ASTM D6492-99(2022)

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: D6492 − 99 (Reapproved 2022)
Standard Practice for
Detection of Hexavalent Chromium On Zinc and Zinc/
Aluminum Alloy Coated Steel
This standard is issued under the fixed designation D6492; 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 spot test will vary.Abrading the surface with emery paper will
improve the likelihood of reliable detection. This technique is
1.1 This practice can be used to detect the presence of
not recommended for acrylic resin containing passivation
hexavalent chromium on galvanized and zinc/aluminum alloy
treatments.
coated steel surfaces. Hexavalent chromium-bearing treat-
ments (passivates) can be applied to coated steels to prevent 1.5 The values stated in SI units are to be regarded as the
storage stain. While passivated 55 % aluminum-zinc alloy standard. The values given in parentheses are for information
coated steel is commonly painted, passivated galvanized steel only.
is not. Chrome passivation may interfere with the successful
1.6 This standard does not purport to address all of the
pretreatment of galvanized steel, as well as contaminate
safety concerns, if any, associated with its use. It is the
cleaning and pretreatment baths on a coil coating line.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.2 The amount of hexavalent chromium that will cause the
mine the applicability of regulatory limitations prior to use.
indicator to produce a discernible pink color is in the range of
1.7 This international standard was developed in accor-
0.5 parts per million dissolved in the indicator solution. It is
dance with internationally recognized principles on standard-
possible that a coated steel surface that produces a negative
ization established in the Decision on Principles for the
result does have chromium on the surface. If a material that
Development of International Standards, Guides and Recom-
yieldsanegativeresultissuspectedofhavingchromiumonthe
mendations issued by the World Trade Organization Technical
surface, instrumental methods should be used. Chrome depos-
Barriers to Trade (TBT) Committee.
its of 1 mg/ft can be easily missed by analytical instruments
such as the scanning electron microscope with energy disper-
2. Referenced Documents
sive x-ray analysis (EDXA) capability. Auger electron spec-
troscopy (AES) or electron spectroscopy for chemical analysis 2.1 ASTM Standards:
D2092 Guide for Preparation of Zinc-Coated (Galvanized)
(ESCA) can identify chemical species present in the levels
required for adequate detection. Stripping the metallic coating Steel Surfaces for Painting (Withdrawn 2008)
D5723 Practice for Determination of Chromium Treatment
and analyzing for chrome by atomic absorption or inductively
coupled plasma can also give reliable results in detecting the Weight on Metal Substrates by X-Ray Fluorescence
presence of chrome.
3. Apparatus
1.3 This practice is designed to be a qualitative means of
3.1 The following materials will be required to perform the
screening chrome passivated coils from those which are not
stripping procedure:
chrome passivated.
3.1.1 Dark colored or Brown Polyethylene Wash Bottle,
1.4 Some chromium-free passivates are being used com-
(500 mL) or brown glass dropper bottle.
mercially. Although these products will test negative for
3.1.2 TestSpecimens, which may be cut panels or coil stock.
hexavalent chromium, they may interfere with cleaning and
pretreating. Chromium bearing passivates that contain film 4. Reagents
forming constituents such as acrylic resins are also being
4.1 Thefollowingchemicalreagentsarerequiredtoperform
commercially applied. The reaction of these products to the
this procedure:
1 2
This practice is under the jurisdiction of ASTM Committee D01 on Paint and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
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