contributions from cycloalkanes, normal alkanes and 

160 isoalkanes. 

161 6.3.3. Generate EIPs for each hydrocarbon type listed in 6.3.2. 

162 6.3.4. Other ions and ion combinations, besides those listed in table 2, can be beneficial for 

163 evaluating matrix contributions.

164 TABLE 2 Major Ions of Interest for Ignitable Liquids (4, 5, 6, 9) 

Compound Type m/z

Normal/Branched Alkane 43, 57, 71, 85, 99

CycloalkaneA 55, 69, 83, 97

Alkylbenzene 91, 105, 119, 92, 106, 120, 

133

Indane 117, 118, 131, 132

PNA 128, 142, 156, 170

Ketone 43, 58, 72, 86

Alcohol

Fatty Acid Methyl EstersB

Trans-deaclin

31, 45

67, 74, 79

138

A 165   Alkenes share these ions, are not common in ignitable liquids, but are common in matrices

B 166 FAMEs should be screened for in products containing HPDs and other potential mixtures

167 7. Basis for the Classification of Ignitable Liquids (KDF) (2, 7, 10)

168 7.1. Ignitable liquids are separated into classes based upon chemical composition. These classes are 

169 gasoline, petroleum distillates, isoparaffinic products, naphthenic-paraffinic products, aromatic 

170 products, normal alkane products, oxygenated products, petroleum products, and oil and fat171 based products. Single components, mixtures, and non-classifiable products are described and 

172 classified according to their chemical composition.

173 7.2. Guidance is provided for those ignitable liquids that do not fall into one of the definable ignitable 

174 liquid classes or which fall into multiple classes. Refer to Sections 15, 17, and 18 for further 

175 information.
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176 7.3. The KDFs listed in the following sections are based on neat liquids and are meant to highlight 

177 indicative features for the ignitable liquid classes. They are not meant to be an exclusive list.

178 7.4. Products within classes can contain petroleum based and non-petroleum based components. The 

179 products within each ignitable liquid class have relatively consistent compositions based on 

180 refining, manufacturing, or both processes. 

181 7.5. With the exception of gasoline, each ignitable liquid class is further subdivided into three 

182 subclasses based on carbon ranges.

183 7.5.1. Light Product Range—n-C4-n-C9; major peaks have boiling points in the range n-C4-n-C9; 

184 no peaks associated with a boiling point above n-C11.

185 7.5.2. Medium Product Range—n-C8-n-C13; narrow range products; majority of the peaks have 

186 boiling points in the range of n-C8-n-C13; no major peaks associated with the ignitable 

187 liquid exist with a boiling point below n-C7 or above n-C14.

188 7.5.3. Heavy Product Range—n-C9-n-C20+; broad range or higher carbon range products; 

189 majority of the peaks have boiling points in the range n-C9–n-C23. When there are fewer 

190 than five n-alkanes in a product, the most volatile compounds have boiling points greater 

191 than or equal to n-C11.

192 7.5.4. A product can be characterized as “light to medium” or “medium to heavy” when the 

193 carbon number range does not fit into a subclass. 

194 7.6. The individual EIPs will be consistent among all ignitable liquids in comparable boiling point 

195 ranges within a classification. The inter-profile and intra-profile ratios may change depending on 

196 the product of origin; however, generally the peaks displayed in each of the profiles are 

197 consistent.

198 7.7. The appendix contains images of various classifications labeled with their corresponding KDFs; 

199 tables which contain the legend for the image labels are also included.

200 8. Key Diagnostic Features of Gasoline

201 8.1. This classification covers all brands and grades of gasoline, including E85. It is a blend of 

202 refinery stream products that results in distinctive chemical characteristics that allow for 

203 classification as a specified commercial product. The carbon range is dependent upon several 

204 factors including legal restrictions and environmental market. In general, the predominant 

205 features of the petroleum base of unevaporated gasoline spans within the carbon range of n-C4-

206 n-C12 and is characterized by alkylbenzene compounds extending from toluene to C5-

207 alkylbenzenes. More volatile additives, including oxygenated compounds, may be present. 

208 Gasoline can also contain aliphatic compounds that can dominate the pattern in the lightest 

209 boiling point range. When present, aliphatic compounds will have a lesser relative abundance 

210 compared to the alkylbenzene compounds following toluene. 

211 8.1.1. Octane enhancers—Depending upon evaporation, octane enhancers should be present as 

212 oxygenated compounds (for example, ethanol), alkylates, or combinations of both. 

213 8.1.1.1. Alkylates are narrow carbon range refinery products which are comprised mostly of 

214 isoalkanes (11). 

215 8.2. TIC—The chromatographic patterns for gasoline, including E85, are characterized by abundant 

216 alkylbenzenes in consistent diagnostic peaks and peak patterns (refer to appendix X1.1). 

217 Gasoline contains compounds that extend from the light range through the heavy range for 

218 ignitable liquids. 

219 8.2.1. Highly evaporated gasoline (over approximately 90 % evaporated) may not contain some 

220 of the early eluting KDF. 
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221 8.2.2. Some gasolines may not contain the later eluting compounds. 

222 8.2.3. Except for E85, the TIC of gasoline is dominated by aromatic compounds. 

223 8.2.3.1. E85 gasoline is dominated by abundant ethanol; however other KDF are consistent 

224 with non-E85 gasoline

225 Note 2: while it is classified as gasoline, E85 gasoline is reported as a mixture of ethanol and 

226 gasoline (refer to reporting WK73482). 

227 8.2.4. Oxygenated compounds are commonly added to gasoline. Methanol, ethanol, MTBE, or 

228 other oxygenated octane enhancers may not be present or observed in samples that are 

229 more than approximately 50 % evaporated. Oxygenated compounds are not added to or 

230 present in all formulations. 

231 8.2.5. Key Peaks and Groupings: 

232 8.2.5.1. Isooctane.

233 8.2.5.2. Trimethylpentane (2,3,4-trimethylpentane)(11, 18) and Toluene.

234 8.2.5.3. Three peak group comprised of the C2-alkylbenzenes.

235 8.2.5.4. Six peak group comprised of five C3-alkylbenzenes with a C10-isoalkane isomer 

236 preceding 1,2,4-TMB.

237 8.2.5.5. 1,2,4-TMB.

238 8.2.5.6. 1,2,3-TMB.

239 8.2.5.7. Indane (dihydroindene). 

240 8.2.5.8. Four peak (double doublet) group comprised of C4-alkylbenzenes with comparative 

241 peak heights between each doublet (group 1).

242 8.2.5.9. Three peak group comprised of C4-alkylbenzenes, two of which are typically 

243 unresolved, preceding the approximate retention time of n-C11 with escalating peak 

244 heights within the group (group 2).

245 8.2.5.10. Two peak group comprised of C4-alkylbenzene following the approximate retention 

246 time of n-C11 with escalating peak heights within the group (group 3).

247 8.2.5.11. Two peak group (doublet) comprised of C1-indane isomers following the C4-

248 alkylbenzenes with escalating peak heights within the group.

249 8.2.5.12. Naphthalene; may not be present in all formulations.

250 8.2.5.13. Two peak group (doublet) comprised of the C1-PNAs 2-methylnaphthalene 

251 followed by 1-methylnaphthalene with deescalating peak heights within the group.

252 NOTE 3 – These compounds may not be present in all formulations. 

253 8.3. EIP—With the exception of highly evaporated (>90 %) gasoline, in the medium range, the 

254 alkylbenzene profile is more abundant than the alkane, cycloalkane, indane and polynuclear 

255 aromatic profiles (refer to appendix X1.1). For highly evaporated gasolines the abundance of the 

256 alkylbenzene and alkane profiles may be comparable. 

257 8.3.1. Alkanes—The alkane pattern is dependent on the refinery and distribution processes. 

258 Patterns observed are typically comparable to a petroleum distillate (refer to Section 9), an
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259 isoparaffinic product (refer to Section 10) or, most commonly, a mixture of the two. 

260 Additionally, the following diagnostic alkanes should be present depending on 

261 evaporation: 

262 8.3.1.1. Isooctane.

263 8.3.1.2. Trimethylpentane (11, 18).

264 8.3.1.3. C10-isoalkane isomer in C3-alkylbenzene region.

265 8.3.1.4. Decane. 

266 8.3.2. Cycloalkanes—Can be present; however, this is not a diagnostic profile for the class. 

267 8.3.3. Alkylbenzenes—When these features are present (depending upon evaporation), they are 

268 in an overall pattern that encompasses the following diagnostic peaks and peak patterns: 

269 8.3.3.1. Toluene.

270 NOTE 4—Toluene can be present from matrix contribution. 

271 8.3.3.2. Three peak group comprised of the C2-alkylbenzenes. 

272 NOTE 5—C2-Alkylbenzenes can be present from matrix contribution. 

273 8.3.3.3. Six peak group comprised of five C3-alkylbenzenes preceding 1, 2, 4-TMB with 

274 comparative peak heights within the group.

275 8.3.3.4. 1, 2, 4-TMB—At a higher abundance than the preceding member of the C3-

276 alkylbenzene group. 

277 8.3.3.5. 1, 2, 3-TMB.

278 8.3.3.6. Four peak (double doublet) group comprised of C4-alkylbenzenes with comparative 

279 peak heights between each doublet (group 1).

280 8.3.3.7. Three peak group comprised of C4-alkylbenzenes, two of which are typically 

281 unresolved, preceding the approximate retention time of C11 with escalating peak 

282 heights within the group (group 2). 

283 8.3.3.8. Two peak group comprised of C4-alkylbenzene following the approximate retention 

284 time of C11 with escalating peak heights within the group (group 3). 

285 8.3.3.9. An C5-alkylbenzene pattern straddling the approximate retention time of 

286 naphthalene with comparative peak heights within the group.

287 8.3.4. Indanes—The following peaks and peak groupings will be present in gasoline: 

288 8.3.4.1. Indane.

289 8.3.4.2. Two peak group (doublet) comprised of C1-indane isomers following the C4-

290 alkylbenzenes with escalating peak heights within the group.

291 8.3.4.3. A four peak group comprised of C2-indane isomers where the second and fourth 

292 peaks are escalating the first and third peaks.

293 8.3.5. PNAs—Some or all PNAs may not be present in various gasoline formulations, however,

294 when present the KDFs are as follows: 

295 8.3.5.1. Naphthalene. 
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296 NOTE 6—Naphthalene can be present from matrix contribution. 

297 8.3.5.2. Two peak group (doublet) comprised of the C1-PNAs 2-methylnaphthalene followed 

298 by 1-methylnaphthalene with deescalating peak heights within the group.

299 8.3.5.3. Six peak group comprised of C2-PNA isomers in an approximately Gaussian 

300 distribution of peak heights within the group. Visualization may be limited in less 

301 evaporated samples.

302 9. Key Diagnostic Features of Petroleum Distillates (6)

303 9.1. Petroleum distillates are created by the distillation of crude oil within the distinct boiling point 

304 ranges. Some products undergo a refinery process to remove aromatic compounds. Distillates 

305 with a carbon range that start above n-C7 tend to have a Gaussian-like distribution of compounds. 

306 The homologous series of n-alkanes are the most dominant. Lighter distillates (carbon range 

307 starting before n-C7) are in the molecular size range in which fewer aliphatic isomers are 

308 possible or present. As such, isoalkane and cycloalkane peaks are comparable to normal alkane 

309 peaks. Distillates contain minor contributions to the overall pattern of aromatic compounds 

310 (alkylbenzenes, indane and polynuclear) and their presence varies based on the refining process 

311 used. 

312 9.2. Alkanes—The major peaks present are alkanes (both n-alkanes and isoalkanes). Individual n313 alkanes are more dominant than other compounds in medium and heavy distillates. In distillates

314 which have had aromatics removed, the ratio between n-alkanes and isoalkanes (and 

315 cycloalkanes) may be smaller. In medium or heavy products, if the major n-alkane peak is 

316 present at less than 1.5 times the major isoalkane or cycloalkane peak(s) height, the product is 

317 classified as a naphthenic-paraffinic product rather than a distillate (12). 

318 9.3. Cycloalkanes—Present throughout the carbon range. They are less dominant than n-alkanes and 

319 comparable to isoalkanes in medium to heavy products. In light distillates, there are single or few 

320 cycloalkane peaks, which are generally comparable to n-alkane(s). 

321 9.4. Alkylbenzenes—Aromatic compounds are present in many distillates; however, some products 

322 have had these compounds removed during the refining process.

323 9.5. Indanes—Indane, methyl indanes, and C2 indanes are present in many distillates if the carbon 

324 range of the distillate encompasses that of the compounds, however, some products have had 

325 these compounds removed during the refining process.

326 9.6. PNAs—Present in many distillates if the carbon range of the distillate encompasses that of these 

327 compounds, however, some products have had these compounds removed during the refining 

328 process.

329 Key Diagnostic Features (KDF) of Light Petroleum Distillates (LPD)

330 9.7. LPDs contain fewer compounds than heavier distillates and the pattern may not be clearly 

331 Gaussian. The pattern contains at least one normal alkane in the range of n-C4-n-C9, in which the 

332 normal alkane is more, or similar in abundance, to the isoalkanes and cycloalkane isomers. The 

333 pattern has fewer eluting peaks on the lighter end of the range due to the limited number of 

334 isoalkanes and cycloalkane isomers of the smaller molecular weight hydrocarbons.

335 9.7.1. TIC—The pattern contains a Gaussian distribution of peaks with a homologous series of 

336 spiking normal alkanes or a non-Gaussian pattern containing only one or two n-alkanes. 

337 Lighter distillates (carbon range starting before n-C7) are in the molecular size range in 
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338 which fewer aliphatic isomers are possible or present. As such, isoalkane and cycloalkane 

339 peaks are comparable in abundance to normal alkane peaks. 

340 9.7.1.1. A series of isoalkanes and cycloalkane isomers are between the consecutive n341 alkanes. The chromatographic pattern of these isoalkane and cycloalkane peaks is 

342 consistent among all distillates.

343 (1) Methylcyclohexane is present when n-C7 and n-C8 are present (12).

344 9.7.1.2. Alkylbenzenes can be present but may not be of sufficient abundance to be 

345 visualized on the TIC. The abundances vary among formulations, based on the 

346 refining process

347 9.7.2. EIP—The alkane and cycloalkane profiles are more abundant than the alkylbenzene 

348 profile (refer to appendix X1.2). Due to the carbon range, indane, and polynuclear 

349 compounds are not present. 

350 9.7.2.1. Alkanes—The pattern contains a Gaussian distribution of peaks with a 

351 homologous series of spiking normal alkanes or a non-Gaussian pattern containing 

352 only one or two n-alkanes. Between the consecutive normal alkanes are a series of 

353 primarily isoalkane isomers which are present in consistent patterns. 

354 9.7.2.2. Cycloalkanes—Between the consecutive normal alkanes are a series of 

355 cycloalkane isomers which are present in consistent patterns based on carbon range and 

356 may be comparable in abundance to the alkane EIP. 

357 (1) Methylcyclohexane is present when n-C7 and n-C8 are present (12)

358 9.7.2.3. Alkylbenzenes—When present, they are in the diagnostic pattern associated with 

359 their carbon range: 

360 (1) Toluene, if range encompasses n-C7-n-C8.

361 (2) Three peak C2- alkylbenzenes, if the range encompasses n-C8-n-C9.

362 Key Diagnostic Features (KDF) of Medium Petroleum Distillates (MPD)

363 9.8. The bulk of the chromatographic pattern occurs in the range of n-C8 to n-C13 and encompasses 

364 two to four normal alkanes.

365 9.9. TIC—With the exception of minor aromatic contributions, the chromatographic patterns for all 

366 MPDs that elute in a given carbon range are consistent. 

367 9.9.1. The pattern is dominated by a Gaussian distribution of peaks with a homologous series of 

368 spiking normal alkanes. 

369 9.9.2. A series of isoalkanes and cycloalkane isomers are between the consecutive n-alkanes. 

370 The chromatographic pattern of these less abundant alkane and cycloalkane peaks is 

371 consistent among all distillates (refer to appendix X1.3). Due to the number of isoalkanes 

372 and cycloalkane isomers present, these compounds can appear unresolved. 

373 9.9.3. Aromatic compounds (alkylbenzenes, indanes, polynuclear aromatics) can be present but 

374 may not be of sufficient abundance to be visualized on the TIC. The abundance varies 

375 between formulations.

376 9.10. EIP—The alkane profile is more abundant than alkylbenzene, cycloalkane, indane, and 

377 polynuclear aromatic profiles. 
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378 9.10.1. Alkanes—The pattern in dominated by a Gaussian distribution of peaks with a 

379 homologous series of spiking normal alkanes.

380 9.10.1.1. Between the consecutive normal alkanes are a Gaussian distribution of isoalkane 

381 isomers which are present in consistent patterns.

382 9.10.2. Cycloalkanes—A Gaussian distribution of cycloalkane isomers in a generally unresolved

383 pattern.

384 9.10.2.1. Trans-decalin.

385 9.10.3. Alkylbenzenes—When these compounds are present, they are in the diagnostic pattern 

386 associated with their carbon range: 

387 9.10.3.1. Toluene, if range encompasses n-C7-n-C8.

388 9.10.3.2. Three peak C2- alkylbenzenes, if the range encompasses n-C8-n-C9.

389 9.10.3.3. Five peak C3- alkylbenzene group, if the range encompasses n-C9-n-C10.

390 9.10.3.4. 1,2,4-TMB and 1,2,3-TMB, if the range encompasses n-C9-n-C10.

391 9.10.3.5. C4- alkylbenzene groups, if the range encompasses n-C10-n-C11.

392 9.10.4. Indanes—When these compounds are present, indane, the C1-indane group, and the C2-

393 indane group are present in the range of n-C10-n-C12. 

394 9.10.5. PNAs—When these compounds are present, naphthalene and the C1-PNA group are 

395 present in the range of n-C11-n-C13. 

396 Key Diagnostic Features (KDF) of Heavy Petroleum Distillates (HPD)

397 9.11. TIC—With the exception of minor aromatic contributions, the chromatographic patterns 

398 for all HPDs that elute in a given boiling point (n-alkane) range are consistent. 

399 9.11.1. The pattern is dominated by a Gaussian distribution of peaks with a homologous series of 

400 spiking normal alkanes. These products generally contain a minimum of five consecutive 

401 normal alkanes; however, it also includes a subclass of narrow ranged distillates starting 

402 above n-C11 which encompass fewer than five n-alkanes. 

403 9.11.2. A series of isoalkanes and cycloalkane isomers are between the consecutive n-alkanes. 

404 The chromatographic pattern of these less abundant alkane and cycloalkane peaks is 

405 generally consistent among all distillates (refer to appendix X1.4). Due to the number of 

406 isoalkanes and cycloalkane isomers present, these compounds can appear unresolved. 

407 9.11.3. Aromatic compounds (alkylbenzenes, indanes, polynuclear aromatics) can be present but 

408 may not be of sufficient abundance to be visualized on the TIC. The abundance varies 

409 between formulations. 

410 9.12. EIP—The alkane profile is more abundant than alkylbenzene, cycloalkane, indane, and 

411 polynuclear aromatic profiles. 

412 9.12.1. Alkanes—The pattern is dominated by a Gaussian distribution of peaks with a 

413 homologous series of spiking normal alkanes. Between the consecutive normal alkanes is a 

414 Gaussian distribution of isoalkane isomers which are present in consistent patterns. 

415 9.12.1.1. Pristane is present following n-C17, and phytane is present following n-C18 if the 

416 boiling point range includes n-C17 or n-C18, respectively. 
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417 9.12.2. Cycloalkanes—A Gaussian distribution of cycloalkanes in a generally unresolved pattern.

418 9.12.2.1. Trans-decalin, if the range encompasses n-C10. 

419 9.12.3. Alkylbenzenes—When present, they are in the diagnostic pattern associated with their 

420 carbon range: 

421 9.12.3.1. Five peak C3-alkylbenzene group, in the range of n-C9-nC10.

422 9.12.3.2. 1,2,4-TMB and 1,2,3-TMB, if the range encompasses n-C9-n-C10.

423 9.12.3.3. C4-alkylbenzene groups, in the range of n-C10-n-C11. 

424 9.12.4. Indanes—Indane, the C1-indane group, and the C2-indane group are present in the range 

425 of n-C10-n-C12. 

426 9.12.5. PNAs—Naphthalene, C1- PNA, and C2- PNA groups are present in the range of n-C11-n427 C15. 

428 10. Key Diagnostic Features of Isoparaffinic Products

429 10.1. Isoparaffinic products are comprised almost exclusively of branched chain aliphatic 

430 compounds (isoalkanes). Isoparaffinic products are the result of refinery processes, including 

431 alkylation and isomerization, to isolate or create isoalkanes in targeted carbon ranges. The 

432 carbon range is dependent upon the specific formulation. Aromatics (alkylbenzenes, indane, 

433 and polynuclear), n-alkanes, and cycloalkanes have been removed or transformed to 

434 isoalkanes from the crude oil distillate fraction from which the product was derived. As a 

435 result, n-alkanes, cycloalkanes or aromatic compounds are not present.

436 10.2. TIC—Isoparaffinic products are composed of branched alkanes. The number of isomers 

437 increases as the molecular size increases. Generally, this results in patterns composed of fewer 

438 compounds in the lower carbon ranges and more complex patterns at higher carbon ranges. 

439 Consistent compounds are present throughout the light, medium and heavy ranges of 

440 isoparaffinic products (as applicable), but in ratios that are representative of the subclass. 

441 10.2.1. LIPs are not as commercially prevalent as MIPs. The LIPs are generally composed of 

442 three to five predominant branched alkanes and additional lower abundant isomers. 

443 10.2.2. In MIPs the TICs are generally composed of more than five predominant branched 

444 alkanes with minor abundance branched alkanes. The MIPs are generally encompassing a

445 carbon range of no more than 4 n-alkanes. 

446 10.2.3. HIPs are not as commercially prevalent as the MIPs. They are composed of numerous 

447 isoparaffinic isomers in a high carbon range which results in patterns of low resolution 

448 with few distinct chromatographic features consisting of unidentifiable branched alkanes. 

449 10.3. EIP: 

450 10.3.1. Alkanes—Most abundant profile; pattern resembles the TIC (refer to appendix X1.5). 

451 10.3.1.1. LIPs—The alkane profile may be composed of a few highly volatile compounds or 

452 some highly volatile compounds with some less volatile compounds nearing the 

453 medium range. The highly volatile compounds may be encountered in liquid 

454 samples but are unlikely to be encountered in debris samples exposed to fire or 

455 other environmental conditions. 

456 10.3.1.2. MIPs—The alkane profile shows distinct patterns of interest. C10, C11, and C12
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457 isomers are prevalent. The relative ratios of these to each other change vary 

458 depending on the formulation as related to the carbon range of the product. 

459 10.3.1.3. HIPs—The alkane profile generally shows a pattern of low resolution with few 

460 distinct chromatographic features. The alkane profile is the most abundant profile. 

461 10.3.2. Cycloalkanes—The mass spectra for isoalkanes contain ions which comprise the 

462 cycloalkane profile. As a result, cycloalkane profile will generally resemble the alkanes 

463 profile in a lower abundance. 

464 10.3.3. Alkylbenzene—Not present.

465 10.3.4. Indanes—Not present. 

466 10.3.5. PNAs—Not present.

467 11. Key Diagnostic Features of Naphthenic-Paraffinic Products

468 11.1. Naphthenic-paraffinic products are derived from distillates in which the aromatic compounds, 

469 and to an extent n-alkane compounds, are removed. As a result, the aromatic compounds 

470 including alkylbenzenes, indane, PNAs, or a combination thereof, are not present and the n471 alkane compounds have been removed or reduced. The carbon range and pattern are 

472 dependent on the specific formulation. Light naphthenic-paraffinic products are uncommon. 

473 11.2. TIC—Pattern comprised mostly of cycloalkanes (naphthenic) and isoalkanes (isoparaffinic). 

474 n-alkanes, when present, are in reduced amounts compared to that in a distillate. 

475 11.3. EIP—Alkane and Cycloalkane profiles are the most abundant (refer to appendix X1.6). 

476 Alkylbenzene, Indane, and PNA profiles are not present. 

477 11.3.1. Alkanes—Pattern consists almost exclusively of branched alkanes. Isoalkane peaks are 

478 present and their abundance is comparable to cycloalkane peaks. In medium or heavy 

479 products, if the major n-alkane peak is present at greater than 1.5 times the major 

480 isoalkane or cycloalkane peak(s) with comparable carbon range, then the product is 

481 classified as a distillate rather than a naphthenic-paraffinic product (12).

482 11.3.2. Cycloalkanes—Pattern consists of groups of cycloalkane or isoalkane compounds in 

483 between the spiking n-alkanes. Cycloalkanes are comparable in abundance to isoalkanes. 

484 Spiking n-cycloalkanes are more obvious in summed EIP of heavy naphthenic-paraffinic 

485 products and in single ion (83) EIP. Pattern comparable to known naphthenic-paraffinic 

486 products. 

487 11.3.3. Alkylbenzenes—Not present.

488 11.3.4. Indanes—Not present. 

489 11.3.5. PNAs—Not present. 

490 12. Key Diagnostic Features of Aromatic Products

491 12.1. Aromatic products are comprised almost exclusively of alkylbenzene compounds, indanes, 

492 polynuclear aromatic compounds, or a combination thereof; alkanes and cycloalkanes are not 

493 present. The boiling point range and pattern are dependent on the specific formulation. 

494 Aromatic products are the result of refinery processes, including reforming, to isolate or 

495 create aromatic compounds in targeted carbon ranges. Unlike gasoline, aromatic products 

496 generally are narrow range products, but a few may contain a larger range. 
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497 12.2. TIC:

498 12.2.1. LAPs typically consist of toluene, C2-alkylbenzenes, or both. 

499 12.2.2. MAPs usually consist of C3-, C4-alkylbenzenes, C1-, C2-indanes but the composition 

500 depends on the formulation. The TIC will resemble that of gasoline within the product 

501 range. 

502 12.2.3. HAPs consist mostly of polynuclear aromatics. 

503 12.3. EIP—Aromatic ion profiles (either alkylbenzene or polynuclear aromatic) are the most 

504 abundant profiles and resembles the TIC (refer to appendix X1.7 through X1.9). 

505 12.3.1. Alkanes—Not present. 

506 12.3.2. Cycloalkanes—Not present. 

507 12.3.3. Alkylbenzenes—Most abundant profile in LAPs and MAPs. Pattern depends on 

508 formulation; however, it will resemble the TIC.

509 12.3.4. Indanes—C1-, C2-indanes are present in aromatic products that encompass n-C11-n-C12.

510 12.3.5. PNAs—Most abundant profile in HAPs. Naphthalene as well as C1- and C2-PNAs may be 

511 present in HAPs if the pattern encompasses n-C11-n-C15. PNA pattern depends on 

512 formulation.

513 13. Key Diagnostic Features of Normal Alkane Products

514 13.1. Normal alkane products are produced by physical separation (molecular sieve) from 

515 petroleum feedstocks. They typically have very narrow boiling point ranges and consist of 

516 three to seven n-alkanes. Isoalkanes, cycloalkanes, or aromatics (alkylbenzenes, indanes, 

517 polynuclear) are not present in these products. 

518 13.2. TIC—Comprised almost exclusively of n-alkanes in a homologous series (refer to appendix 

519 X1.10).

520 13.2.1. The carbon range and pattern are dependent on the specific formulation.

521 13.3. EIP—The only diagnostic profile is the alkane profile. Cycloalkane, alkylbenzene, indane and 

522 PNAs compounds are not present.

523 13.3.1. Alkanes—A narrow carbon range of homologous n-alkanes are present. Isoalkanes are 

524 not present. 

525 14. Key Diagnostic Features of Oxygenated Solvents

526 14.1. Oxygenated ignitable liquids are most commonly comprised of very low boiling compounds. 

527 The most common examples are alcohols (ethanol, isopropyl alcohol), esters, and ketones 

528 (methyl ethyl ketone, methyl isobutyl ketone). 

529 14.2. TIC—Products comprised exclusively of oxygenated peaks (refer to appendix X1.11). 

530 14.2.1. The mere presence of oxygenated compounds, such as alcohols or acetone, does not 

531 indicate that a foreign ignitable liquid is present in the sample. A large excess of the 

532 compound (at least one order of magnitude above the matrix peaks in the 

533 chromatogram) should be present before classifying an oxygenated compound. 

534 14.2.2. This class does not include oil and fat-based products. 
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535 14.3. EIP—Alkanes, cycloalkanes, alkylbenzenes, indanes, and PNAs are not present. 

536 15. Key Diagnostic Features of Petroleum Products

537 15.1. This class describes products that have a singular distinct carbon range and are primarily 

538 consistent with one of the previously mentioned classifications; however, they do not meet the 

539 criteria for a single classification or a mixture (refer to appendix X1.12), such as: 

540 15.1.1. Enhanced aromatics in a distillate.

541 15.1.2. Distillate present in a primarily aromatic pattern. 

542 15.1.3. HPD which includes n-C17 and n-C18 but does not contain pristane or phytane.

543 15.2. TIC—The chromatographic patterns for petroleum products will vary and will meet 

544 requirements from more than one class. 

545 15.2.1. Petroleum products will have characteristics of more than one class but will not have 

546 sufficient characteristics to identify two or more separate classes within the same carbon 

547 range. 

548 NOTE 7—If the TIC and EIPs contain the requirements to classify more than one pattern, 

549 then classify each pattern separately. Refer to Section 17 for additional guidance. 

550 15.2.2. The carbon range and pattern are dependent on the specific formulation.

551 15.3. EIP—The profiles will be dependent on the observed pattern(s).

552 15.3.1. Alkanes—Pattern dependent. 

553 15.3.2. Cycloalkanes—Pattern dependent. 

554 15.3.3. Alkylbenzenes—Pattern dependent. 

555 15.3.4. Indanes—Pattern dependent. 

556 15.3.5. PNAs—Pattern dependent. 

557 16. Key Diagnostic Features of Oil and Fat-Based Products (13, 14, 15, 16)

558 16.1. Oil and fat-based products cover those composed of fatty acids, FAMEs (fatty acid methyl 

559 esters), and biofuels. They are refined from plant or animal sources and include pure oils 

560 which have the potential for spontaneous ignition and products made from the 

561 transesterification of fatty acids. 

562 16.1.1. Fatty acids and FAMEs are identified based on their carbon length and the position of 

563 the double bond location. It is not necessary to identify the specific isomer(s) present.

564 16.1.2. Pure oil and fat products are typically derivatized FAMEs for analysis (refer to E2881). 

565 Products containing FAMEs do not need to be derivatized prior to GC-MS analysis.

566 16.1.2.1. In pure oil and fat products, hydrocarbons, including alkanes, isoalkanes, 

567 cycloalkanes, and aromatics (alkylbenzenes, indanes, and PNAs), are absent.

568 16.1.3. Some wood finishes, treatments, sealants, environmentally friendly lighter fluids, and 

569 firelog fuels are mixtures of fatty acids with other ignitable liquid classifications. These 

570 are usually found in proprietary formulations (for example, wood finishes) and can 

571 include the following ignitable liquid classifications: 

572 16.1.3.1. Petroleum distillates.
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573 16.1.3.2. Naphthenic-paraffinic products.

574 16.1.3.3. Aromatic products.

575 16.1.3.4. Transesterified oil and fat-based products (FAMEs).

576 16.1.4. Consider evaluating samples containing other ignitable liquid classifications as well as

577 negative samples for the presence of fatty acids, FAMEs, or a combination of both.

578 16.1.4.1. Caution—The presence of fatty acids does not necessarily indicate that a foreign 

579 oil or fat-based product is present in the sample. Take caution when identifying 

580 fatty acids when only saturated fatty acids are present. 

581 Key Diagnostic Features of Oil and Fat-based

582 16.2. General—This class includes underivatized fatty acids from animal and vegetable 

583 sources, some which have the potential for spontaneous ignition. They typically contain high 

584 levels of polyunsaturated fatty acids and include corn, cottonseed, fish, linseed, perilla, rapeseed, 

585 soybean and tung oils (10). These are typically transesterified during analysis and analyzed as 

586 FAMEs.

587 16.3. TIC—The TIC will be comprised of saturated and unsaturated transesterified fatty acids

588 (refer to appendix X1.13).

589 16.4. EIP—Alkanes, cycloalkanes, alkylbenzenes, indanes and PNAs are not present. 

590 16.4.1. Additional extracted ions can be used to assess the sample’s unsaturation level.

591 16.4.1.1. n-C16:0 – ion 270.

592 16.4.1.2. n-C16:1 – ion 268.

593 16.4.1.3. n-C18:0 – ion 298.

594 16.4.1.4. n-C18:1 – ion 296.

595 16.4.1.5. n-C18:2 – ion 294.

596 16.4.1.6. n-C18:3 – ion 292.

597 Key Diagnostic Features of FAME-Based Products

598 16.5. General—FAME-based products are transesterified prior to commercial distribution and 

599 are comprised of FAMEs. While not always marketed as such, they can be present in 

600 combination with underivitized oils and fats, petroleum products or light oxygenated solvents. 

601 When present in combination with underivatized oils and fats or other ignitable liquid 

602 classifications, refer to Section 17 for additional guidance. 

603 16.6. TIC—The sample will be comprised exclusively of FAMEs derived from vegetable and 

604 animal sources or present as a mixture of FAMEs and different classes. 

605 16.7. EIP—FAMEs present vary based on formulation. 

606 16.7.1. Ion 74 can be used to screen for the presence of FAMEs.

607 Key Diagnostic Features of Biofuels

608 16.8. General— “Biodiesel” refers to engine fuels which are comprised of FAMEs or mixtures 

609 of HPDs and FAMEs (Refer to E2997 and appendix X1.14).
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610 16.9. TIC and EIP—The sample will be comprised exclusively of FAMEs (for example, B100), 

611 or a mixture of FAMEs and distillates (for example, B20).

612 16.9.1. Ions 74 and 294 can be used to screen for the presence of biofuels.

613 16.9.1.1. Mixtures of HPDs and FAMEs may be further sub-classified as “biodiesel.”

614 16.9.1.2. Refer to Section 17 for further guidance on mixtures.

615 17. Key Diagnostic Features of Single Components

616 17.1. Single components are characterized by their retention time and mass spectrum. Refer to 

617 EXXX (Interpretation) for the requirements for identification of single components.

618 18. Key Diagnostic Features of Mixtures

619 18.1. More than one ignitable liquid class or subclass may be present in a single sample (refer to 

620 appendix X1.15).

621 18.1.1. When two or more classes or subclasses are present, the requirements for each class are

622 met. 

623 NOTE 8—Mixtures of ignitable liquid classifications can be the result of a single 

624 commercial product or a mixture of products. This standard cannot differentiate 

625 between ignitable liquids that are mixed by a manufacturer for sale or ignitable liquids 

626 mixed at the point of use. 

627 19. Other Ignitable Liquid Products

628 19.1. No classification system is likely to describe all possible ignitable liquids. Numerous 

629 commercial and industrial products are ignitable and do not fall into any of the above 

630 classifications. Many of these are synthetic mixtures consisting of only a few compounds, rather 

631 than distillation fractions, such as terpenes. For such products, describe the composition instead 

632 of classifying it as a “miscellaneous” or other product. 

633 20. Keywords

634 20.1. FAME, fire debris; forensic sciences; ignitable liquid 

635

636 Appendix

637 (Nonmandatory Information)

638 X1 Classification Examples, Labeled with KDFs

639 X1.1 Table X1.1 displays the key for groupings labeled in images located in the appendix along with 

640 the sections within the standard which reference the groups.

641 X1.2 Table X1.2 displays the key for chemicals labeled in images located in the appendix along with the 

642 sections within the standard which reference the chemicals

643 TABLE X1.1 Table of Groupings

Designation Group Name Cited Sections

A C2-alkylbenzenes 8.2.5.3, 8.3.3.2, 9.7.2.3, 9.10.3.2, 12.2.1
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B C3-alkylbenzenes 8.2.5.4, 8.3.3.3, 9.10.3.3, 12.2.2

C C4-alkylbenzenes, group 1 8.2.5.8, 8.3.3.6, 9.10.3.5, 9.12.3.3, 12.2.2

D C4-alkylbenzenes, group 2 8.2.5.9, 8.3.3.7, 9.10.3.5, 9.12.3.3, 12.2.2

E C4-alkylbenzenes, group 3 8.2.5.10, 8.3.3.8, 9.10.3.5, 9.12.3.3, 12.2.2

F C1-indanes 8.2.5.11, 8.3.4.2, 9.5, 9.10.4, 9.12.4, 12.2.2, 

12.3.4

G C2-indanes 8.3.4.3, 9.5, 9.10.4, 9.12.4, 12.2.2, 12.3.4

H C1-PNAs 8.2.5.13, 8.3.5.2, 9.10.5, 9.12.5, 12.3.5

I C2-PNAs 8.3.5.3, 9.12.5, 12.3.5

J Area of medium isoparaffinic contribution, if present 8.3.1

K C5-alkylbenzenes 8.1, 8.3.3.9

L Isoalkane and cycloalkane isomers 9.1, 9.2, 9.7, 9.7.1, 9.7.1.1, 9.7.2.1, 9.9.2, 

9.10.1.1, 9.10.2, 9.11.2, 9.12.1, 11.3.1, 11.3.2

644

645 TABLE X1.2 Table of Chemicals

Designation Common Name IUPAC Name Cited Sections

1 Isooctane 2,2,4-trimethylpentane 8.2.5.1, 8.3.1.1

2 Trimethylpentane 2,3,4-trimethylpentane 8.2.5.2, 8.3.1.2

3 Methylcyclohexane methylcyclohexane 9.7.1.1, 9.7.2.1.(1)

4 Toluene methylbenzene 8.1, 8.2.5.2, 8.3.3.1, 9.7.2.3, 

9.10.3.1, 12.2.1

5 Ethylbenzene ethylbenzene

6 n-propylbenzene propylbenzene

7 C10 alkane isomer 8.2.5.4, 8.3.1.3

8 1,2,4-TMB 1,2,4-trimethylbenzene 8.2.5.4, 8.2.5.5, 8.3.3.3, 8.3.3.4, 

9.10.3.4, 9.12.3.2

9 Decane Decane 8.3.1.4

10 1,2,3-TMB 1,2,3-trimethylbenzene 8.2.5.6, 8.3.3.5, 9.10.3.4, 9.12.3.2

11 Indane 2,3-dihydro-1H-indene 8.2.5.7, 8.3.4.1, 9.5, 9.10.4, 9.12.4

12 trans-decalin trans-Decahydronaphthalene 9.10.2.1, 9.12.2.1

13 Naphthalene bicyclo[4,4,0]deca-1,3,5,7,9-pentane 8.2.5.12, 8.3.3.9, 8.3.5.1, 9.10.5, 

9.12.5, 12.3.5

14 Pristane 2,6,10,14-tetramethylpentadecane 9.12.1.1, 15.1.3

15 Phytane 2,6,10,14-tetramethylhexadecane 9.12.1.1, 15.1.3

16 Ethanol ethyl alcohol 8.1.1, 8.2.3.1, 8.2.4, 14.1

17 MTBE 2-methoxy-2-methylpropane 8.2.4
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

23

646

647 Fig. X1.1 Gasoline

648
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

24

649
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

25

650 Fig. X1.2 LPD

651

652

653 Fig. X1.3 MPD
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

26

654
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

27

655 Fig. X1.4 HPD

656
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

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657 Fig. X1.5 Isoparaffinic Product

658

659 Fig. X1.6 Naphthenic-Paraffinic Product
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

29

660

661 Fig. X1.7 LAP
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

30

662

663 Fig. X1.8 MAP
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

31

664
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

32

665 Fig. X1.9 HAP

666

667 Fig. X1.10 Normal Alkanes Product
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

33

668

669

670

671

672

673

674

675

676

677

678

679

680
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

34

681 Fig. X1.11 Oxygenated Product

682
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

35

683 Fig. X1.12 Petroleum Product

684 This product shows elevated aromatics in an overlapping pattern with an MPD and is classified as a 

685 medium petroleum product. 

686
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

36

687 Fig. X1.13 Oil and Fat-based Product

688
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

37

689 Fig. X1.14 Biodiesel

690
OSAC 2022-S-0004 Standard Classification for 

Ignitable Liquids Encountered in Fire Debris Analysis

38

691 Fig. XI.15 Mixture of an MPD and Aromatic Product

692 This data shows an aromatic product whose pattern is separated from the majority of the chemicals in the 

693 MPD and is classified as a mixture of a light aromatic and a medium petroleum distillate. 

694

695

696 REFERENCES
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Ignitable Liquids Encountered in Fire Debris Analysis

39

697 1. National Center for Forensic Science – Ignitable Liquids Reference Database. Available at: 

698 http://ilrc.ucf.edu

699 2. Stauffer, E.; Dolan, J. A.; and Newman, R., Fire Debris Analysis, Academic Press, Elsevier, MA, 2008.

700 3. Gilbert, M. W., “The Use of Individual Extracted Ion Profiles Versus Summed Extracted Ion Profiles in 

701 Fire Debris Analysis,” Journal of Forensic Sciences, Vol 43, No. 4, 1998, pp. 871-876.

702 4. Smith, R. M., “Arson Analysis by Mass Chromatography,” Analytical Chemistry, Vol 54, 1982, pp. 

703 1399A–1409A.

704 5. Kelly, R. L., and Martz. R. M., “Accelerant Identification in Fire Debris by Gas Chromatography/Mass 

705 Spectrometry Techniques.” Journal of Forensic Sciences, Vol 29, No. 3, 1984, pp. 714-722.

706 6. Keto, R. O., “GC ⁄ MS Data Interpretation for Petroleum Distillate Identification in Contaminated Arson 

707 Debris,” Journal of Forensic Sciences, Vol 40, No. 3, 1995, pp. 412-423.

708 7. Hendrikse, J., Grutters, M., and Schäfer, F., Identifying Ignitable Liquids in Fire Debris, 1st ed., Academic 

709 Press, Elsevier, London, 2015.

710 8. Keto, R.O., and Wineman, P.L., “Detection of Petroleum-Based Accelerants in Fire Debris by Target 

711 Compound Gas Chromatography/Mass Spectrometry”, Analytical Chemistry, Vol 63, No. 18, September 

712 15, 1991, pp. 1964–1971.

713 9. McLafferty, F.W., and Turecek, F., Interpretation of Mass Spectra, 4th Edition, University Science Books, 

714 Sausalito, California, 1993, pp. 233 and 247.

715 10. Evans-Nguyen, K., Hutches, K. (2019). Forensic Analysis of Fire Debris and Explosives. Springer Nature 

716 Switzerland.

717 11. L.J., Grutters, M.M.P, Hendrikse, J. N., Alkylate Components for Classifying Gasoline, J Forensic Sci, 

718 March 2018, Vol. 63, No. 2, doi: 10.1111/1556-4029.13563.

719 12. Antos, G.J.; Aitani, A.M., Catalytic Naphtha Reforming, Second Edition, Revised and Expanded, Marcel 

720 Dekker, Inc. New York, NY, 2004.

721 13. Stauffer, E.; Byron, D., Alternative fuels in Fire Debris Analysis: Biodiesel Basics, J Forensic Sci, March 

722 2007, Vol. 52, No. 2, doi:10.1111/j.1556-4029.2006.00380.x

723 14. Gambrel, A.K.; Reardon, M.R., Extraction, Derivatization, and Analysis of Vegetable Oils from Fire 

724 Debris, J Forensic Sci, November 2008, Vol. 53, No. 6, doi: 10.1111/j.1556-4029.2008.00882.x

725 15. Goodman, M.R., Kaley, E.A., Finney, E.E., Forensic analysis of biodiesel, Forensic Science International, 

726 263 (2016) 10-26

727 16. Stauffer, E., A Review of the Analysis of Vegetable Oil Residues from Fire Debris Samples: Spontaneous 

728 Ignition, Vegetable Oils, and the Forensic Approach, J Forensic Sci, Sept. 2005, Vol. 50, No. 5, Paper ID 

729 JFS2004510

730 17. Hetzel, S., Survey of American (USA) Gasolines (2008), J Forensic Sci, January 2015, Vol. 60, No. S1, 

731 doi: 10.1111/1556-4029.12595

732 18. Christy, B., Winters, K., Rossheim, A., Newman, R., Tang, L. A foundational study of fire debris 

733 interpretation using quantitative measures of chromatographic features in gasoline and the use of graphical 

734 display to demonstrate data sufficiency. Forensic Chemistry, March 2021, Volume 24, 

735 https://doi.org/10.1016/j.forc.2021.100337