ASTM D4490-96(2016)
(Practice)Standard Practice for Measuring the Concentration of Toxic Gases or Vapors Using Detector Tubes
Standard Practice for Measuring the Concentration of Toxic Gases or Vapors Using Detector Tubes
SIGNIFICANCE AND USE
5.1 The Federal Occupational Safety and Health Administration, in 29 CFR 1910, designates that certain gases and vapors must not be present in workplace atmospheres at concentrations above specific values.
5.2 This practice will provide a means for the determination of airborne concentrations of certain gases and vapors given in 29 CFR 1910.
5.3 A partial list of chemicals for which this practice is applicable is presented in Annex A1.
5.4 This practice also provides for the sampling of gaseous atmospheres to be used for process control or other purposes (2, 24-23).
SCOPE
1.1 This practice covers the detection and measurement of concentrations of toxic gases or vapors using detector tubes (1, 2).2 A list of some of the gases and vapors that can be detected by this practice, their 1994–95 TLV values recommended by the ACGIH, and their measurement ranges are provided in Annex A1. This list is given as a guide and should be considered neither absolute nor complete.
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.
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Designation: D4490 − 96 (Reapproved 2016)
Standard Practice for
Measuring the Concentration of Toxic Gases or Vapors
Using Detector Tubes
This standard is issued under the fixed designation D4490; 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 4. Summary of Practice (3)
4.1 Detector tubes may be used for either short-term sam-
1.1 This practice covers the detection and measurement of
concentrations of toxic gases or vapors using detector tubes (1, pling (grab sampling; 1 to 10 min typically) or long term
sampling (actively or passively; 1 to 8 h) of atmospheres
2). A list of some of the gases and vapors that can be detected
by this practice, their 1994–95 TLV values recommended by containing toxic gases or vapors.
4.1.1 Short-Term Sampling (Grab Sampling) (4-18)—A
the ACGIH, and their measurement ranges are provided in
Annex A1. This list is given as a guide and should be given volume of air is pulled through the tube by a mechanical
pump. If the substance for which the detector tube was
considered neither absolute nor complete.
designed is present, the indicator chemical in the tube will
1.2 This standard does not purport to address all of the
change color (stain). The concentration of the gas or vapor may
safety concerns, if any, associated with its use. It is the
be estimated by either (a) the length-of-stain compared to a
responsibility of the user of this standard to establish appro-
calibration chart, or (b) the intensity of the color change
priate safety, health, and environmental practices and deter-
compared to a set of standards.
mine the applicability of regulatory limitations prior to use.
4.1.2 Long-Term Active Sampling (Long-Term Tubes) (19-
1.3 This international standard was developed in accor-
22)—A sample is pulled through the detector tube at a slow,
dance with internationally recognized principles on standard-
constant flow rate by an electrical pump. The time-weighted
ization established in the Decision on Principles for the
average concentration of the gas or vapor is determined by
Development of International Standards, Guides and Recom-
correlating the time of sampling either with (a) the length-of-
mendations issued by the World Trade Organization Technical
stain read directly from the calibration curve imprinted on the
Barriers to Trade (TBT) Committee.
tube or (b) the intensity of the color change compared to a set
2. Referenced Documents
of standards.
4.1.3 Long-Term Passive Sampling (Diffusion or Dosimeter
2.1 ASTM Standards:
Tubes) (23)—The contaminant molecules move into the tube
D1356 Terminology Relating to Sampling and Analysis of
according to Fick’s First Law of Diffusion. The driving force is
Atmospheres
the concentration differential between the ambient air and the
2.2 Other Document:
inside of the tube. The time-weighted average concentration of
29 CFR 1910 Federal Occupational Safety and Health
the gas or vapor is determined by dividing the indication on the
Standard Title 29
tube by the number of hours sampled (1 to 10 h according to
3. Terminology
the manufacturers’ instructions).
3.1 For definitions of terms used in this method, refer to
4.2 Instructions are given for the calibration of the sampling
Terminology D1356.
pumps required in this practice.
4.3 Information on the correct use of the detector tubes is
This practice is under the jurisdiction of ASTM Committee D22 on Air Quality
presented.
and is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.
Current edition approved Oct. 1, 2016. Published October 2016. Originally
5. Significance and Use
approved in 1985. Last previous edition approved in 2011 as D4490 – 96 (2011).
DOI: 10.1520/D4490-96R16. 5.1 The Federal Occupational Safety and Health
The boldface numbers in parentheses refer to the list of references at the end of
Administration, in 29 CFR 1910, designates that certain gases
this practice.
and vapors must not be present in workplace atmospheres at
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
concentrations above specific values.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
5.2 This practice will provide a means for the determination
the ASTM website.
4 of airborne concentrations of certain gases and vapors given in
Code of Federal Regulations, Part 1910.1000 Subpart 2 and Part 1926.55
Subpart D. 29 CFR 1910.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4490 − 96 (2016)
5.3 A partial list of chemicals for which this practice is given in the manufacturers’ instruction manuals. The purpose
applicable is presented in Annex A1. of the pyrolyzer, as with reactor tubes, is to break down
difficult-to-detect compounds into other compounds more eas-
5.4 This practice also provides for the sampling of gaseous
ily detected. The breakdown in this case is caused by heat. The
atmospheres to be used for process control or other purposes
pyrolzyer is particularly useful for organic nitrogen
(2, 24-23).
compounds, one of the products of breakdown being nitrogen
6. Interferences (26, 27)
dioxide, which is easily monitored.
7.3.4 Remote Sampling Line—When the sampling point is
6.1 Some common interferences for the various tubes are
remote from the pump location, a length of nonreactive tubing
listed in the instruction sheets provided by the manufacturers.
can be attached to the pump with the detector tube attached to
7. Apparatus (28-31)
the other end of the tubing. This is useful for sampling in
inaccessible or dangerous places.
7.1 Detector Tube—A detector tube consists of a glass tube
7.3.5 Cooling Unit—The cooling unit consists of a length of
containing an inert granular material that has been impregnated
metal tubing through which the sampled gas is pulled. Because
with a chemical system which reacts with the gas or vapor of
of the high thermal conductivity of the metal tubing, the hot
interest. As a result of this reaction, the impregnated chemical
sampling gas is cooled sufficiently so that it will not destroy the
changes color. The granular material is held in place within the
indicator in the detector tube. The cooling unit must be placed
glass tube by porous plugs of a suitable inert material. The ends
upstream from the detector tube. Cooling units are particularly
of the glass tube are flame-sealed to protect the contents during
useful when sampling flue gases.
storage.
7.2 Pump (32):
8. Reagents
7.2.1 Short-Term Sampling—A mechanical, hand-operated,
8.1 The reagents used are specific for each tube, and, to
aspirating pump is used to draw the sample through the
detect a specific gas, may vary from manufacturer to manufac-
detector tube during the short-term sampling. Two types of
turer. The instruction sheets supplied by the manufacturers give
pumps are commercially available: piston-operated and
the principal chemical reaction(s) that occur(s) in the tube, thus
bellows-operated. The pumps have a capacity of 100 mL for a
showing the reagent that is used to react with the gas or vapor
full pump stroke. By varying the number of pump strokes, the
to produce the color change.
sample volume is controlled. Sampling pumps should be
maintained and calibration checked periodically according to
9. Sampling with Detector Tubes
the manufacturer’s instructions. The pumps shall be accurate to
9.1 General—Detector tubes made by one manufacturer
65 % of the volume stated.
must not be used with pumps made by a different manufacturer
7.2.2 Long-Term Sampling—Small electrical pumps having
(33). Each lot of detector tubes is calibrated at the manufac-
stable low flow rates (2 to 50 mL/min), are required for
turer’s plant, using their equipment. The pumps of other
long-term sampling (2 to 8 h). Flow rates to be used with each
manufacturers have different flow characteristics that cause
detector tube are given by the manufacturers. As with the
different lengths-of-stain, resulting in erroneous readings.
mechanical pumps, the electrical pumps must be maintained
and calibrated regularly. Maintenance and calibration are
9.2 Procedure (34)—The detector tube program should be
performed using the instructions supplied by the manufacturer
conducted under the supervision of a trained professional such
of the pump. The pump flow rate, and, therefore, the sampled
as a chemist or an industrial hygienist. Carefully follow the
volume, shall be accurate to 65 % of the stated flow rate. With
instruction sheet of the manufacturer for the proper use of each
this system either area or personal monitoring can be accom-
detector tube. In general, the instruction sheet will include the
plished.
following information.
9.2.1 Storage conditions.
7.3 Accessories—Several accessories are provided with de-
9.2.2 Shelf life.
tector tubes for special applications:
9.2.3 Chemical reaction and color change.
7.3.1 Reactor Tubes—These are tubes that are used in
9.2.4 Test procedure.
conjunction with detector tubes. Some gases and vapors,
9.2.5 Significant interferences.
because of their low reactivity, are not easily detected by
9.2.6 Temperature and humidity correction factors, if re-
detector tubes alone. The reactor tubes consist of very powerful
quired.
chemical reactants, which break down the unreactive com-
9.2.7 Correction for atmospheric pressure.
pound into other more readily detectable substances, which
9.2.8 Measurement range.
standard detector tubes can detect. Thus, the reactor tube is
placed upstream of the detector tube and the combination must
10. Accuracy of Detector Tubes
be used for certain compounds as a detector tube system.
7.3.2 Dryer Tubes—Water vapor interferes with the detec- 10.1 The Safety Equipment Institute (SEI) has a certifica-
tion of certain substances; therefore, dryer tubes are used tion program for certain detector tubes used in short-term
upstream of the detector tube in these cases to remove the sampling. This program is similar to the NIOSH program for
water vapor. evaluating and certifying detector tube performance (35, 36).
7.3.3 Pyrolyzer—A pyrolyzer is a hot wire instrument oper- Under this program, the tubes are required to meet an accuracy
ated by batteries. Instru
...
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: D4490 − 96 (Reapproved 2011) D4490 − 96 (Reapproved 2016)
Standard Practice for
Measuring the Concentration of Toxic Gases or Vapors
Using Detector Tubes
This standard is issued under the fixed designation D4490; 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 covers the detection and measurement of concentrations of toxic gases or vapors using detector tubes (1, 2).
A list of some of the gases and vapors that can be detected by this practice, their 1994–95 TLV values recommended by the ACGIH,
and their measurement ranges are provided in Annex A1. This list is given as a guide and should be considered neither absolute
nor complete.
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.
2. Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
2.2 Other Document:
29 CFR 1910 Federal Occupational Safety and Health Standard Title 29
3. Terminology
3.1 For definitions of terms used in this method, refer to Terminology D1356.
4. Summary of Practice (3)
4.1 Detector tubes may be used for either short-term sampling (grab sampling; 1 to 10 min typically) or long term sampling
(actively or passively; 1 to 8 h) of atmospheres containing toxic gases or vapors.
4.1.1 Short-Term Sampling (Grab Sampling) (4-18)—A given volume of air is pulled through the tube by a mechanical pump.
If the substance for which the detector tube was designed is present, the indicator chemical in the tube will change color (stain).
The concentration of the gas or vapor may be estimated by either (a) the length-of-stain compared to a calibration chart, or (b)
the intensity of the color change compared to a set of standards.
4.1.2 Long-Term Active Sampling (Long-Term Tubes) (19-22)—A sample is pulled through the detector tube at a slow, constant
flow rate by an electrical pump. The time-weighted average concentration of the gas or vapor is determined by correlating the time
of sampling either with (a) the length-of-stain read directly from the calibration curve imprinted on the tube or (b) the intensity
of the color change compared to a set of standards.
4.1.3 Long-Term Passive Sampling (Diffusion or Dosimeter Tubes) (23)—The contaminant molecules move into the tube
according to Fick’s First Law of Diffusion. The driving force is the concentration differential between the ambient air and the inside
of the tube. The time-weighted average concentration of the gas or vapor is determined by dividing the indication on the tube by
the number of hours sampled (1 to 10 h according to the manufacturers’ instructions).
4.2 Instructions are given for the calibration of the sampling pumps required in this practice.
4.3 Information on the correct use of the detector tubes is presented.
This practice is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.
Current edition approved Oct. 1, 2011Oct. 1, 2016. Published October 2011October 2016. Originally approved in 1985. Last previous edition approved in 20062011 as
ε1
D4490 – 96 (2006)(2011). . DOI: 10.1520/D4490-96R11.10.1520/D4490-96R16.
The boldface numbers in parentheses refer to the list of references at the end of this practice.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Code of Federal Regulations, Part 1910.1000 Subpart 2 and Part 1926.55 Subpart D.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4490 − 96 (2016)
5. Significance and Use
5.1 The Federal Occupational Safety and Health Administration, in 29 CFR 1910, designates that certain gases and vapors must
not be present in workplace atmospheres at concentrations above specific values.
5.2 This practice will provide a means for the determination of airborne concentrations of certain gases and vapors given in
29 CFR 1910.
5.3 A partial list of chemicals for which this practice is applicable is presented in Annex A1.
5.4 This practice also provides for the sampling of gaseous atmospheres to be used for process control or other purposes (2,
24-23).
6. Interferences (26, 27)
6.1 Some common interferences for the various tubes are listed in the instruction sheets provided by the manufacturers.
7. Apparatus (28-31)
7.1 Detector Tube—A detector tube consists of a glass tube containing an inert granular material that has been impregnated with
a chemical system which reacts with the gas or vapor of interest. As a result of this reaction, the impregnated chemical changes
color. The granular material is held in place within the glass tube by porous plugs of a suitable inert material. The ends of the glass
tube are flame-sealed to protect the contents during storage.
7.2 Pump (32):
7.2.1 Short-Term Sampling—A mechanical, hand-operated, aspirating pump is used to draw the sample through the detector tube
during the short-term sampling. Two types of pumps are commercially available: piston-operated and bellows-operated. The pumps
have a capacity of 100 mL for a full pump stroke. By varying the number of pump strokes, the sample volume is controlled.
Sampling pumps should be maintained and calibration checked periodically according to the manufacturer’s instructions. The
pumps shall be accurate to 65 % of the volume stated.
7.2.2 Long-Term Sampling—Small electrical pumps having stable low flow rates (2 to 50 mL/min), are required for long-term
sampling (2 to 8 h). Flow rates to be used with each detector tube are given by the manufacturers. As with the mechanical pumps,
the electrical pumps must be maintained and calibrated regularly. Maintenance and calibration are performed using the instructions
supplied by the manufacturer of the pump. The pump flow rate, and, therefore, the sampled volume, shall be accurate to 65 %
of the stated flow rate. With this system either area or personal monitoring can be accomplished.
7.3 Accessories—Several accessories are provided with detector tubes for special applications:
7.3.1 Reactor Tubes—These are tubes that are used in conjunction with detector tubes. Some gases and vapors, because of their
low reactivity, are not easily detected by detector tubes alone. The reactor tubes consist of very powerful chemical reactants, which
break down the unreactive compound into other more readily detectable substances, which standard detector tubes can detect.
Thus, the reactor tube is placed upstream of the detector tube and the combination must be used for certain compounds as a detector
tube system.
7.3.2 Dryer Tubes—Water vapor interferes with the detection of certain substances; therefore, dryer tubes are used upstream of
the detector tube in these cases to remove the water vapor.
7.3.3 Pyrolyzer—A pyrolyzer is a hot wire instrument operated by batteries. Instructions for its use and maintenance are given
in the manufacturers’ instruction manuals. The purpose of the pyrolyzer, as with reactor tubes, is to break down difficult-to-detect
compounds into other compounds more easily detected. The breakdown in this case is caused by heat. The pyrolzyer is particularly
useful for organic nitrogen compounds, one of the products of breakdown being nitrogen dioxide, which is easily monitored.
7.3.4 Remote Sampling Line—When the sampling point is remote from the pump location, a length of nonreactive tubing can
be attached to the pump with the detector tube attached to the other end of the tubing. This is useful for sampling in inaccessible
or dangerous places.
7.3.5 Cooling Unit—The cooling unit consists of a length of metal tubing through which the sampled gas is pulled. Because of
the high thermal conductivity of the metal tubing, the hot sampling gas is cooled sufficiently so that it will not destroy the indicator
in the detector tube. The cooling unit must be placed upstream from the detector tube. Cooling units are particularly useful when
sampling flue gases.
8. Reagents
8.1 The reagents used are specific for each tube, and, to detect a specific gas, may vary from manufacturer to manufacturer. The
instruction sheets supplied by the manufacturers give the principal chemical reaction(s) that occur(s) in the tube, thus showing the
reagent that is used to react with the gas or vapor to produce the color change.
9. Sampling with Detector Tubes
9.1 General—Detector tubes made by one manufacturer must not be used with pumps made by a different manufacturer (33).
Each lot of detector tubes is calibrated at the manufacturer’s plant, using their equipment. The pumps of other manufacturers have
different flow characteristics that cause different lengths-of-stainlengths-of-stain, resulting in erroneous readings.
D4490 − 96 (2016)
9.2 Procedure (34)—The detector tube program should be conducted under the supervision of a trained professional such as a
chemist or an industrial hygienist. Carefully follow the instruction sheet of the manufacturer for the proper use of each detector
tube. In general, the instruction sheet will include the following information.
9.2.1 Storage conditions.
9.2.2 Shelf life.
9.2.3 Chemical reaction and color change.
9.2.4 Test procedure.
9.2.5 Significant interferences.
9.2.6 Temperature and humidity correction factors, if required.
9.2.7 Correction for atmospheric pressure.
9.2.8 Measurement range.
10. Accuracy of Detector Tubes
10.1 The Safety Equipment Institute (SEI) has a certification program for certain detector tubes used in short-term sampling.
This program is similar to the NIOSH program for evaluating and certifying detector tube performance (35, 36). Under this
program, the tubes are required to meet an accuracy (95 % confidence level) of 625 % between one and five times the SEI test
concentration and 635 % at one half the test concentration. The SEI test concentration is chosen as the Threshold Limit Value as
defined by the American Conference of Governmental Industrial Hygienists for the test gas or vapor (37). The calculation of tube
accuracy is based on a set of statistical procedures (38) and provides an estimate of accuracy under actual use conditions. The SEI
Certified Equipment List should be consulted for the listing of approved units.
10.2 In general, the accuracy of any detector tube depends on the construction and chemistry of the tube along with the actual
composition of the test atmosphere and the conditions under which the tube is read. For gases and vapors not covered by the SEI
program, detector tubes may or may not meet the accuracy requirements of the previous paragraph (39, 40). There is also some
variation in accuracy between manufacturers’ tubes designed to detect a specific compound. Therefore the user should verify the
accuracy with the tube manufacturer or run his own tests to determine accuracy (41-43). It must be emphasized that a correct
estimate of accuracy can only be done by qualified operators and with careful attention to the generation and verification of test
gas or vapor concentrations (44).
10.3 Because the accuracy of a detector tube in sampling a specific compound depends on the cross-sensitivity of the tube to
other gases or vapors present in the test atmosphere, the manufacturer should be consulted for information on cross-sensitivity
effects for the specific chemistry employed in their tube. Quite frequently, several different indicating chemistries for a specific
compound are available. Proper choice of indicating chemistry can minimize the effect of a co-contaminant in the test atmosphere.
11. Keywords
11.1 air monitoring; detector tubes; dosimeter sampling; grab sampling; sampling and analysis; toxic gases and vapor;
workplace atmospheres
ANNEX
(Mandatory Information)
A1. SOME COMPOUNDS THAT CAN BE MEASURED BY DETECTOR TUBES
A1.1 The measurement ranges shown in Table A1.1 are not for a single tube. They are for the lowest and highest concentrations
listed in manufacturer’s brochures. Values are given in ppm(v) unless otherwise indicated.
D4490 − 96 (2016)
TABLE A1.1 Non-Exclusive List of Compounds Measurable by Detector Tubes
D4490 − 96 (2016)
TABLE A1.1 Continued
REFERENCES
(1) Air Sampling Instruments by the American Conference of Governmental Hygienists, 4th ed., 1972.
(2) American Industrial Hygiene Association: Direct Reading Colorimetric Indicator Tubes, 1st ed., 1976.
(3) Collings, A. J., “Performance“Performance Standard for Detector Tube Units Used to Monitor Gases and Vapors in Working Areas Standard for
Detector Tube Units Used to Monitor Gases and Vapors in Working Areas,” ,” Pure and Applied Chemistry, VolVol. 54, 1982, pp. 1763–1767, 1982.
–1767.
(4) Saltzman, B. E., Direct Reading Colorimetric Indicators, Air Sampling Instruments for Evaluation of Atmospheric Contaminants, fourth4th ed.,
American Conference of Governmental Industrial Hygienists, 1972.
(5) Ketcham, N. H., “Practical“Practical Experience with Routine Use of Field Indicators Experience with Routine Use of Field Indicators,” ,” American
Industrial Hygiene Association Journal, VolVol. 23, 1962 p. 127, 1962.
(6) Linch, A. L. and H. Pfaff, “Carbon“Carbon Monoxide—Evaluation of Exposure Potential by Personnel Monitor Surveys Monoxide—Evaluation of
Exposure Potential by Personnel Monitor Surveys,” ,” American Industrial Hygiene Association Journal, VolVol. 32, 1971, p. 745, 1971.
(7) Kitagawa, T: “The“The Rapid Measurement of Toxic Gases and Vapors Rapid Measurement of Toxic Gases and Vapors,” ,” Transactions of the 13th
International Congress on Occupational Health, New York, NY, 1960.
(8) Ringold, A., Goldsmith, J. R., Helwig, H. L., Finn, R., and F. Scheute, “Estimating“Estimating Recent Carbon Monoxide Exposures, A
...
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