OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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OSAC 2021-N-0009 

Standard Practice for the 

Collection and 

Preservation of Organic 

Gunshot Residue

Ignitable Liquids, Explosive and Gunshot Residue Subcommittee 

Chemistry: Trace Evidence Scientific Area Committee 

Organization of Scientific Area Committees (OSAC) for Forensic Science 
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

2

2021-N-0009 OSAC Proposed Standard

Standard Practice for the 

Collection and Preservation of 

Organic Gunshot Residue

Prepared by 

Ignitable Liquids, Explosives, and Gunshot Residue Subcommittee

Version: 2.0

November 2021

Disclaimer:

This OSAC Proposed Standard was written by the Ignitable Liquids, Explosive and Gunshot 

Residue Subcommittee of the Organization of Scientific Area Committees (OSAC) for Forensic 

Science following a process that includes an open comment period. This OSAC Proposed 

Standard will be submitted to a standards developing organization (SDO) 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 forensic-science 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.
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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Standard Practice for the Collection and Preservation of Organic Gunshot Residue

1. Scope

1.1. This practice describes procedures for the sampling and preservation of organic gunshot

residues (OGSR) recovered from hands, skin, clothing, and other substrates. This 

standard practice does not apply to the analysis or interpretation of OGSR, or inorganic 

gunshot residue (IGSR).

1.2. This practice is intended for use by competent forensic science practitioners with the 

requisite formal education, discipline-specific training (see Practice E2917), and 

demonstrated proficiency to perform forensic casework.

1.3. This practice does not purport to address all of the possible safety concerns, if any, 

associated with its use. It is the responsibility of the user of this standard to establish 

appropriate safety, health, and environmental practices and determine the applicability of 

regulatory requirements prior to use. 

2. Referenced Documents

2.1. ASTM Standards:

E1492 Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence 

in a Forensic Science Laboratory

E1588 Standard Practice for Gunshot Residue Analysis by Scanning Electron 

Microscopy/Energy Dispersive X-Ray Spectrometry.

E1732 Standard Terminology Relating to Forensic Science

E2917 Standard Practice for Forensic Science Practitioner Training, Continuing 

Education, and Professional Development Programs.

E2998 Standard Practice for Characterization and Classification of Smokeless Powders.

E2999 Standard Test Method for Analysis of Organic Compounds in Smokeless Powder 

by Gas Chromatography-Mass Spectrometry and Fourier Transform Infrared 

Spectroscopy

E3255 Standard Practice for Quality Assurance of Forensic Science Service Providers 

Performing Forensic Chemical Analysis

WK56998 Standard Terminology Relating to the Examination of Explosives.

WK----- Standard Practice for the Collection of Primer Gunshot Residue (pGSR) 

Particles from Clothing, Vehicles, and Other Objects using Adhesive Lifts.

3. Terminology

3.1. Definitions – For definitions of terms that can assist in interpreting this standard, refer to

Terminology E1732 and WK 56998.

3.2. Definitions of terms specific to this standard
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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3.2.1. Inorganic GSR (IGSR), n – Residues from the primer, cartridge case, projectile 

(e.g., bullet or shot pellets), and/or the firearm that are primarily made of metal, 

metal oxides, or metal salts.

3.2.2. Organic GSR (OGSR), n – Residues from the propellant and the priming mixture 

that are organic compounds.

3.2.3. Primer GSR (pGSR), n –Residues generating from the priming mixture that could 

be inorganic or organic in nature.

3.2.4. Stubbing, v – Act of pressing adhesive tape onto a surface to be sampled using a 

collection stub; synonymous with dabbing or tape lifting.

4. Significance and Use

4.1. The most common reason that gunshot residue (GSR) examination is performed is to

determine if an individual was exposed to firearm discharge. Traditional GSR analysis has 

relied upon the detection of inorganic GSR primarily originating from the ammunition 

primer (pGSR) as described in Practice E1588; however, OGSR provides information that 

complements pGSR analysis [1]. This standard practice is of use to forensic laboratories 

desiring to supplement pGSR analysis with OGSR analysis to identify surfaces exposed 

to gunshot residue. 

4.2. OGSR originates from the combustion of the smokeless powder and the priming mixture 

following their ignition during the firearm discharge process. After a firearm has been 

discharged, the combined residue can be found on exposed surfaces in the vicinity of the 

fired weapon (e.g., hands, other exposed skin surfaces, hair, clothing, and other 

surfaces). OGSR can also be found in the cartridge case after firing and can be 

recovered to provide information about the constituents of the propellant or the priming 

mixture, or both. 

4.3. This practice provides guidance on best practices to be followed in the collection and 

preservation of OGSR samples intended for forensic analysis. 

4.4. This practice does not apply to the analysis of intact smokeless powder grains. Refer to 

Practice E2998 and Test Method E2999 for the characterization of intact smokeless 

powder grains. 

5. Materials

5.1. Purity of Reagents – Gas chromatography-mass spectrometry (GC-MS) grade, liquid

chromatography-mass spectrometry (LC-MS) grade, or higher-grade chemicals shall be 

used in the collection of OGSR. Unless otherwise indicated, it is intended that all reagents 

conform to the specifications of the Committee on Analytical Reagents of the American 

Chemical Society, where such specifications are available [1]. Other grades can be used 

if the reagent is of sufficiently high purity to permit its use without lessening the accuracy 

of the determination. 

5.2. Sample Collection Solvents – Acetone, acetonitrile, ethanol, isopropanol, methanol or 

other appropriate solvents.

5.3. Sample Storage Containers – Containers for storing the collection media shall be airtight 

in order to reduce the loss of sample due to evaporation. 
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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5.4. Adhesive Tape Lifts – Suitable adhesive tapes include those used for scanning electron 

microscope (SEM) sample stubs. Other adhesive tapes can be used at the discretion of the 

laboratory [2,3].

5.5. Swabs – Suitable swabs include cotton, polyester, muslin, and nylon-based substrates 

[1,4,5].

5.6. Vacuums – A suitable vacuum shall be fitted with an inert filter membrane, such as 

polytetrafluoroethylene (PTFE) and fiberglass filters, with a maximum porosity of 0.5 μm 

to trap particles, [1,6].

6. Procedure

6.1. Refer to WK_____ for guidelines on minimizing potential contamination of samples

during the collection process.

6.2. There are three commonly accepted sampling techniques for OGSR: adhesive tape 

lifting, swabbing, and vacuuming. Each technique differs in its collection efficacy [4]. 

Consider the surface to be sampled when choosing a sampling technique. 

6.2.1. Adhesive tape lifting can be used to sample from many dry surfaces, including 

skin and clothing.

6.2.2. Swabbing can be used to sample from skin surfaces (e.g., hands, face, neck) or 

inanimate objects (e.g., tables, vehicles, clothing). This technique is appropriate 

for either wet or dry surfaces.

6.2.3. Vacuuming can be used to sample textile objects (e.g., clothing, carpeting, etc.).

6.3. Use a separate sampling device for each surface (e.g., one for the left hand and a 

separate device for the right hand) to maximize sample recovery and avoid cross-surface 

sample commingling, if desired [4,6].

6.4. Adhesive tape lifts

6.4.1. Adhesive tape lifts used for SEM sample stubs effectively collect OGSR from 

many surfaces, including skin, clothing, and objects. Other adhesive tapes can be 

used at the discretion of the individual laboratory. 

6.4.2. Dab the adhesive surface portion of the stub onto the surface to be sampled until 

tackiness is lost to achieve maximum collection efficiency [7].

6.5. Swabbing

6.5.1. Use wet swabs to collect samples from the surface of interest. 

6.5.1.1. Suitable solvents can be found in 5.2. 

Note (1): Ethanol and isopropanol are preferred.

Note (2): Acetone and acetonitrile are not recommended for extended contact 

with skin.

Note (3): Certain solvents can dissolve other compounds in the swab material 

that could interfere with the analysis [4,5,6].

6.5.1.2. Wet substrates should be air-dried prior to sampling with a wet swab.

6.5.2. If a surface is also to be stubbed for recovery of IGSR, perform the adhesive tape 

stubbing first and then swab the sample to collect OGSR residue [4].

6.6. Vacuuming
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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6.6.1. Prior to vacuuming the textile sample, dab the adhesive on the sample using the 

procedure in section 6.3.1 to collect IGSR [8].

6.6.2. Vacuum the area of interest thoroughly, to obtain a sample that is as 

representative as possible, following standard operating procedures of the 

vacuum. 

6.7. Preservation of OGSR Samples

6.7.1. Store sample collection media (e.g., adhesive lifts, swabs, or vacuum filters) in an 

airtight container immediately to reduce possible loss due to evaporation. 

6.7.2. Store samples at 0oC or lower to maximize preservation [4,5].

7. Documentation

7.1. Using hardcopies or electronic format, obtain and retain the following for a period of

time as determined by laboratory or agency policy, refer to E1492 and E3255:

7.1.1. Field notes from the collection of OGSR, including but not limited to, the 

materials used for collection, location and type of the surface(s) sampled (e.g., 

skin, shirt, glass), time elapsed between shooting incident and sample collection, 

if known, and the storage procedure employed immediately after collection, if 

known. 

7.1.2. Laboratory notes about the handling of the OGSR samples, including but not 

limited to, how the samples were stored upon arrival at the laboratory, type of 

sample (e.g., swab, tape lift, vacuum filter), duration of the time the samples were 

stored prior to analysis. 

7.1.2.1. Record any possible contamination (e.g., failure to store in an airtight 

container) or any other potentially deleterious condition (e.g., failure to 

store at proper temperature) that might compromise or affect a sample.

7.1.2.2. Record any exceptions to these procedures and reasons or justifications for 

departures from this Practice.

7.2. The laboratory shall follow other intra-laboratory protocols for documentation as 

appropriate, including duration of record retention for the field and laboratory notes 

(7.1.1 – 7.1.2).

8. Quality Assurance

8.1. Validate or verify the materials and collection process prior to use, in accordance with

Practice E3255.

8.2. Document the validation or verification in accordance with Practice E3255. 

9. Keywords

9.1. OGSR; Collection; Preservation

10. References
OSAC 2021-N-0009 Standard Practice for the 

Collection and Preservation of Organic Gunshot Residue 

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[1] J. S. Wallace. Chemical Analysis of Firearms, Ammunition, and Gunshot Residue;

International Forensic Science and Investigation Series; CRC Press: New York, 2008; pp

241-275.

[2] S. Benito, Z. Abrego, A. Sanchez, N. Unceta, M.A. Goicolea, R.J. Barrio, Characterization of

organic gunshot residues in lead-free ammunition using a new sample collection device for

liquid chromatography-quadrupole time-of-flight mass spectrometry, Forensic Sci Int 246

(2015), 79-85. 10.1016/j.forsciint.2014.11.002.

[3] A. van Eijck, E. Hogk, I. Jülch, D. Kirsch, S. Luhn, R. Nagim, R. Schumacher, D. Urbach, A.

Irwin, P. Webster, Z. Brozek-Mucha O. I. Azulay, E. Israeli, N. Levin, D. Sonenfeld, T.

Tsach, A. Zelkowics, Technical Report: Development of analytical methods for sensitive

detection and identification of organic gunshot residues (OGSR) based on liquid

chromatography-mass spectrometry (LC-MS) for routine casework,

HOME/2011/ISEC/AG/4000002504, 2017.

[4] A.L. Gassner, C. Ribeiro, J. Kobylinska, A. Zeichner, C. Weyermann, Organic gunshot

residues: Observations about sampling and transfer mechanisms, Forensic Sci Int 266 (2016),

369-78. 10.1016/j.forsciint.2016.06.029.

[5] J.D. Ropero-Miller, J.S. Morgan, S. Bell, Organic Gunshot Residue Analysis for Potential

Shooter Determination. National Institute of Justice: Forensic Technology Center of

Excellence, 2015; p 17.

[6] E. Goudsmits, G.P. Sharples, J.W. Birkett, Recent trends in organic gunshot residue analysis,

TrAC Trends in Analytical Chemistry 74 (2015), 46-57. 10.1016/j.trac.2015.05.010.

[7] A. Zeichner, N. Levin, Collection Efficiency of Gunshot Residue (GSR) Particles from Hair

and Hands Using Double-Side Adhesive Tape, Journal of Forensic Science 38 (1993), 571-

584.

[8] A. Zeichner, B. Eldar, B. Glattstein, A. Koffman, T. Tamiri, D. Muller, Vacuum Collection

of Gunpowder Residues from Clothing Worn by Shooting Suspects, and Their Analysis by

GC/TEA, IMS, and GC/MS, J Forensic Sci 48 (2003), 1-12.