Standard Practice for the Collection and

Preservation of Organic Gunshot Residue

Standard Practice for the

Collection and

Preservation of Organic

Gunshot Residue

Ignitable Liquids, Explosives, & Gunshot Residue Subcommittee

Chemistry: Trace Evidence Scientific Area Committee

Organization of Scientific Area Committees (OSAC) for Forensic Science 

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Standard Practice for the Collection and

Preservation of Organic Gunshot Residue

Draft OSAC Proposed Standard

OSAC 2021-N-0009

Standard Practice for the Collection

and Preservation of Organic Gunshot

Residue

Prepared by 

Ignitable Liquids, Explosives, & Gunshot Residue Subcommittee

Version: 1.0 

January 2021 

Disclaimer: 

Disclaimer:This OSAC Proposed Standard was written by the Ignitable Liquids, Explosives, & 

Gunshot Residue 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 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. 

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Standard Practice for the Collection and

Preservation of Organic Gunshot Residue

Standard Practice for the Collection and Preservation of Organic Gunshot Residue

1. Scope

1.1. This standard 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 standard practice cannot replace knowledge, skill, or abilities acquired through

appropriate education, training, or experience (Practice E2917), and should be used in

conjunction with professional judgement by individuals with such discipline-specific

knowledge, skills and abilities.

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

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

appropriate safety and health practices and determine the applicability of regulatory

limitations prior to use.

2. Referenced Documents

2.1. ASTM Standards:

2.1.1. E1492 Standard Practice for Receiving, Documenting, Storing, and Retrieving

Evidence in a Forensic Science Laboratory

2.1.2. E1588 Standard Practice for Gunshot Residue Analysis by Scanning Electron

Microscopy/Energy Dispersive X-Ray Spectrometry.

2.1.3. E1732 Standard Terminology Relating to Forensic Science

2.1.4. E2917 Standard Practice for Forensic Science Practitioner Training, Continuing

Education, and Professional Development Programs.

2.1.5. E2998 Standard Practice for Characterization and Classification of Smokeless

Powders.

2.1.6. E2999 Standard Test Method for Analysis of Organic Compounds in Smokeless

Powder by Gas Chromatography-Mass Spectrometry and Fourier Transform

Infrared Spectroscopy

2.1.7. WK56998 Standard Terminology Relating to the Examination of Explosives.

3. Terminology

Definitions – For definitions of terms that can assist in interpreting

this standard, refer to Terminology E1732 and WK 56998.

Definitions of terms specific to this standard”

3.1.1. 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.

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Standard Practice for the Collection and

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

that are organic compounds.

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

be inorganic or organic in nature.

3.1.4. 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 standard provides guidance on best practices and should always be verified in

conjunction with a laboratory’s standard operating procedures.

4.4. Sampling from individuals suspected to have discharged a firearm may be subject to

legislation in some jurisdictions.

4.5. This standard 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.

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Standard Practice for the Collection and

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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, provided that their

effectiveness and suitability for OGSR collection is validated prior to use [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. 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.

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

skin and clothing.

6.1.2. 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.

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

6.2. Use a separate sampling device for each surface (e.g., left hand and right hands) to

maximize sample recovery [4,6].

6.3. Adhesive tape lifts

6.3.1. 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. The effectiveness and

suitability of other adhesive tapes should be validated prior to use.

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

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

6.4. Swabbing

6.4.1. Use dry or wet swabs to collect samples from the surface of interest.

6.4.1.1. If wet swabbing, suitable solvents include ethanol and isopropanol.

Note (1): Acetone and acetonitrile are not recommended for extended contact

with skin.

Note (2): Certain solvents can dissolve other compounds in the swab material

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

6.4.2. 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].

6.5. Vacuuming

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

procedure in section 6.3.1 to collect IGSR [8].

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Standard Practice for the Collection and

Preservation of Organic Gunshot Residue

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

representative as possible, following standard operating procedures of the

vacuum.

6.6. Preservation of OGSR Samples

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

airtight container immediately to reduce possible loss due to evaporation.

6.6.2. 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 the individual laboratory:

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

materials used for collection, location of the surfaces sampled, time elapsed

between shooting incident and sample collection, and the storage procedure

employed immediately after collection.

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

limited to how the sample was stored upon arrival at the laboratory, duration of

the time the samples were stored from receipt and prior to analysis.

8. Keywords

8.1. OGSR; Collection; Preservation

9. References

[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.

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Standard Practice for the Collection and

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[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.

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