ASTM D2420-23

Standard Test Method for Hydrogen Sulfide in Liquefied Petroleum (LP) Gases (Lead Acetate Method)

SIGNIFICANCE AND USE
5.1 Liquefied petroleum gases and their products of combustion must not be unduly corrosive to the materials with which they come in contact. The potential personnel exposure hazards of H2S also make the detection and measurement of hydrogen sulfide important, even in low concentrations. In addition, in some cases the odor of the gases shall not be objectionable. (See Specification D1835 and GPA 2140.)
SCOPE
1.1 This test method2 covers the detection of hydrogen sulfide in liquefied petroleum (LP) gases. The sensitivity of the test is about 4 mg/m3 (0.15 to 0.2 grain of hydrogen sulfide per 100 ft3) of gas.  
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
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: 28-Feb-2023
• ICS: 75.160.30 - Gaseous fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.H0 - Liquefied Petroleum Gas

Relations

• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D1265-23a - Standard Practice for Sampling Liquefied Petroleum (LP) Gases, Manual Method
• Effective Date: 01-Dec-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D1835-13 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 01-May-2013
• Refers: ASTM D1835-12 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 01-Dec-2012
• Refers: ASTM D1835-11 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 01-May-2011
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1835-05 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 01-Apr-2005
• Refers: ASTM D1265-04a - Standard Practice for Sampling Liquefied Petroleum (LP) Gases (Manual Method)
• Effective Date: 01-Nov-2004
• Refers: ASTM D1265-04 - Standard Practice for Sampling Liquefied Petroleum (LP) Gases (Manual Method)
• Effective Date: 01-May-2004
• Refers: ASTM D1835-03a - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 01-Nov-2003
• Refers: ASTM D1835-03 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 10-May-2003
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1835-97 - Standard Specification for Liquefied Petroleum (LP) Gases
• Effective Date: 10-Nov-1997

Overview

ASTM D2420-23 is the international standard test method for determining the presence of hydrogen sulfide in liquefied petroleum (LP) gases using the lead acetate method. Developed by ASTM International, this method is vital for ensuring that LP gases are not unduly corrosive to materials and do not pose health or safety risks due to hydrogen sulfide (H₂S) content. Hydrogen sulfide, even at low concentrations, can be hazardous to personnel and can contribute to unwanted odors or corrosion when combusted. Therefore, reliable detection and measurement are essential for quality control and regulatory compliance in the production and distribution of LP gases.

Key Topics

• Test Method Sensitivity: The method detects hydrogen sulfide at concentrations as low as 4 mg/m³ (0.15 to 0.2 grain per 100 ft³), offering reliable sensitivity for industrial needs.
• Lead Acetate Detection Principle: Vaporized LP gas is passed over moist lead acetate paper; any hydrogen sulfide reacts to form lead sulfide, resulting in a visible color change from yellow to black depending on the concentration.
• Sample Handling: Proper sampling and handling are critical. The chemical and physical properties of hydrogen sulfide may cause its concentration to change after sample collection if not handled correctly.
• Possible Interferences: While other sulfur compounds in LP gas do not interfere with the test, methyl mercaptan can cause a temporary yellow stain, which fades within five minutes and does not affect final interpretation.
• Result Interpretation: The test result is qualitative, reported as “negative” (“pass”) if there is no lasting coloration or “positive” (“fail”) if distinct coloration persists after five minutes.
• Safety and Compliance: The standard emphasizes the importance of following appropriate safety, health, and environmental practices and complying with any regulatory limitations.

Applications

ASTM D2420-23 is broadly used across the petroleum, energy, and chemical industries to assure the safe handling, storage, and delivery of LP gases such as propane, butane, and their mixtures. Key applications include:

• Quality Assurance: Routine monitoring of hydrogen sulfide levels to prevent corrosion in pipelines, storage tanks, and end-use equipment.
• Regulatory Compliance: Meeting the requirements of national and international specifications for LP gas composition (such as ASTM D1835 and GPA 2140).
• Personnel Safety: Assessing potential exposure hazards for workers and consumers by ensuring low or undetectable H₂S levels.
• Product Development and Research: Supporting the development and testing of LP gas blends by confirming acceptable sulfur compound levels.

This test method is particularly valuable for companies that produce, transport, or utilize LP gases in industrial, agricultural, or home energy systems.

Related Standards

For comprehensive LP gas quality control, ASTM D2420-23 references several related standards:

• ASTM D1193 - Specification for Reagent Water: Ensures consistency and purity of water used in the test.
• ASTM D1265 - Practice for Sampling LP Gases, Manual Method: Provides guidance on representative sample collection.
• ASTM D1835 - Specification for Liquefied Petroleum (LP) Gases: Outlines specifications for LP gas composition.
• ASTM D4175 - Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants: Offers definitions used throughout petroleum testing standards.
• GPA 2140 - Liquefied Petroleum Gas Specifications and Test Methods: Sets industry-agreed specifications for LP gas analysis.

By following ASTM D2420-23 and its referenced standards, organizations can reliably detect hydrogen sulfide in LP gases, enhance operational safety, meet regulatory requirements, and protect both infrastructure and personnel.

Keywords: ASTM D2420, hydrogen sulfide detection, LP gas testing, lead acetate method, liquefied petroleum gas, H₂S in LPG, safety, corrosion prevention, gas quality standards.

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: D2420 − 23
Standard Test Method for
Hydrogen Sulfide in Liquefied Petroleum (LP) Gases (Lead
Acetate Method)
This standard is issued under the fixed designation D2420; 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* 2.2 GPA Standard:
GPA 2140 Liquefied Petroleum Gas Specifications and Test
1.1 This test method covers the detection of hydrogen
Methods
sulfide in liquefied petroleum (LP) gases. The sensitivity of the
test is about 4 mg ⁄m (0.15 to 0.2 grain of hydrogen sulfide per
3. Terminology
100 ft ) of gas.
3.1 Definitions:
1.2 The values stated in SI units are to be regarded as
3.1.1 For definitions of terms used in this test method, refer
standard. The values given in parentheses after SI units are
to Terminology D4175.
provided for information only and are not considered standard.
3.1.2 liquefied petroleum gas (LP gas, LPG), n—a narrow
boiling range mixture of hydrocarbons consisting of propane,
1.3 This standard does not purport to address all of the
propylene, butanes and butylenes, individually or in specified
safety concerns, if any, associated with its use. It is the
combinations, with limited amounts of other hydrocarbons
responsibility of the user of this standard to establish appro-
(such as ethane) and may contain naturally occurring,
priate safety, health, and environmental practices and deter-
petroleum-derived, non-hydrocarbons.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.1 Vaporized LP gas is passed over moist lead acetate paper
Development of International Standards, Guides and Recom-
under controlled conditions. Hydrogen sulfide reacts with lead
mendations issued by the World Trade Organization Technical
acetate to form lead sulfide which produces a coloration on the
Barriers to Trade (TBT) Committee.
paper varying from yellow to black, depending upon the
amount of hydrogen sulfide present.
2. Referenced Documents
3 5. Significance and Use
2.1 ASTM Standards:
D1193 Specification for Reagent Water 5.1 Liquefied petroleum gases and their products of com-
bustion must not be unduly corrosive to the materials with
D1265 Practice for Sampling Liquefied Petroleum (LP)
which they come in contact. The potential personnel exposure
Gases, Manual Method
hazards of H S also make the detection and measurement of
D1835 Specification for Liquefied Petroleum (LP) Gases
hydrogen sulfide important, even in low concentrations. In
D4175 Terminology Relating to Petroleum Products, Liquid
addition, in some cases the odor of the gases shall not be
Fuels, and Lubricants
objectionable. (See Specification D1835 and GPA 2140.)
6. Interferences
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
6.1 Methyl mercaptan, if present, produces a transitory
Subcommittee D02.H0 on Liquefied Petroleum Gas.
yellow stain on the lead acetate paper that will fade completely
Current edition approved March 1, 2023. Published March 2023. Originally
in less than 5 min.
approved in 1965. Last previous edition approved in 2018 as D2420 – 13 (2018).
DOI: 10.1520/D2420-23.
6.2 Other sulfur compounds present in liquefied petroleum
This test method is based on Edwards, J. D., and McBride, R. S., “Lead Acetate
gas do not interfere with the test.
Test for Hydrogen Sulphide in Gas,” Technologic Papers T41, National Institute for
Standards and Technology, Aug. 9, 1914.
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 Available from Gas Processors Association (GPA), 66 American Plaza, Suite
the ASTM website. 700, Tulsa, OK 74135, http://www.gpaglobal.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2420 − 23
7. Apparatus and Materials 7.5.1 Internal surfaces of sample containers, lines and fit-
tings may be surface coated with an inert material to reduce
7.1 Apparatus for Detecting Hydrogen Sulfide in Liquefied
bare metal surfaces which could react with, or absorb, trace
Petroleum Gas, as shown in Fig. 1 or commercially available
hydrogen sulfide.
apparatus.
7.6 High–Pressure Sample Container, optional—Designed
7.2 Lead Acetate Test Paper—Commercially available test
for containing liquefied petroleum gas. An inert surface coating
paper is satisfactory. Alternatively, the test paper may be
on the inner surface of the container may be used, and is
prepared by dipping strips of smooth filter paper in 5 %
recommended.
aqueous lead acetate solution and removing the excess solution
with a clean blotter. The strips of paper shall be approximately
8. Sampling
50 mm long and 10 mm wide and contain a 3 mm hole near
8.1 Collect a representative sample by Practice D1265 using
one end so they will hang freely vertical in the test apparatus.
a clean, high–pressure sample container which is inert to
7.3 Gas Flow Indicator—Capable of measuring flow rates
hydrogen sulfide.
...

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: D2420 − 13 (Reapproved 2018) D2420 − 23
Standard Test Method for
Hydrogen Sulfide in Liquefied Petroleum (LP) Gases (Lead
Acetate Method)
This standard is issued under the fixed designation D2420; 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 Scope*
1.1 This test method covers the detection of hydrogen sulfide in liquefied petroleum (LP) gases. The sensitivity of the test is about
3 3
4 mg ⁄m (0.15 to 0.2 grain of hydrogen sulfide per 100 ft ) of gas.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
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:
D1193 Specification for Reagent Water
D1265 Practice for Sampling Liquefied Petroleum (LP) Gases, Manual Method
D1835 Specification for Liquefied Petroleum (LP) Gases
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
2.2 GPA Standard:
GPA 2140 Liquefied Petroleum Gas Specifications and Test Methods
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.H0 on Liquefied Petroleum Gas.
Current edition approved April 1, 2018March 1, 2023. Published June 2018March 2023. Originally approved in 1965. Last previous edition approved in 20132018 as
D2420 – 13.D2420 – 13 (2018). DOI: 10.1520/D2420-13R18.10.1520/D2420-23.
This test method is based on Edwards, J. D., and McBride, R. S., “Lead Acetate Test for Hydrogen Sulphide in Gas,” Technologic Papers T41, National Institute for
Standards and Technology, Aug. 9, 1914.
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 Gas Processors Association (GPA), 66 American Plaza, Suite 700, Tulsa, OK 74135, http://www.gpaglobal.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2420 − 23
3.1.2 liquefied petroleum gas (LP gas, LPG), n—a narrow boiling range mixture of hydrocarbons consisting of propane, propylene,
butanes and butylenes, individually or in specified combinations, with limited amounts of other hydrocarbons (such as ethane) and
may contain naturally occurring, petroleum-derived, non-hydrocarbons.
4. Summary of Test Method
4.1 Vaporized LP gas is passed over moist lead acetate paper under controlled conditions. Hydrogen sulfide reacts with lead acetate
to form lead sulfide which produces a coloration on the paper varying from yellow to black, depending upon the amount of
hydrogen sulfide present.
5. Significance and Use
5.1 Liquefied petroleum gases and their products of combustion must not be unduly corrosive to the materials with which they
come in contact. The potential personnel exposure hazards of H S also make the detection and measurement of hydrogen sulfide
important, even in low concentrations. In addition, in some cases the odor of the gases shall not be objectionable. (See Specification
D1835 and GPA 2140.)
6. Interferences
6.1 Methyl mercaptan, if present, produces a transitory yellow stain on the lead acetate paper that will fade completely in less than
5 min.
6.2 Other sulfur compounds present in liquefied petroleum gas do not interfere with the test.
7. Apparatus and Materials
7.1 Apparatus for Detecting Hydrogen Sulfide in Liquefied Petroleum Gas, as shown in Fig. 1 or commercially available
apparatus.
FIG. 1 Typical Apparatus for Detecting Hydrogen Sulfide in Liquefied Petroleum Gas
D2420 − 23
7.2 Lead Acetate Test Paper—Commercially available test paper is satisfactory. Alternatively, the test paper may be prepared by
dipping strips of smooth filter paper in 5 % aqueous lead acetate solution and removing the excess solution with a clean blotter.
The strips of paper shall be approximately 50 mm long and 10 mm wide and contain a 3 mm hole near one end so they will hang
freely vertical in the test apparatus.
7.3 Gas Flow Indicator—Capable of measuring flow rates in the range of 2 L to 3 L of gas per minute. A wet test meter rotameter
and mass flow controller have been found to be suitable.
7.4 Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water that meets the requirements
of Type II or III of Specification D1193, or distilled water.
7.5 Tubing—High-pressure connecting
...