ASTM D3724-01(2019)

Standard Specification for Synthetic Brown Iron Oxide Pigment

ABSTRACT
This specification establishes the properties and requirements for the pigments commercially known as synthetic pure brown iron oxides and its blends, suitable for use in paints and coatings. The pigment, which shall be soft, dry, and finely pulverized, may be manufactured by either of the following methods: precipitation of iron salts; calcination of precipitated iron oxides; blends of synthetic red, yellow, and black iron oxides; and blends of synthetic red, yellow, and black iron oxides plus the addition of carbon black. Specimens shall be suitably sampled and tested, and shall adhere to specified requirements as to total iron oxide, ferrous iron, carbon black, moisture and other volatile matter, organic coloring matter, total sulfates, coarse particles (total residue retained on No. 325 sieve), and water-soluble matter.
SCOPE
1.1 This specification covers the pigments commercially known as synthetic pure brown iron oxides and blends. These pigments are suitable for use in paints and coatings. Methods of manufacture are:  
1.1.1 Precipitation of iron salts.  
1.1.2 Calcination of precipitated iron oxides.  
1.1.3 Blends of synthetic red, yellow, and black iron oxides.  
1.1.4 Blends of synthetic red, yellow, and black iron oxides plus the addition of carbon black to a maximum of 5.0 %. Small amounts of carbon black are added to obtain tinting colors not obtainable when synthetic brown iron oxide or carbon black are used singly.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 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: 30-Sep-2019
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.31 - Pigment Specifications

Relations

• Replaces: ASTM D3724-01(2012) - Standard Specification for Synthetic Brown Iron Oxide Pigment
• Effective Date: 01-Oct-2019
• Refers: ASTM E350-23 - Standard Test Methods for Chemical Analysis of Carbon Steel, Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and Wrought Iron
• Effective Date: 15-Nov-2023
• Refers: ASTM D1208-96(2019) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Jun-2019
• Refers: ASTM D3872-05(2019) - Standard Test Method for Ferrous Iron in Iron Oxides
• Effective Date: 01-May-2019
• Refers: ASTM E351-18 - Standard Test Methods for Chemical Analysis of Cast Iron—All Types
• Effective Date: 01-Jul-2018
• Refers: ASTM E351-13 - Standard Test Methods for Chemical Analysis of Cast Iron—All Types
• Effective Date: 01-Feb-2013
• Refers: ASTM D1208-96(2012) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Nov-2012
• Refers: ASTM D280-01(2012) - Standard Test Methods for Hygroscopic Moisture (and Other Matter Volatile Under the Test Conditions) in Pigments
• Effective Date: 01-Nov-2012
• Refers: ASTM D3872-05(2011) - Standard Test Method for Ferrous Iron in Iron Oxides
• Effective Date: 01-Jun-2011
• Refers: ASTM D50-90(2011) - Standard Test Methods for Chemical Analysis of Yellow, Orange, Red, and Brown Pigments Containing Iron and Manganese
• Effective Date: 01-Jun-2011
• Refers: ASTM D387-00(2008) - Standard Test Method for Color and Strength of Chromatic Pigments with a Mechanical Muller
• Effective Date: 01-Feb-2008
• Refers: ASTM D185-07 - Standard Test Methods for Coarse Particles in Pigments
• Effective Date: 01-Jul-2007
• Refers: ASTM D1208-96(2007) - Standard Test Methods for Common Properties of Certain Pigments
• Effective Date: 01-Jun-2007
• Refers: ASTM D280-01(2007) - Standard Test Methods for Hygroscopic Moisture (and Other Matter Volatile Under the Test Conditions) in Pigments
• Effective Date: 01-Feb-2007
• Refers: ASTM E351-93(2006) - Standard Test Methods for Chemical Analysis of Cast Iron-All Types
• Effective Date: 01-Jun-2006

Overview

ASTM D3724-01(2019), titled Standard Specification for Synthetic Brown Iron Oxide Pigment, provides detailed requirements and guidelines for pigments commercially known as synthetic pure brown iron oxides and their blends. Issued by ASTM International, this specification defines the essential characteristics that brown iron oxide pigments must exhibit for use in paints and coatings industries. The document covers both the chemical and physical properties of the pigment, ensuring consistency, performance, and safety in end-use applications.

Developed in line with internationally recognized principles, including the World Trade Organization’s guidelines, ASTM D3724 supports global trade and harmonization of quality standards in pigments for coatings.

Key Topics

• Scope and Application

  • Defines synthetic brown iron oxide pigments and their suitable use in paints and coatings.
  • Details acceptable manufacturing methods, including:
    • Precipitation of iron salts
    • Calcination of precipitated oxides
    • Blends of synthetic red, yellow, and black iron oxides, with or without carbon black

• Material Requirements

  • Pigment must be soft, dry, finely pulverized, and meet strict limits for:
    • Total iron oxide (Fe2O3)
    • Ferrous iron (FeO)
    • Carbon black (maximum 5%)
    • Moisture and volatile matter (maximum 1%)
    • Total sulfates and water-soluble matter
    • Absence of organic coloring matter
    • Control of coarse particles (residue retained on No. 325 sieve)

• Testing and Quality Assurance

  • Mandates random sampling of pigment lots for quality control.
  • Specifies referenced ASTM test methods for measuring composition and properties, such as:
    • Color and tint strength
    • Particle size
    • Chemical analysis
    • Moisture content

• International Standardization

  • Developed according to WTO TBT Committee decision, strengthening cross-border acceptance of pigment quality.

Applications

The requirements outlined in ASTM D3724-01(2019) ensure synthetic brown iron oxide pigments deliver reliable, uniform performance in:

• Paints and Architectural Coatings
  • Used in decorative, protective, and industrial paints for walls, exteriors, and infrastructure
• Industrial Finishes
  • Applied in wood stains, powder coatings, and specialty industrial products where coloration and durability are essential
• Concrete and Building Materials
  • Enhances the color and aesthetic appeal of concrete, masonry, tiles, and bricks
• Blending and Tinting
  • Allows manufacturers to create a wide range of brown shades and customized colors unavailable from single pigments alone

By enforcing strict pigment specifications, this standard helps manufacturers, specifiers, and end-users maintain consistent color quality and process efficiency across applications.

Related Standards

For thorough quality control and compliance, ASTM D3724-01(2019) refers to several other ASTM standards and testing methods, including:

• ASTM D50 - Chemical analysis of yellow, orange, red, and brown pigments
• ASTM D185 - Testing for coarse particles in pigments
• ASTM D280 - Measurement of moisture and volatile matter in pigments
• ASTM D387 - Assessing color and strength of chromatic pigments with a mechanical muller
• ASTM D1208 - Methods for testing properties of various pigments
• ASTM D3872 - Test method for measuring ferrous iron in iron oxides
• ASTM E350/E351 - Chemical analysis methods for carbon steel, iron, and cast iron

Compliance with ASTM D3724, alongside these related standards, supports the production and utilization of high-quality brown iron oxide pigments for global coatings and construction industries.

Keywords: synthetic brown iron oxide, pigment specification, ASTM D3724, pigment testing, coatings industry, paint pigments, pigment quality, international 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: D3724 −01 (Reapproved 2019)
Standard Specification for
Synthetic Brown Iron Oxide Pigment
This standard is issued under the fixed designation D3724; 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 D1208 Test Methods for Common Properties of Certain
Pigments
1.1 This specification covers the pigments commercially
D3872 Test Method for Ferrous Iron in Iron Oxides
known as synthetic pure brown iron oxides and blends. These
E350 Test Methods for Chemical Analysis of Carbon Steel,
pigments are suitable for use in paints and coatings. Methods
Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, and
of manufacture are:
Wrought Iron
1.1.1 Precipitation of iron salts.
E351 Test Methods for ChemicalAnalysis of Cast Iron—All
1.1.2 Calcination of precipitated iron oxides.
Types
1.1.3 Blends of synthetic red, yellow, and black iron oxides.
1.1.4 Blends of synthetic red, yellow, and black iron oxides
3. Composition and Properties
plus the addition of carbon black to a maximum of 5.0 %.
3.1 The pigment shall be a manufactured iron oxide or a
Small amounts of carbon black are added to obtain tinting
blend. It shall be a soft dry finely pulverized pigment and shall
colors not obtainable when synthetic brown iron oxide or
conform to the following requirements:
carbon black are used singly.
FeO 0to10%
1.2 The values stated in SI units are to be regarded as the
Fe O 83 to 98 %
2 3
Carbon black, max, % 5.0 %
standard. The values given in parentheses are for information
Moisture and other volatile matter, max, % 1.0 %
only.
Organic coloring matter none
Total sulfates expressed as SO , max, % 2.0 %
1.3 This international standard was developed in accor-
Coarse particles (total residue retained on No. 1.0 %
dance with internationally recognized principles on standard-
325 (45-µm) mesh sieve, max, %
ization established in the Decision on Principles for the
Matter soluble in water, max, % 0.5 %
Development of International Standards, Guides and Recom-
3.2 Inasmuchassyntheticbrownironoxidesareavailablein
mendations issued by the World Trade Organization Technical
awiderangeofshades.Themasscolorandcharacterofthetint
Barriers to Trade (TBT) Committee.
and the tinting strength formed by a mixture with a white
pigment shall be within mutually agreed upon limits of a
2. Referenced Documents
standard acceptable to both the purchaser and the seller when
2.1 ASTM Standards:
tested by Test Method D387.
D50 Test Methods for ChemicalAnalysis ofYellow, Orange,
4. Sampling
Red, and Brown Pigments Containing Iron and Manga-
nese
4.1 Two samples shall be taken at random from different
D185 Test Methods for Coarse Particles in Pigments
packages from each lot, batch, day’s pack, or other unit of
D280 Test Methods for Hygroscopic Moisture (and Other
production in a shipment. When no markings distinguishing
Matter Volatile Under the Test Conditions) in Pigments
between units of production appear, samples shall be taken
D387 Test Met
...