ISO 8623:2015

Overview

ISO 8623:2015 - Tall-oil fatty acids for paints and varnishes: Test methods and characteristic values specifies laboratory test methods and provides typical characteristic values for distilled tall-oil fatty acids used in paints and varnishes. Rather than mandating requirements, this second edition supplies analytical procedures and reference characteristic values to support quality control, procurement, and formulation decisions in coatings and allied industries.

Key topics and technical requirements

The standard focuses on analytical testing and reporting of properties relevant to paint and varnish applications. Key technical topics include:

• Characteristic values (typical/reference values) for distilled tall-oil fatty acids:

  • Density: 0.900–0.910 g/cm3 at 20 °C; 0.898–0.908 g/cm3 at 23 °C (ISO 2811)
  • Colour: max. 5 (Gardner scale, ISO 4630)
  • Acid value: ≥ 192 mg KOH/g (ISO 2114)
  • Saponification value: ≥ 193 mg KOH/g (ISO 3681)
  • Iodine value: ≥ 125 g I2/100 g (ISO 3961)
  • Unsaponifiable matter: max. 5% (mass fraction) - determined by the diethyl ether method (Annex A, normative)
  • Rosin acid content: max. 2.5% (mass fraction) - determined by the butanol–sulphuric esterification/titration method (Annex B, normative)

• Test methods included:

  • Annex A: detailed procedure for determination of unsaponifiable matter (diethyl ether extraction, drying, titration).
  • Annex B: determination of rosin acids (esterification with butanol/sulphuric reagent and titration; results expressed as abietic acid).

• Normative references cited for instrumentation and ancillary methods, e.g., ISO 2114, ISO 2811, ISO 3681, ISO 3961, ISO 4630 and ISO 3696 for water quality.

Applications and users

ISO 8623:2015 is practical for:

• Paint, varnish and coating formulators assessing raw tall-oil fatty acid quality.
• Quality control and analytical laboratories performing acceptance testing on incoming tall-oil fatty acids.
• Procurement/specification engineers and suppliers who need consistent test methods and characteristic values for contract specifications.
• R&D teams evaluating feedstock suitability for binder modification, drying characteristics, or additive compatibility.

Using ISO 8623:2015 helps ensure reproducible test results, consistent supplier comparison, and informed decisions about tall-oil fatty acid suitability in coatings formulations.

Related standards

Relevant standards referenced in ISO 8623:2015 include:

• ISO 2114 (acid value), ISO 2811 (density), ISO 3681 (saponification value), ISO 3696 (laboratory water), ISO 3961 (iodine value), ISO 4630 (Gardner colour), ISO 383 (glassware joints).

Keywords: ISO 8623:2015, tall-oil fatty acids, paints and varnishes, test methods, characteristic values, unsaponifiable matter, rosin acid, acid value, saponification value.