ASTM D6273-98(2003)

Standard Test Methods for Natural Gas Odor Intensity

SIGNIFICANCE AND USE
Federal regulations4 state: “A combustible gas in a distribution line must contain a natural odorant or be odorized so that at a concentration in air of one-fifth of the lower explosive limit, the gas is readily detectable by a person with a normal sense of smell.” These regulations state further that “each operator shall conduct periodic sampling of combustible gases to assure the proper concentration of odorant in accordance with this section.” Additionally, a number of states have enacted legislation that requires natural gas to be odorized so that it is detectable at concentrations less than one fifth of the lower explosive limit.5 While regulations do not specify the exact method for determining compliance, it has been documented that compliance testing must be olfactory in nature.6  
These test methods cover procedures to measure the odor level of natural gas by way of olfactory determination. No direct correlation may be ascertained between these test methods and those methods available or under development that quantitatively measure the concentration of sulfur compounds in natural gas.
These test methods outline general procedures to measure the odor detection levels of natural gas. It is the responsibility of persons using these test methods to develop and maintain equipment and specific operating procedures to ensure public safety and compliance with all appropriate regulations.
SCOPE
1.1 These test methods cover the procedures for determining the odor intensity of natural gas through the use of instruments that dilute and mix the sampled natural gas with air. The mixed gas stream is then sniffed by the operator for the purpose of determining the threshold detection level or the readily detection level, or both, for odorant in the natural gas stream.  
1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Sep-2003
• ICS: 75.060 - Natural gas
• Technical Committee: D03 - Gaseous Fuels

Relations

• Replaces: ASTM D6273-98 - Standard Test Methods for Natural Gas Odor Intensity
• Effective Date: 10-Sep-2003
• Replaced By: ASTM D6273-08 - Standard Test Methods for Natural Gas Odor Intensity
• Effective Date: 01-May-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D6273–98 (Reapproved 2003)
Standard Test Methods for
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Natural Gas Odor Intensity
This standard is issued under the fixed designation D 6273; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 high pressure, n—for the purpose of these test meth-
ods,highpressurereferstonaturalgaspressuregreaterthanthe
1.1 These test methods cover the procedures for determin-
maximum inlet pressure specified by the manufacturer of the
ing the odor intensity of natural gas through the use of
gas dilution apparatus.
instruments that dilute and mix the sampled natural gas with
3.2.2 intensity, n—the magnitude of odor perceived by the
air.The mixed gas stream is then sniffed by the operator for the
operator.
purpose of determining the threshold detection level or the
3.2.3 low pressure, n—for the purpose of these test meth-
readily detection level, or both, for odorant in the natural gas
ods, low pressure refers to natural gas pressure less than or
stream.
equal to the maximum inlet pressure specified by the manu-
1.2 This standard does not purport to address all of the
facturer of the gas dilution apparatus.
safety concerns, if any, associated with its use. It is the
3.2.4 operator(s), n—the person(s) performing the testing
responsibility of the user of this standard to establish appro-
described in these test methods. Because of the nature of the
priate safety and health practices and determine the applica-
testing described herein, the operator shall be qualified to
bility of regulatory limitations prior to use.
perform this work (see 5.2).
2. Referenced Documents
3.2.5 readily detectable level, n—the concentration of natu-
ral gas and odorant mixture in air which the operator is able to
2.1 ASTM Standards:
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detect and identify natural gas odor.
D 4150 Terminology Relating to Gaseous Fuels
2
3.2.6 threshold detection level, n—the concentration of
D 5287 Practice forAutomatic Sampling of Gaseous Fuels
natural gas and odorant mixture in air which the operator is
E 253 Terminology Relating to Sensory Evaluation of Ma-
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barely able to detect an odor.
terials and Products
3.3 For definitions of terms related to natural gas that are
3. Terminology
used in these test methods, refer to Practice D 5287.
3.4 For definitions of terms related to olfactory testing that
3.1 Definitions:
are used in these test methods, refer to Terminology E 253.
3.1.1 odorant, n—sulfur-bearing compound that gives natu-
ralgasadistinctiveodor.Forthepurposeofthesetestmethods,
4. Significance and Use
natural gas odorants may be compounds that are present at the
4
4.1 Federal regulations state: “A combustible gas in a
wellhead or commercial mixtures that are added to the gas
distribution line must contain a natural odorant or be odorized
stream, or both.
so that at a concentration in air of one-fifth of the lower
3.1.2 olfactory fatigue, n—desensitization of the sense of
explosive limit, the gas is readily detectable by a person with
smell through either prolonged exposure or repeated exposure
a normal sense of smell.” These regulations state further that
over a short period of time to an odor, a mixture of odors, or
“each operator shall conduct periodic sampling of combustible
series of odors.
gases to assure the proper concentration of odorant in accor-
3.1.3 sniff, vi—smell or snuff with short, audible inhala-
dance with this section.”Additionally, a number of states have
tions.
enacted legislation that requires natural gas to be odorized so
3.2 Definitions of Terms Specific to This Standard:
that it is detectable at concentrations less than one fifth of the
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lower explosive limit. While regulations do not specify the
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These test methods are under the jurisdiction of Committee D03 on Gaseous
Fuels and is the direct responsibility of Subcommittee D03.05 on Determination of
Special Constituents of Gaseous Fuels.
4
Current edition approved Sept. 10, 2003. Published October 2003. Originally 49 CFR Part 192.625.
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approved in 1998. Last previous edition approved in 1998 as D 6273 – 98. For example, Massachusetts Section 192.625 MFS Standards requires that “.
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Annual Book of ASTM Standards, Vol 05.06. a concentration of fifteen hundredths of one percent gas in the air is readily
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Annual Book of ASTM Standards, Vol 15.08. perceptible to the normal or average olfactory senses of a person . .”
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D6273–98 (2003)
exact method for determining compliance, it has been
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