ASTM F3078-15(2023)
(Test Method)Standard Test Method for Identification and Quantification of Lead in Paint and Similar Coating Materials using Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF)
Standard Test Method for Identification and Quantification of Lead in Paint and Similar Coating Materials using Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF)
SIGNIFICANCE AND USE
5.1 This test method provides for analysis of Pb in applied paint using measurement times on the order of several minutes. It can be used to determine whether the sample of applied paint has an areal mass of Pb either substantially less than a specification limit, and therefore does not exceed it, or substantially above the specified limit, and therefore exceeds it.
5.2 If the value obtained with this test method falls close to a specification limit, a more precise test method may be required to positively determine whether Pb content does or does not exceed the specified limit.
SCOPE
1.1 This test method describes an energy dispersive X-ray fluorescence (EDXRF) procedure for determining the areal mass of Pb in mass per unit area in paint and similar coatings on common substrates of toys and consumer products, such as plastic, wood, steel, aluminum, zinc alloys or fabric.
1.2 This test method is applicable for homogeneous, single layer paint or similar coatings. The method does not apply to metallic coatings.
1.3 This test method is applicable for a range of Pb mass per unit area from 0.36 μg/cm2 to approximately 10 μg/cm2 for Pb in paint and similar coatings applied on common substrates. The lower limit of this test method is between 0.36 and 0.75 μg/cm2 depending on the nature of the substrate. Based on the results obtained during the interlaboratory study (ASTM Report F40-1004), it is estimated that the applicable range of this method can be extended up to 50 μg/cm2.
1.4 The values stated in SI units are to be regarded as standard. Values given in parentheses are for information only.
1.5 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.
1.6 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
Relations
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: F3078 − 15 (Reapproved 2023)
Standard Test Method for
Identification and Quantification of Lead in Paint and Similar
Coating Materials using Energy Dispersive X-ray
Fluorescence Spectrometry (EDXRF)
This standard is issued under the fixed designation F3078; 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. Referenced Documents
2.1 ASTM Standards:
1.1 This test method describes an energy dispersive X-ray
fluorescence (EDXRF) procedure for determining the areal D16 Terminology for Paint, Related Coatings, Materials, and
Applications
mass of Pb in mass per unit area in paint and similar coatings
on common substrates of toys and consumer products, such as D883 Terminology Relating to Plastics
D1005 Test Method for Measurement of Dry-Film Thick-
plastic, wood, steel, aluminum, zinc alloys or fabric.
ness of Organic Coatings Using Micrometers
1.2 This test method is applicable for homogeneous, single
D6132 Test Method for Nondestructive Measurement of Dry
layer paint or similar coatings. The method does not apply to
Film Thickness of Applied Organic Coatings Using an
metallic coatings.
Ultrasonic Coating Thickness Gage
1.3 This test method is applicable for a range of Pb mass per
D6299 Practice for Applying Statistical Quality Assurance
2 2
unit area from 0.36 μg/cm to approximately 10 μg/cm for Pb
and Control Charting Techniques to Evaluate Analytical
in paint and similar coatings applied on common substrates.
Measurement System Performance
The lower limit of this test method is between 0.36 and 0.75
D7091 Practice for Nondestructive Measurement of Dry
μg/cm depending on the nature of the substrate. Based on the
Film Thickness of Nonmagnetic Coatings Applied to
results obtained during the interlaboratory study (ASTM Re-
Ferrous Metals and Nonmagnetic, Nonconductive Coat-
port F40-1004), it is estimated that the applicable range of this
ings Applied to Non-Ferrous Metals
method can be extended up to 50 μg/cm .
E135 Terminology Relating to Analytical Chemistry for
Metals, Ores, and Related Materials
1.4 The values stated in SI units are to be regarded as
E177 Practice for Use of the Terms Precision and Bias in
standard. Values given in parentheses are for information only.
ASTM Test Methods
1.5 This standard does not purport to address all of the
E691 Practice for Conducting an Interlaboratory Study to
safety concerns, if any, associated with its use. It is the
Determine the Precision of a Test Method
responsibility of the user of this standard to establish appro-
C693 Test Method for Density of Glass by Buoyancy
priate safety, health, and environmental practices and deter-
F2576 Terminology Relating to Declarable Substances in
mine the applicability of regulatory limitations prior to use.
Materials
1.6 This international standard was developed in accor-
2.2 Other Standards:
dance with internationally recognized principles on standard-
Consumer Products Safety Improvement Act of 2008 (CP-
ization established in the Decision on Principles for the
SIA), Public Law 110-314, August 14, 2008
Development of International Standards, Guides and Recom-
SSPC-PA2 Paint Application Standard No. 2, Measurement
mendations issued by the World Trade Organization Technical
of Dry Coating Thickness with Magnetic Gauges
Barriers to Trade (TBT) Committee.
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
This test method is under the jurisdiction of ASTM Committee F40 on Standards volume information, refer to the standard’s Document Summary page on
Declarable Substances in Materials and is the direct responsibility of Subcommittee the ASTM website.
F40.01 on Test Methods. Full text is available on the Consumer Products Safety Commission website:
Current edition approved Oct. 1, 2023. Published November 2023. Originally http://www.cpsc.gov//PageFiles/113865/cpsia.pdf.
approved in 2015. Last previous edition approved in 2015 as F3078 – 15. DOI: Available from Society for Protective Coatings (SSPC), 40 24th St., 6th Floor,
10.1520/F3078-15R23. Pittsburgh, PA 15222, http://www.sspc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3078 − 15 (2023)
NIST Special Publication 829 Use of NIST Standard Refer- 3.1.8 Rayleigh scatter, n—the elastic scattering of an X-ray
ence Materials for Decisions on Performance of Analyti- photon through its interaction with the bound electrons of an
cal Chemical Methods and Laboratories atom; this process is also referred to as coherent scatter.
3.1.8.1 Discussion—The measured count rate of Compton
and Rayleigh scattered radiation varies depending upon speci-
3. Terminology men composition. The measured count rate of the Compton
and Rayleigh scattered radiation or the ratio of Compton/
3.1 Definitions:
Rayleigh scatter may be used to compensate for matrix effects
3.1.1 Definitions of terms applying to X-ray fluorescence
specific to XRF analysis.
(XRF) spectrometry, plastics and declarable substances appear
3.1.9 screening, n—screening is an analytical test procedure
in Terminology E135, Terminology D883 and Terminology
to determine the presence or absence of a substance (such as
F2576, respectively. Definitions of terms applying to Paint
Pb) or compound in the representative part or section of a
appear in Terminology D16.
product, relative to the value or values accepted as the criterion
3.1.2 areal mass (or mass per unit area), n—mass of
for such decision.
substance (element) contained in a unit area of surface over
3.1.9.1 Discussion—The value or values accepted as the
which substance (element) is uniformly spread.
criterion for decision shall be within the applicable range and
3.1.2.1 Discussion—This way of expressing the mass of a
above the limit of detection of the method. If the screening test
substance is typical and useful when material is present in a
produces values that are not conclusive, then additional analy-
form of thin layer rather than bulk volume. The term is used not
sis or other follow-up actions may be necessary to make a final
only in XRF analysis but also in a variety of coating industry
presence/absence decision.
applications. Areal mass is related to mass fraction through the
thickness and density of the layer (see X1 for an example).
3.1.10 thin sample, n—applied paints and similar coatings
represent a type of sample which is markedly different from a
3.1.3 Compton scatter, n—the inelastic scattering of an
bulk sample of infinite thickness. The absorption and enhance-
X-ray photon through its interaction with the bound electrons
ment phenomena typical of XRF analysis of bulk materials are
of an atom; this process is also referred to as incoherent scatter.
minimized by the fact that layer of paint is “thin”. A layer of
3.1.4 empirical method, n—a method for calibration of
paint is considered “thin” for XRF purposes if it fulfills the
X-ray fluorescence response of an analyzer using well
following criterion :
characterized, representative samples (calibrants).
m·μ # 0.1 (1)
3.1.5 fundamental parameters (FP) method, n—a method
for calibration of X-ray fluorescence response of an analyzer,
where:
which includes the correction of matrix effects based on the
μ = a mass absorption coefficient of the sample for exciting
theory describing the physical processes of the interactions of
radiation and characteristic X radiation of excited ele-
X rays with matter. 2
ment in cm /g, and
3.1.6 homogeneous coating, n—the coatings such as paints m = mass per unit area of the sample (areal mass) in g/cm .
or similar types are considered homogeneous for purposes of
3.2 Acronyms:
XRF analysis when their elemental composition is independent
3.2.1 EDXRF—energy dispersive X-ray fluorescence
with respect to the measured location on the specimen and
3.2.2 FP—fundamental parameters
among separate specimens obtained from the same material.
3.1.7 infinite thickness, n—the thickness of a specimen
4. Summary of Test Method
above which no measurable count rate increase is observed for
4.1 An EDXRF analyzer that has been calibrated using
any analyte is referred to as ‘infinite thickness’.
either a fundamental parameters approach or an empirical
3.1.7.1 Discussion—Bulk materials with a matrix of low
approach is used to directly measure the areal mass of Pb in
atomic number elements, such as polymers or wood, exhibit
paint applied on any of the common substrates described in 1.1
relatively low X-ray absorption. This leads to a requirement
by placing the painted surface of the object to be tested over the
that for the best quantitative analysis the specimens must be
measuring aperture (window) of the analyzer and initiating the
thick, generally in excess of several millimeters, depending on
measurement. Alternatively, when using a handheld XRF
the X-ray energies to be measured and the actual composition
analyzer, its measuring aperture (window) should be placed
of the matrix. In general, more accurate and precise results can
flush against the painted area of the object. The analyzer can be
be obtained when the reference materials and the unknown
calibrated either by the manufacturer or by the user.
samples are of infinite thickness or if thicknesses of the
4.2 The test sample for this method should be a single,
reference materials and unknown samples are at least within
10 % relative of each other. Typical substrates on which paint homogenous layer of dry, solid paint or similar coating applied
over substrate material.
is applied may often be considered to be of infinite thickness
for the purpose of XRF analysis.
Rhodes J.R., Stout J.A., Schindler S.S. and Piorek S., “Portable X-ray Survey
Meters for In-Situ Trace Element Monitoring of Air Particulates,” in Toxic Materials
Available from National Institute of Standards and Technology (NIST), 100 in The Atmosphere: Sampling and Analysis, ASTM STP 786, ASTM International,
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. 1981, pp. 70–82.
F3078 − 15 (2023)
4.3 The test sample should cover the measuring aperture of 6.3 Substrate Interferences—Elements in the substrate may
an analyzer. interfere with determination of Pb in a layer of paint. For
example, if both substrate and paint contain Pb, the composite
NOTE 1—Increased quantitative error may result if the coated sample
Pb signal will include contributions from both sources and
area does not cover the measuring aperture of the analyzer. Correction
effectively may result in a significant positive bias of Pb mass
schemes may be available to adjust the measurements of such samples.
These schemes have not been evaluated for this method. Refer to the per unit area. For example, a plastic substrate containing 100
analyzers manufacturer’s instructions for guidance.
mg/kg of Pb may produce apparent areal Pb concentration of
30 μg/cm , even if paint on such substrate does not contain Pb.
4.4 The test sample is irradiated by an X-ray source, and the
resulting characteristic X rays of Pb and other elements present
7. Apparatus
in the sample are measured. A value of the Pb mass per unit
area of the paint sample is calculated and compared to the
7.1 EDXRF Spectrometer, designed for X-ray fluorescence
specification limit against which the sample is being evaluated.
analysis of materials with energy dispersive selection of
radiation. Any EDXRF spectrometer can be used if its design
5. Significance and Use
incorporates the following features.
7.1.1 A means of repeatable sample presentation for
5.1 This test method provides for analysis of Pb in applied
analysis—For hand-held spectrometers this is usually a small,
paint using measurement times on the order of several minutes.
flat plane with round, oval or rectangular aperture that comes
It can be used to determine whether the sample of applied paint
into direct contact with the sample and through which X rays
has an areal mass of Pb either substantially less than a
can reach the sample under test. Laboratory embodiments of
specification limit, and therefore does not exceed it, or sub-
analyzer design may have specimen holders and a specimen
stantially above the specified limit, and therefore exceeds it.
chamber.
5.2 If the value obtained with this test method falls close to
7.1.2 Source of X-ray Excitation, typically an X-ray tube,
a specification limit, a more precise test method may be
capable of exciting the Pb L -M (Lβ ) line (secondary line: Pb
2 4 1
required to positively determine whether Pb content does or
L -M (Lα )).
3 4,5 1,2
does not exceed the specified limit.
7.1.3 X-ray Detector, with energy resolution sufficient to
resolve the recommended Pb L -M (Lβ ) line from X-ray
2 4 1
6. Interferences
lines of other elements present in sample. An energy resolution
6.1 Spectral Interferences—Spectral interferences in XRF of better than 250 eV at the energy of Mn K-L (Kα) has been
2,3
found suitable for the purpose of Pb analysis.
analysis manifest themselves as overlaps of spectral peaks
representing lines of different X-ray energies. These overlaps
7.1.4 Signal conditioning and data handling electronics,
are the result of limited energy resolution of detectors. For
that include the functions of X-ray counting and peak/spectrum
example, the As Kα peak overlaps completely the Pb Lα peak.
processing.
Interactions of photons with the detector and limitations of
7.1.5 Data Processing Software, for calculating elemental
associated electronics give rise to additional peaks in a
composition of sample from measured X-ray intensities using
spectrum known as escape peaks and sum peaks. For example,
one of calibration methods.
high content of iron in a paint or substrate may produce a sum
7.2 The following spectrometer features and accessories are
peak that will overlap with the Pb Lβ line. Fundamental
optional.
Parameters equations require that the measured net count rates
7.2.1 Beam Filters—Used to make the excitation more
be free from line overlap effects. Some empirical approaches
selective and to reduce background count rates.
incorporate line overlap corrections in their equations. The
7.2.2 Secondary Targets—Used to produce semi-
software used for spectrum treatment must compensate for line
mon
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