ISO 15181-2:2007

Overview

ISO 15181-2:2007 - Paints and varnishes - Determination of release rate of biocides from antifouling paints - Part 2 describes the analytical method and apparatus for measuring copper-ion concentration released from antifouling paints into artificial seawater, and for calculating the copper release rate (expressed in µg·cm−2·d−1) under the laboratory conditions defined in ISO 15181-1. The standard is intended for repeatable, quality-assurance testing and material selection rather than direct environmental exposure estimates.

Key topics and requirements

• Scope and purpose: Specifies analysis of copper-based biocides in extracts produced according to ISO 15181-1 and provides the final calculation for release rate.
• Analytical method: Primary technique is atomic absorption spectrometry (AAS) with autosampler or an alternative method that demonstrates a limit of quantitation (LOQ) for copper in artificial seawater of ≤ 10 µg/L (LOQ determined per ASTM D6442-06 Annex 2).
• Sample handling: Acidify extracts (0.10 mL concentrated nitric acid per 100 mL), agitate, filter (0.45 µm), store at 2–6 °C up to 14 days, and equilibrate to room temperature before analysis.
• Calibration and quality checks: Use five-point calibration in artificial seawater and recovery check standards at 10, 50 and 200 µg/L. Recovery acceptance: (100 ± 15)% at 10 µg/L and (100 ± 10)% at 50 and 200 µg/L.
• Calculation: Convert measured copper concentration in the extract to a release rate (µg·cm−2·d−1). When standard volume (1.5 L), area (200 cm2) and time are used, the standard provides a simplified expression (R ∝ C × 0.18 / t).
• Quantitative limits: Practical measurement range when used with ISO 15181-1 is approximately 1.8 to 500 µg·cm−2·d−1; lower release rates require more sensitive analytical LOQs.

Applications and users

• Who uses it: Paint manufacturers, independent testing laboratories, R&D teams, quality control personnel, certification bodies and product formulators working with antifouling coatings.
• Practical uses:
  • Routine quality-control testing of copper-based antifouling paints.
  • Comparative material selection and product development.
  • Laboratory-based release-rate characterization for product specifications.
• Limitations: Results typically overestimate in-service environmental release rates (often by an order of magnitude); not suitable alone for regulatory environmental-risk assessments or direct environmental loading estimates without applying appropriate correction factors.

Related standards

• ISO 15181-1:2007 - General method for extraction of biocides (required companion).
• Other parts of ISO 15181 (Parts 3–5) - methods for different biocides.
• ISO 3696 - Water for analytical laboratory use.
• ASTM D6442-06 - LOQ determination for copper in substitute ocean water.

Keywords: ISO 15181-2:2007, antifouling paints, copper-ion concentration, release rate, artificial seawater, atomic absorption spectrometer, biocide release rate, ISO 15181-1.