ASTM E3255-21

Standard Practice for Quality Assurance of Forensic Science Service Providers Performing Forensic Chemical Analysis

SIGNIFICANCE AND USE
4.1 These are minimum standards of quality assurance applicable to forensic science service providers performing forensic chemical analysis on evidence.  
4.2 This practice is to be used by forensic science practitioners performing chemical analysis on evidence and reinforced by forensic science service provider management.
SCOPE
1.1 This practice discusses procedures for quality assurance of forensic science service providers performing forensic chemical analysis. This practice provides a framework of quality in the processing of evidence, including: maintaining a quality management system; personnel duties, qualifications, training, and education; facility considerations; evidence handling; analytical procedures; instrument and equipment performance; chemicals and reagents; casework documentation and reporting; proficiency and competency testing; method validation and verification; audits; deficiency of analysis; and documentation requirements. Annex A1 – Annex A3 provide additional procedures that are discipline-specific.  
1.2 This practice cannot replace knowledge, skills, or abilities acquired through appropriate education, training, and experience (see Practice E2917), and is to be used in conjunction with professional judgment by individuals with such discipline-specific knowledge, skills, and abilities.  
1.3 This standard 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 07.140 - Forensic science
• Technical Committee: E30 - Forensic Sciences
• Drafting Committee: E30.11 - Interdisciplinary Forensic Science Standards

Relations

• Refers: ASTM E1732-24 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Feb-2024
• Refers: ASTM E2917-24 - Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
• Effective Date: 01-Feb-2024
• Refers: ASTM E2917-19 - Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
• Effective Date: 15-Feb-2019
• Refers: ASTM E1732-19 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-Jan-2019
• Refers: ASTM E1732-18b - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Nov-2018
• Refers: ASTM E1732-18a - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Jun-2018
• Refers: ASTM E1732-18 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-May-2018
• Refers: ASTM E1732-17 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Sep-2017
• Refers: ASTM E1459-13 - Standard Guide for Physical Evidence Labeling and Related Documentation
• Effective Date: 15-Feb-2013
• Refers: ASTM E1732-12 - Standard Terminology Relating to Forensic Science
• Effective Date: 15-Jun-2012
• Refers: ASTM E1732-11a - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Oct-2011
• Refers: ASTM E1732-11b - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Oct-2011
• Refers: ASTM E1492-11 - Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
• Effective Date: 01-Jun-2011
• Refers: ASTM E1732-11 - Standard Terminology Relating to Forensic Science
• Effective Date: 01-Jun-2011
• Refers: ASTM E620-11 - Standard Practice for Reporting Opinions of Scientific or Technical Experts
• Effective Date: 01-May-2011

Overview

ASTM E3255-21: Standard Practice for Quality Assurance of Forensic Science Service Providers Performing Forensic Chemical Analysis establishes minimum quality assurance standards for laboratories and organizations involved in forensic chemical analysis. Developed by ASTM International, this standard is designed to ensure the integrity, reliability, and accuracy of forensic chemical examinations by defining core requirements for quality management systems, personnel competence, evidence handling, analytical procedures, and documentation.

For forensic science service providers, adhering to ASTM E3255-21 supports compliance with international best practices and enhances trust in forensic results presented in legal, criminal, and regulatory proceedings.

Key Topics

• Quality Management System

  • Requires a documented quality management system meeting international standards (e.g., ISO/IEC 17025, ISO/IEC 17020).
  • Mandates clear designation of quality assurance roles and ongoing system reviews.

• Personnel Qualifications and Training

  • Defines required education, duties, and training for all staff, including directors, quality assurance managers, technicians, and forensic science practitioners.
  • Requires adherence to ASTM Practice E2917 for ongoing education and competency.

• Facilities and Equipment

  • Calls for adequate, safe, and secure facilities and equipment to prevent contamination and ensure reliable chemical analysis.
  • Stipulates regular performance and maintenance monitoring for instruments and equipment.

• Evidence Integrity and Handling

  • Enforces strict evidence control measures to preserve the chain of custody and safeguard against contamination or degradation.
  • Incorporates procedures for documentation and annual evidence inventory.

• Analytical Methods and Validation

  • Requires documented, validated, and authorized analytical methods.
  • Validation and verification must address method suitability, reliability, and defined acceptance criteria.

• Chemicals and Reagents

  • Demands use of certified or verified reagents and reference materials, with full documentation and efficacy checks.

• Casework Documentation and Reporting

  • Details requirements for thorough documentation, report writing, and review to ensure transparency and reproducibility.

• Testing and Audits

  • Mandates regular proficiency and competency testing, internal audits, and documented resolutions for nonconforming work.

Applications

ASTM E3255-21 is applied by forensic laboratories and service providers performing chemical analysis on evidence from criminal investigations, civil disputes, regulatory actions, and more. Practical uses include:

• Establishing quality assurance frameworks for new or existing forensic laboratories.
• Supporting accreditation efforts under ISO/IEC 17025 or similar standards.
• Training and evaluating forensic science practitioners, technicians, and support staff.
• Developing and validating laboratory analytical methods for seized drugs, toxicology, fire debris, and other forensic chemistry disciplines.
• Ensuring the reliability of analytical results used as evidence in court or regulatory proceedings.
• Strengthening chain-of-custody protocols and case documentation for legal defensibility.

For specialized applications, Annexes provide guidance tailored to seized-drug analysis, ignitable liquid/ignitable liquid residue analysis, and toxicology, referencing supporting standards and recommended best practices.

Related Standards

Various ASTM and ISO standards are referenced within ASTM E3255-21 to support comprehensive quality management and analysis, including:

• ASTM E2917 – Practitioner Training, Continuing Education, and Professional Development
• ASTM E1459 – Physical Evidence Labeling and Documentation
• ASTM E1492 – Evidence Receiving, Documenting, Storing, and Retrieving
• ASTM E2329, E2548, E2549, E2764, E2882 – Seized-drug analysis methods and validation
• ASTM E1618, E2451 – Ignitable liquid residue analysis
• ISO/IEC 17025 – General Requirements for the Competence of Testing and Calibration Laboratories
• ISO/IEC 17020 – Requirements for the Operation of Various Types of Inspection Bodies
• ISO/IEC 17043 – Proficiency Testing
• ISO 17034 – Reference Material Producers Competence

These related standards and guidelines enable forensic laboratories to build robust, internationally recognized quality systems and analytical protocols, ensuring credibility and consistency across the forensic science community.

Keywords

Quality assurance, forensic chemical analysis, forensic science service provider, method validation, evidence handling, forensic laboratory accreditation, proficiency testing, forensic science standards, ASTM E3255-21

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3255 − 21 An American National Standard
Standard Practice for
Quality Assurance of Forensic Science Service Providers
Performing Forensic Chemical Analysis
This standard is issued under the fixed designation E3255; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E620 Practice for Reporting Opinions of Scientific or Tech-
nical Experts
1.1 This practice discusses procedures for quality assurance
E1459 Guide for Physical Evidence Labeling and Related
of forensic science service providers performing forensic
Documentation
chemical analysis. This practice provides a framework of
E1492 Practice for Receiving, Documenting, Storing, and
quality in the processing of evidence, including: maintaining a
Retrieving Evidence in a Forensic Science Laboratory
quality management system; personnel duties, qualifications,
E1732 Terminology Relating to Forensic Science
training, and education; facility considerations; evidence han-
E2917 Practice for Forensic Science Practitioner Training,
dling; analytical procedures; instrument and equipment perfor-
Continuing Education, and Professional Development
mance; chemicals and reagents; casework documentation and
Programs
reporting; proficiency and competency testing; method valida-
tion and verification; audits; deficiency of analysis; and docu- 2.2 ISO Standards:
mentation requirements. Annex A1 – Annex A3 provide ISO Guide 30 Reference materials — Selected terms and
additional procedures that are discipline-specific. definitions
ISO 17034 General requirements for the competence of
1.2 This practice cannot replace knowledge, skills, or abili-
reference material producers
ties acquired through appropriate education, training, and
ISO/IEC 17020 Conformity assessment – Requirements for
experience (see Practice E2917), and is to be used in conjunc-
the operation of various types of bodies performing
tion with professional judgment by individuals with such
inspection
discipline-specific knowledge, skills, and abilities.
ISO/IEC 17025 General requirements for the competence of
1.3 This standard does not purport to address all of the
testing and calibration laboratories
safety concerns, if any, associated with its use. It is the
ISO/IEC 17043 Conformity assessment – General require-
responsibility of the user of this standard to establish appro-
ments for proficiency testing
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
3. Terminology
1.4 This international standard was developed in accor-
3.1 Definitions—For definitions of terms that can assist in
dance with internationally recognized principles on standard-
interpreting this standard, refer to Terminology E1732.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
3.2 Definitions of Terms Specific to This Standard:
mendations issued by the World Trade Organization Technical
3.2.1 blank, n—a control where a specified component(s) is
Barriers to Trade (TBT) Committee.
not present.
2. Referenced Documents
3.2.1.1 Discussion—Blanks with various designations can
be specified, such as system blank, process blank, method
2.1 ASTM Standards:
blank, reagent blank, solvent blank, etc. Certain blanks may
also serve as a negative control.
This practice is under the jurisdiction of ASTM Committee E30 on Forensic
3.2.2 certified reference material, n—reference material
Sciences and is the direct responsibility of Subcommittee E30.11 on Interdisciplin-
(RM)characterizedbyametrologicallyvalidprocedureforone
ary Forensic Science Standards.
ormorespecifiedproperties,accompaniedbyanRMcertificate
Current edition approved Jan. 1, 2021. Published January 2021. Originally
approved in 2020. Last previous edition approved in 2020 as E3255 – 20. DOI:
10.1520/E3255-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from International Organization for Standardization (ISO), ISO
Standards volume information, refer to the standard’s Document Summary page on Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
the ASTM website. Geneva, Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3255 − 21
that provides the value of the specified property, its associated 5.2.1 Personnel responsible for the quality management
uncertainty, and a statement of metrological traceability. system (that is, quality assurance manager) shall be clearly
ISO Guide 30 designated.
5.2.2 The quality management system shall cover all pro-
3.2.3 equipment, n—set of laboratory tools, apparatus, and
cedures and reports associated with analysis.
hardware used to process test items (for example, ovens,
5.2.3 The quality management system shall conform to an
beakers, pipettes, vortexers, fume hoods, etc.)
international standard, such as ISO/IEC 17025 or ISO/IEC
3.2.4 forensic science practitioner, n—anindividualwho(1)
17020.
applies scientific or technical practices to the recognition,
collection, analysis, or interpretation of evidence for criminal
6. Personnel
and civil law or regulatory issues; and (2) issues test results,
6.1 Personnel shall have defined responsibilities, duties,
provides interpretations, or opinions through reports or testi-
educational requirements and required skills.
mony with respect to such evidence. derived from
Defining Forensic Science and Related Terms
6.2 Forensic science service providers shall conform to
3.2.5 forensic science service provider, n—a forensic sci- Practice E2917.
ence agency or forensic science practitioner providing forensic
6.3 Designated key personnel and responsibilities shall be
science services. derived from
established and maintained. An individual (however named)
Defining Forensic Science and Related Terms
can be responsible for more than one of the duties detailed in
3.2.6 instrument, n—equipment capable of performing mea-
6.4 to 6.9.
surements used to generate analytical data (for example,
6.4 Director—A designated person who is responsible for
GC-MS, IR, NMR, balances, etc.).
the overall operation and administration of the forensic science
3.2.7 interlaboratory comparison, n—organization, perfor-
service provider, including the employment and training of
mance and evaluation of measurements or tests on the same or
personnelandassuringcompliancewithapplicableregulations.
similar items by two or more laboratories in accordance with
6.5 Quality Assurance Manager—Adesignated person who
predetermined conditions. ISO/IEC 17043
is responsible for maintaining the quality management system
3.2.8 intralaboratory comparison, n—organization, perfor-
(including an annual review of the program) and who ensures
mance and evaluation of measurements or tests on the same or
conformance with the program.
similar within the same laboratory in accordance with prede-
6.6 Technical Support Personnel—A person who performs
termined conditions. ISO/IEC 17025
basic forensic science duties (for example, calibration checks,
3.2.9 negative control, n—a material of established origin
making solutions, glassware washing, etc.), but does not
that is used to confirm that a procedure does not produce an
analyze evidence. Technical support personnel shall:
unintended result.
6.6.1 Have education, skills, and abilities commensurate
3.2.10 positive control, n—a material of established origin with their responsibilities; and
that is used to confirm that a procedure will produce the
6.6.2 Have on-the-job training specific to the responsibili-
expected result. ties of their position.
3.2.11 standardized method, n—a method published by a
6.7 Technician—A person who analyzes evidence, but does
recognized international, regional, or national standard devel-
not issue reports of analytical results or interpretations. Tech-
opment organization (for example,ASTM,ASB,AOAC, etc.).
nicians shall:
6.7.1 Have education, skills, and abilities commensurate
4. Significance and Use
with their responsibilities; and
4.1 These are minimum standards of quality assurance
6.7.2 Have formal training in evidence handling and those
applicable to forensic science service providers performing
aspects of their duties specific to analysis. These include:
forensic chemical analysis on evidence.
(1) Successful and documented completion of written or
oral examinations,
4.2 This practice is to be used by forensic science practitio-
(2) Successful and documented completion of competency
ners performing chemical analysis on evidence and reinforced
testing, and
by forensic science service provider management.
(3) Successful and documented completion of a moot/
5. Quality Management System
mock court exercise.
5.1 It is the goal of a forensic science service provider’s
6.8 Forensic Science Practitioner—A designated person
evidence analysis program to provide customers with high
who may be authorized to: examine and analyze materials, or
quality analyses that produce reliable and accurate results.
direct such examinations to be performed; interpret data, issue
reports for court or investigative purposes; and conduct,
5.2 A documented quality management system shall be
method validation, training, and technical review of reports.
established and maintained.
Forensic science practitioners shall:
6.8.1 Meet all the requirements of a technician (6.7), and
National Commission on Forensic Science, Defining Forensic Science and
6.8.2 Have at least a bachelor’s degree or equivalent
Related Terms,May2016,availablefromhttps://www.justice.gov/archives/ncfs/file/
786571/download. (generally, a four-year postsecondary degree) in a natural or
E3255 − 21
physical science. The individual shall have successfully com- 8.6 Disposition of Evidence—Records shall be kept regard-
pleted lecture and laboratory classes’ in chemistry specific to ing the disposition of all items of evidence (see Practice
their particular discipline, and E1492).
6.8.3 Conform to Practice E2917.
9. Method Validation and Verification
6.9 Technical Leader—A designated person or team of
individuals who have the overall responsibility and authority 9.1 Validation is required to demonstrate that methods are
for the technical operations associated with evidence analyses. suitable for their intended purpose.
Technical operations include maintaining protocols, develop-
9.2 Forensic science service providers adopting methods
inganalyticalmethodology,conductingmethodvalidation,and
validated elsewhere shall verify the validity and reliability of
performing technical review of reports. The technical leader
those methods used in their environment, with their
shall:
instrumentation, equipment, reagents and chemicals, and fo-
6.9.1 Meet all the requirements of a forensic science prac-
rensic science practitioners prior to use.
titioner (6.8), and
9.3 New methods developed for characterization,
6.9.2 Have a minimum of three (3) years of experience as a
identification, and comparison of chemicals shall be based on
qualified forensic science practitioner performing independent
accepted scientific principles. The forensic science service
evidence analyses in the specific discipline.
provider shall perform validation studies to establish both the
method’s validity and reliability prior to use in casework.
7. Physical Plant
9.3.1 Minimum acceptance criteria shall be established for
7.1 Forensic science service providers shall provide:
method performance and be described along with means for
7.1.1 Adequate safety and security for personnel and opera-
demonstrating compliance.
tions;
9.4 Method validation and verifications shall address
7.1.2 Facilities that meet required health and safety stan-
selectivity, precision, and other relevant performance charac-
dards and applicable building codes;
teristics and limitations.
7.1.3 Suitable space to perform required analytical func-
9.4.1 Validations and verifications involving quantitative
tions and prevent contamination;
analysis shall also address limits of detections, lower limit of
7.1.4 Environmental and procedural controls to prevent
quantitation, linearity, accuracy, and uncertainty of the mea-
incidental contamination;
surement process.
7.1.5 Engineering devices and personal protective equip-
9.5 Validation and verifications shall be approved by the
ment (for example, chemical fume hoods, safety showers,
technical leader or other designated personnel prior to use in
gloves, safety glasses, etc.) to protect personnel from chemical
casework.
hazards; and
7.1.6 Facilities that ensure safe and secure storage of
9.6 Validation and verification data and documentation shall
evidence, chemicals, reagents, reference materials and records.
be maintained.
8. Evidence Control
10. Analytical Procedures
8.1 Forensic science service providers shall follow a docu-
10.1 Analytical Procedures:
mented control system to ensure the integrity of evidence.
10.1.1 Forensic science service providers shall follow
8.2 See Guide E1459 for physical evidence labeling and documented, validated, and authorized analytical methods.
10.1.1.1 The technical leader or other designated individual
related documentation.
shall be responsible for evaluation and authorization of the
8.3 See Practice E1492 for receiving, documenting, storing,
analytical procedures used by the forensic science service
and retrieving evidence.
provider, including reviews of method validations and verifi-
8.4 Integrity of Evidence—Evidence shall be properly se-
cations. All evaluations and authorizations shall be docu-
cured and sealed. Appropriate storage conditions shall ensure
mented and retained.
that, insofar as possible, the composition of evidentiary mate-
10.1.1.2 A chemical/material identification, quantification
rial is not altered. The integrity of the evidence shall be
orcomparisonshallbebasedonspecificcharacteristicsdefined
protected in ways that safeguard against loss, deterioration or
inthevalidatedmethod,anddecisionsonthetype/sourceofthe
contamination.Alterationoftheevidenceorpackagingshallbe
material should be based on pre-established decision-
documented.
thresholds.
10.1.1.3 Relevant limitations of chemical/material identifi-
8.5 Accounting for Evidence—Evidence that is maintained
cations or comparisons shall be evaluated and reported.
by the forensic science service provider shall be inventoried, at
10.1.1.4 Forensic science service providers shall have in
a minimum, annually.
place protocols for the sampling of evidence.
10.1.1.5 When applicable, forensic science service provid-
ers should employ a statistically based protocol when an
Forensic Science Laboratories: Handbook for Facility Planning, Design,
inference is to be made regarding a specified proportion of a
Construction, and Relocation, June 2013, available from https://tsapps.nist.gov/
publication/get_pdf.cfm?pub_id=913987. submission for qualitative or quantitative determinations.
E3255 − 21
10.1.2 Published or standardized methods are recom- able. External reference data shall be assessed and demon-
mended. Laboratory-developed or modified methods can also strated to be fit for purpose. Factors include:
be used. (1) Origin of the data;
(2) Validation of the data;
10.1.2.1 The forensic science service provider shall verify
(3) Peer review of the data; and
published or standardized methods by in-house performance
(4) Comparability of analytical conditions.
testing.
10.1.6.3 Structural elucidation techniques, when applicable
10.1.2.2 The use of laboratory-developed or modified meth-
by discipline, and when neither reference materials nor exter-
ods shall be validated and approved by the technical leader or
nal reference data are available. Structural elucidation tech-
other designated individual according to forensic science
niques may be employed by forensic science practitioners that
service provider policy.
are competent in structural elucidation interpretation.
10.1.3 Work practices shall be established to prevent con-
10.2 Assessment of Reference Materials:
tamination of evidence during analysis.
10.2.1 Forensic science service providers shall have a pro-
10.1.3.1 The processing of trace/residue samples should be
cess for assessing that reference materials are fit for purpose.
separated in space from bulk evidence submissions to prevent
10.2.1.1 Assessments are not required for reference materi-
incidental contamination. If space does not allow for this, then
als obtained from a provider accredited under ISO 17034.
the processing of bulk and trace/residue samples shall be
10.2.1.2 The assessment and purpose (for example, qualita-
separated by time with thorough cleaning between processing
steps. tive or quantitative) of a reference material shall be docu-
mented. The documentation shall include: identity; source;
10.1.3.2 Forensic science practitioners shall take measures
assigneduniqueidentifier;dateandnameoftheindividualwho
to be assured that identifications are correct (for example,
performed the assessment; and verification test data.
excluding contamination, instrument carryover, etc.) and relate
10.2.1.3 Tobefitforpurpose,referencematerialsshallmeet
to the correct submission.
minimum specifications defined in the forensic science service
10.1.4 Forensic science service providers shall follow docu-
provider’s validated methods.
mented procedures for the evaluation and acceptance of data
10.2.1.4 The assessment shall be performed on each lot of
based on the method utilized.
reference materials.
10.1.5 Forensic science service providers shall monitor
10.2.1.5 The assessment shall be completed prior to case-
analytical processes using appropriate blanks, positive and
work analysis.
negative controls and reference materials.
10.2.2 Reference materials shall only be used for the pur-
10.1.5.1 Negative controls shall be run concurrently with
pose defined by the forensic science service provider. For
evidence to demonstrate that the sampling devices, chemicals,
example, a reference material may be deemed suitable for
instruments and extraction processes do not result in contami-
qualitative but not quantitative determinations.
nation of the evidence.
10.2.2.1 Fit for purpose for qualitative work requires an
10.1.5.2 The forensic science service provider shall have a
assessment of chemical identity. Examples of verification of
procedure for routinely testing the reliability of the analytical
chemical identity by analysis include:
processes with known reference materials (positive control).
(1) Comparison of the results to peer-reviewed published
This can be done concurrently with each analysis or on a
data,
predefined schedule.
(2) Dataproducedbyanaccreditedforensicscienceservice
10.1.6 Referencem
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E3255 − 20 E3255 − 21
Standard Practice for
Quality Assurance of Forensic Science Service Providers
Performing Forensic Chemical Analysis
This standard is issued under the fixed designation E3255; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice discusses procedures for quality assurance of forensic science service providers performing forensic chemical
analysis. This practice provides a framework of quality in the processing of evidence, including: maintaining a quality management
system; personnel duties, qualifications, training, and education; facility considerations; evidence handling; analytical procedures;
instrument and equipment performance; chemicals and reagents; casework documentation and reporting; proficiency and
competency testing; method validation and verification; audits; deficiency of analysis; and documentation requirements. Annex A1
– Annex A3 provide additional procedures that are discipline-specific.
1.2 This practice cannot replace knowledge, skills, or abilities acquired through appropriate education, training, and experience
(see Practice E2917), and is to be used in conjunction with professional judgment by individuals with such discipline-specific
knowledge, skills, and abilities.
1.3 This standard 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E620 Practice for Reporting Opinions of Scientific or Technical Experts
E1459 Guide for Physical Evidence Labeling and Related Documentation
E1492 Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
E1732 Terminology Relating to Forensic Science
E2917 Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs
2.2 ISO Standards:
ISO Guide 30 Reference Materialsmaterials — Selected Termsterms and Definitionsdefinitions
This practice is under the jurisdiction of ASTM Committee E30 on Forensic Sciences and is the direct responsibility of Subcommittee E30.11 on Interdisciplinary
Forensic Science Standards.
Current edition approved Oct. 1, 2020Jan. 1, 2021. Published October 2020January 2021. Originally approved in 2020. Last previous edition approved in 2020 as E3255
– 20. DOI: 10.1520/E3255-20.10.1520/E3255-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E3255 − 21
ISO 17034 General Requirementsrequirements for the Competence of Reference Material Producerscompetence of reference
material producers
ISO/IEC 17020 Conformity assessment – Requirements for the operation of various types of bodies performing inspection
ISO/IEC 17025 General Requirementsrequirements for the Competencecompetence of Testingtesting and Calibration Labora-
toriescalibration laboratories
ISO/IEC 17043 Conformity assessment – General requirements for proficiency testing
3. Terminology
3.1 Definitions—For definitions of terms that can assist in interpreting this standard, refer to Terminology E1732.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 blank, n—a control where a specified component(s) is not present.
3.2.1.1 Discussion—
Blanks with various designations can be specified, such as system blank, process blank, method blank, reagent blank, solvent
blank, etc. Certain blanks may also serve as a negative control.
3.2.2 certified reference material, n—reference material (RM) characterized by a metrologically valid procedure for one or more
specified properties, accompanied by an RM certificate that provides the value of the specified property, its associated uncertainty,
and a statement of metrological traceability.
ISO Guide 30
3.2.3 equipment, n—set of laboratory tools, apparatus, and hardware used to process test items (for example, ovens, beakers,
pipettes, vortexers, fume hoods, etc.)
3.2.4 forensic science practitioner, n—an individual who (1) applies scientific or technical practices to the recognition, collection,
analysis, or interpretation of evidence for criminal and civil law or regulatory issues; and (2) issues test results, provides
interpretations, or opinions through reports or testimony with respect to such evidence. derived from
Defining Forensic Science and Related Terms
3.2.5 forensic science service provider, n—a forensic science agency or forensic science practitioner providing forensic science
services. derived from
Defining Forensic Science and Related Terms
3.2.6 instrument, n—equipment capable of performing measurements used to generate analytical data (for example, GC-MS, IR,
NMR, balances, etc.).
3.2.7 interlaboratory comparison, n—organization, performance and evaluation of measurements or tests on the same or similar
items by two or more laboratories in accordance with predetermined conditions. ISO/IEC 17043
3.2.8 intralaboratory comparison, n—organization, performance and evaluation of measurements or tests on the same or similar
within the same laboratory in accordance with predetermined conditions. ISO/IEC 17025
3.2.9 negative control, n—a material of established origin that is used to confirm that a procedure does not produce an unintended
result.
3.2.10 positive control, n—a material of established origin that is used to confirm that a procedure will produce the expected result.
3.2.11 reference material, n—material, sufficiently homogeneous and stable with respect to one or more specific properties, which
has been established to be fit for its intended use in a measurement process. ISO Guide 30
National Commission on Forensic Science, Defining Forensic Science and Related Terms, May 2016, available from https://www.justice.gov/archives/ncfs/file/786571/
download.
E3255 − 21
3.2.11 standardized method, n—a method published by a recognized international, regional, or national standard development
organization (for example, ASTM, ASB, AOAC, etc.).
4. Significance and Use
4.1 These are minimum standards of quality assurance applicable to forensic science service providers performing forensic
chemical analysis on evidence.
4.2 This practice is to be used by forensic science practitioners performing chemical analysis on evidence and reinforced by
forensic science service provider management.
5. Quality Management System
5.1 It is the goal of a forensic science service provider’s evidence analysis program to provide customers with high quality
analyses that produce reliable and accurate results.
5.2 A documented quality management system shall be established and maintained.
5.2.1 Personnel responsible for the quality management system (that is, quality assurance manager) shall be clearly designated.
5.2.2 The quality management system shall cover all procedures and reports associated with analysis.
5.2.3 The quality management system shall conform to an international standard, such as ISO/IEC 17025 or ISO/IEC 17020.
6. Personnel
6.1 Personnel shall have defined responsibilities, duties, educational requirements and required skills.
6.2 Forensic science service providers shall conform to Practice E2917.
6.3 Designated key personnel and responsibilities shall be established and maintained. An individual (however named) can be
responsible for more than one of the duties detailed in 6.4 to 6.9.
6.4 Director—A designated person who is responsible for the overall operation and administration of the forensic science service
provider, including the employment and training of personnel and assuring compliance with applicable regulations.
6.5 Quality Assurance Manager—A designated person who is responsible for maintaining the quality management system
(including an annual review of the program) and who ensures conformance with the program.
6.6 Technical Support Personnel—A person who performs basic forensic science duties (for example, calibration checks, making
solutions, glassware washing, etc.), but does not analyze evidence. Technical support personnel shall:
6.6.1 Have education, skills, and abilities commensurate with their responsibilities; and
6.6.2 Have on-the-job training specific to the responsibilities of their position.
6.7 Technician—A person who analyzes evidence, but does not issue reports of analytical results or interpretations. Technicians
shall:
6.7.1 Have education, skills, and abilities commensurate with their responsibilities; and
6.7.2 Have formal training in evidence handling and those aspects of their duties specific to analysis. These include:
(1) Successful and documented completion of written or oral examinations,
(2) Successful and documented completion of competency testing, and
E3255 − 21
(3) Successful and documented completion of a moot/mock court exercise.
6.8 Forensic Science Practitioner—A designated person who may be authorized to: examine and analyze materials, or direct such
examinations to be performed; interpret data, issue reports for court or investigative purposes; and conduct, method validation,
training, and technical review of reports. Forensic science practitioners shall:
6.8.1 Meet all the requirements of a technician (6.7), and
6.8.2 Have at least a bachelor’s degree or equivalent (generally, a four-year postsecondary degree) in a natural or physical science.
The individual shall have successfully completed lecture and laboratory classes’ in chemistry specific to their particular discipline,
and
6.8.3 Conform to Practice E2917.
6.9 Technical Leader—A designated person or team of individuals who have the overall responsibility and authority for the
technical operations associated with evidence analyses. Technical operations include maintaining protocols, developing analytical
methodology, conducting method validation, and performing technical review of reports. The technical leader shall:
6.9.1 Meet all the requirements of a forensic science practitioner (6.8), and
6.9.2 Have a minimum of three (3) years of experience as a qualified forensic science practitioner performing independent
evidence analyses in the specific discipline.
7. Physical Plant
7.1 Forensic science service providers shall provide:
7.1.1 Adequate safety and security for personnel and operations;
7.1.2 Facilities that meet required health and safety standards and applicable building codes;
7.1.3 Suitable space to perform required analytical functions and prevent contamination;
7.1.4 Environmental and procedural controls to prevent incidental contamination;
7.1.5 Engineering devices and personal protective equipment (for example, chemical fume hoods, safety showers, gloves, safety
glasses, etc.) to protect personnel from chemical hazards; and
7.1.6 Facilities that ensure safe and secure storage of evidence, chemicals, reagents, reference materials and records.
8. Evidence Control
8.1 Forensic science service providers shall follow a documented control system to ensure the integrity of evidence.
8.2 See Guide E1459 for physical evidence labeling and related documentation.
8.3 See Practice E1492 for receiving, documenting, storing, and retrieving evidence.
8.4 Integrity of Evidence—Evidence shall be properly secured and sealed. Appropriate storage conditions shall ensure that, insofar
as possible, the composition of evidentiary material is not altered. The integrity of the evidence shall be protected in ways that
safeguard against loss, deterioration or contamination. Alteration of the evidence or packaging shall be documented.
8.5 Accounting for Evidence—Evidence that is maintained by the forensic science service provider shall be inventoried, at a
minimum, annually.
Forensic Science Laboratories: Handbook for Facility Planning, Design, Construction, and Relocation, June 2013, available from https://tsapps.nist.gov/publication/
get_pdf.cfm?pub_id=913987.
E3255 − 21
8.6 Disposition of Evidence—Records shall be kept regarding the disposition of all items of evidence (see Practice E1492).
9. Method Validation and Verification
9.1 Validation is required to demonstrate that methods are suitable for their intended purpose.
9.2 Forensic science service providers adopting methods validated elsewhere shall verify the validity and reliability of those
methods used in their environment, with their instrumentation, equipment, reagents and chemicals, and forensic science
practitioners prior to use.
9.3 New methods developed for characterization, identification, and comparison of chemicals shall be based on accepted scientific
principles. The forensic science service provider shall perform validation studies to establish both the method’s validity and
reliability prior to use in casework.
9.3.1 Minimum acceptance criteria shall be established for method performance and be described along with means for
demonstrating compliance.
9.4 Method validation and verifications shall address selectivity, precision, and other relevant performance characteristics and
limitations.
9.4.1 Validations and verifications involving quantitative analysis shall also address limits of detections, lower limit of
quantitation, linearity, accuracy, and uncertainty of the measurement process.
9.5 Validation and verifications shall be approved by the technical leader or other designated personnel prior to use in casework.
9.6 Validation and verification data and documentation shall be maintained.
10. Analytical Procedures
10.1 Analytical Procedures:
10.1.1 Forensic science service providers shall follow documented, validated, and authorized analytical methods.
10.1.1.1 The technical leader or other designated individual shall be responsible for evaluation and authorization of the analytical
procedures used by the forensic science service provider, including reviews of method validations and verifications. All evaluations
and authorizations shall be documented and retained.
10.1.1.2 A chemical/material identification, quantification or comparison shall be based on specific characteristics defined in the
validated method, and decisions on the type/source of the material should be based on pre-established decision-thresholds.
10.1.1.3 Relevant limitations of chemical/material identifications or comparisons shall be evaluated and reported.
10.1.1.4 Forensic science service providers shall have in place protocols for the sampling of evidence.
10.1.1.5 When applicable, forensic science service providers should employ a statistically based protocol when an inference is to
be made regarding a specified proportion of a submission for qualitative or quantitative determinations.
10.1.2 Published or standardized methods are recommended. Laboratory-developed or modified methods can also be used.
10.1.2.1 The forensic science service provider shall verify published or standardized methods by in-house performance testing.
10.1.2.2 The use of laboratory-developed or modified methods shall be validated and approved by the technical leader or other
designated individual according to forensic science service provider policy.
10.1.3 Work practices shall be established to prevent contamination of evidence during analysis.
E3255 − 21
10.1.3.1 The processing of trace/residue samples should be separated in space from bulk evidence submissions to prevent
incidental contamination. If space does not allow for this, then the processing of bulk and trace/residue samples shall be separated
by time with thorough cleaning between processing steps.
10.1.3.2 Forensic science practitioners shall take measures to be assured that identifications are correct (for example, excluding
contamination, instrument carryover, etc.) and relate to the correct submission.
10.1.4 Forensic science service providers shall follow documented procedures for the evaluation and acceptance of data based on
the method utilized.
10.1.5 Forensic science service providers shall monitor analytical processes using appropriate blanks, positive and negative
controls and reference materials.
10.1.5.1 Negative controls shall be run concurrently with evidence to demonstrate that the sampling devices, chemicals,
instruments and extraction processes do not result in contamination of the evidence.
10.1.5.2 The forensic science service provider shall have a procedure for routinely testing the reliability of the analytical processes
with known reference materials (positive control). This can be done concurrently with each analysis or on a predefined schedule.
10.1.6 Reference materials and associated data shall be used to demonstrate the reliability of test results. A positive test result shall
meet the acceptance criteria defined in the method validation and operating protocol. In descending order of preference, the
acceptance criteria should be based on:
10.1.6.1 Comparison of instrumental test/case sample data to suitable reference material data analyzed under the same analytical
conditions (that is, instrument, instrumental methods, and stationary phase). If reference material data is collected on a different
instrument than the test/case sample, it shall be demonstrated that both instruments produce comparable data. The reference
material may be analyzed:
(1) Contemporaneously with test/case sample (for example, same sequence/batch);
(2) As part of routine quality control (for example, daily check solutions); or
(3) At a previous date (for example, method validation, internal reference collection).
10.1.6.2 Comparison of instrumental test/case sample data to external reference data when a reference material is unavailable.
External reference data shall be assessed and demonstrated to be fit for purpose. Factors include:
(1) Origin of the data;
(2) Validation of the data;
(3) Peer review of the data; and
(4) Comparability of analytical conditions.
10.1.6.3 Structural elucidation techniques, when applicable by discipline, and when neither reference materials nor external
reference data are available. Structural elucidation techniques may be employed by forensic science practitioners that are
competent in structural elucidation interpretation.
10.2 Assessment of Reference Materials:
10.2.1 Forensic science service providers shall have a process for assessing that reference materials are fit for purp
...