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Proficiency Testing in Ignitable Liquid Residue Analysis

Technical/Scientific Working Group for Fire and Explosions Analysis (T/SWGFEX) Position

Laboratory Fire Standard Protocols Committee - April 2015

Dale C. Mann,a

B.S; Mike A. Trimpe,b M.A.; Andrew T. Armstrong,c Ph.D; James C. Vose,dB.A.; Philip

R. Antoci,e M.S.; P. Mark L. Sandercock.f Ph.D.

Proficiency testing is a vital component of proper quality control in forensic science. Proficiency samples 

for fire debris analysis in particular have proven to be problematic. Therefore, there is a need for 

consistent and reliable proficiency testing. The intent of this position paper is to provide guidance and 

technical advice concerning fire debris analysis proficiency testing in order to improve the reliability of 

the recovery, analysis, and interpretation of results to meet the needs of the forensic laboratory 

community.

In light of the National Academy of Sciences report,1 laboratory accreditation requirements,2,3 court 

scrutiny of forensic science practice,4,5,6,7 and the fundamental need for accurate test results and to 

demonstrate competency, the importance of a properly designed proficiency test cannot be 

underestimated. Recognized organizations have guidelines that should be followed when creating 

proficiency tests.8, 9, 10

The inconsistency of recent fire debris/ignitable liquid proficiency test results have highlighted the need 

for proficiency test providers to be more attuned to the needs of the forensic community. Specifically, fire 

debris proficiency tests should address the following criteria.11

• Test the ability to recover, analyze, and/or interpret gas chromatograph – mass spectrometer data 

for the presence of ignitable liquid residues (ILR). Tests may be designed such that the emphasis 

of an individual test may focus on the proficiency to prepare, recover, analyze, and/or interpret 

the analytical data.

• Accurate test results should be attainable using accepted methods (e.g. ASTM consensus

documents).12,13,14,15,16

• The testing should be conducted in the same manner as casework.

___________________________

This Position Paper has been complied with the valuable contributions of the members of the Technical/Scientific Working 

Group for Fire and Explosions Analysis (T/SWGFEX) Laboratory Fire Standard Protocols Committee and the T/SWGFEX

Executive Committee. The Mission of the Fire Standard Protocols Committee is “To advance the practices of forensic 

laboratories in the examination and analysis of evidentiary samples associated with fire investigations.” 

Author Affiliations:

a MDE Forensic Engineering and Laboratories, Inc., 700 South Industrial Way, Seattle, WA 98108 b Hamilton County Coroner’s Office /Crime Laboratory, 3159 Eden Avenue, Cincinnati, OH 45219 c Armstrong Forensic Laboratory, Inc., 330 Loch'n Green Trail, Arlington, TX 76012 d Chemistry Unit, Vermont Forensic Laboratory, Department of Public Safety, Division of Criminal Justice

 Services, 103 South Main Street, Waterbury, VT 05671-2101 e Co-chair T/SWGFEX Laboratory Fire Standard Protocols Committee. New York Police Department Police

Laboratory, 150-14 Jamaica Ave, Jamaica, NY 11432 f Co-chair T/SWGFEX Laboratory Fire Standard Protocols Committee. Trace Evidence Services, Royal Canadian

 Mounted Police, 15707-118 Avenue, Edmonton, AB T5V 1B7, Canada
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• Test samples should be representative of those routinely encountered in casework, for example, 

burned and unburned matrix with and without ILR. Matrices may include those commonly 

encountered at a fire scene (e.g. wood, carpet, tile, fabric, shoes, and plastics). Matrix samples 

must be extensively characterized in the unburned and burned state prior to use in a test sample. 

ILR interactions including interferences as a result of contact with the matrix must be 

documented prior to the distribution of test samples.

• Each test should include a comparison matrix sample with the test samples.

• The types of ignitable liquids used in tests should be readily available and commonly encountered

in casework such as found in the Ignitable Liquid Reference Collection (ILRC).17 Ignitable 

liquids selected as test samples must be analyzed and classified with unequivocal consensus 

between at least two referee laboratories or directly comparable to an ignitable liquid in the 

ILRC.

• Tests should use products in various stages of evaporation.

• The test should measure the ability of the analyst to identify ILR patterns in the presence of

combustion and pyrolysis components, and to classify the ILR according to the current ASTM 

E1618 classification scheme.16

• Prior to distribution, sample sets must be tested by at least two referee laboratories to verify that 

consistent and expected results can be obtained. Any inconsistencies must be addressed prior to 

the distribution of test samples.

• After distribution, and upon collection and compilation of proficiency test results, the test 

provider must publish participant test methods and results. Details on preparation of the test 

samples, as well as referee laboratory methods and test results must also be included.

• Test results should be provided to the laboratory examiners who participated in the test.

Following the publication of a test provider`s results, it is the responsibility of the forensic science

community to evaluate the summarized test results and to annually publish the evaluation. Through the

collaborative effort of forensic science practitioners, accrediting agencies, and the proficiency test

providers, the quality of forensic services will be improved.

___________________________

References

1. Strengthening Forensic Science in the United States: A Path Forward, National Academy of 

Sciences, 2009.

2. International Organization for Standardization. ISO/IEC 17025 General requirements for the 

competence of testing and calibration laboratories, 2005.

3. American Society of Crime Laboratory Directors Laboratory Accreditation Board (ASCLD/LAB) 

Proficiency Testing and Review Program. Effective date July 22, 2014; AL-PD-1020-Ver 1.1. 

and ASCLD/LAB – International Supplemental Requirements for the Accreditation of Forensic 

Science Testing Laboratories 2011 Edition; Section 5.9.3. These documents conform to ISO/IEC 

17025:2005. Information is available at www.ascld-lab.org

4. Saks MJ. Implications of the Daubert test for forensic identification science. Shepard’s Expert 

and Science Evidence Quarterly, 1994; 1(3): 427-434.

5. Saks MJ, Faigman DL. Fail forensics: how forensic science lost its way and how it might yet find 

it. Annual Review of Law and Social Science, 2008; 4:149-171.
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6. Evett IW. Expert evidence and forensic misconceptions of the nature of exact science. Science &

Justice, 1996; 36(2): 118-122.

7. Cole SA. Forensics without uniqueness, conclusions without individualization: the new 

epistemology of forensic identification. Law, Probability & Risk, 2009; 8(3): 233-255.

8. Scientific Working Group for Materials Analysis (SWGMAT). Trace evidence proficiency 

testing guidelines. Forensic Science Communications, 2001; 3(3).

9. ASTM International. ASTM E1301-95(2003) Standard Guide for Proficiency Testing by 

Interlaboratory Comparisons. ASTM International, West Conshohocken, PA, USA; 2003 

(withdrawn, July 2012, in accordance with section 10.5.3.1 of the Regulations Governing ASTM 

Technical Committees, which requires that standards shall be updated by the end of the eighth 

year since the last approval date).

10. International Organization for Standardization. ISO/IEC 17043:2010 Conformity assessment –

General Requirements for Proficiency Testing, 2010.

11. Fultz M, Culver J. Analysis protocols and proficiency testing in fire debris analysis. Proceedings 

of the International Symposium on the Forensic Aspects of Arson Investigations. George Mason 

University, Fairfax, Virginia, USA: Federal Bureau of Investigation; 1995. p. 165-193.

12. ASTM International. ASTM E1388-12 Standard Practice for Sampling of Headspace Vapors 

from Fire Debris Samples. ASTM International, West Conshohocken, PA, USA; 2012.

13. ASTM International. ASTM E1412-12 Standard Practice for Separation of Ignitable Liquid 

Residues from Fire Debris Samples by Passive Headspace Concentration With Activated 

Charcoal. ASTM International, West Conshohocken, PA, USA; 2012.

14. ASTM International. ASTM E1413-13 Standard Practice for Separation and Concentration of 

Ignitable Liquid Residues from Fire Debris Samples by Dynamic Headspace Concentration. 

ASTM International, West Conshohocken, PA, USA; 2013.

15. ASTM International. ASTM E1386-10 Standard Practice for Separation and Concentration of 

Ignitable Liquid Residues from Fire Debris Samples by Solvent Extraction. ASTM International, 

West Conshohocken, PA, USA; 2010.

16. ASTM International. ASTM E1618-14 Standard Test Method for Ignitable Liquid Residues in 

Extracts from Fire Debris Samples by Gas Chromatography-Mass Spectrometry. ASTM 

International, West Conshohocken, PA, USA; 2014.

17. Allen SP, Williams MR, Bryant C, Byron D, Cerven J, Cooper BD, Hilliard DC, Hoffmann J, 

Kwast J, Thomas SA, Whitcomb CM. The National Center for Forensic Science Ignitable Liquids 

Reference Collection and database. Forensic Science Communications, 2006; 8(2). Database 

access is available at http://ilrc.ucf.edu/