ISO 21716-1:2020

Overview

ISO 21716-1:2020 - Ships and marine technology - Bioassay methods for screening anti-fouling paints - Part 1: General requirements defines the general requirements and common specifications for preparing and aging test panels coated with anti-fouling paints for laboratory bioassay screening. The standard applies to anti-fouling paints that work by chemical or biological means (biocide-containing paints) and is intended to be used together with the other parts of the ISO 21716 series that specify organism-specific bioassays (e.g., barnacles, mussels, algae). ISO 21716-1:2020 is not applicable to biocide-free foul-release coatings or to ballast-water control methods.

Key topics and technical requirements

• Test panel workflow: selecting substrate material, applying paint according to manufacturer instructions, aging panels in seawater, inspecting and pre-treating panels prior to bioassay.
• Substrate selection: panels must be non-conductive and suitable for seawater immersion; test surface size is specified in the relevant series part.
• Application and film thickness: paints are prepared per ISO 1513 and applied to produce a dry film thickness representative of typical commercial use; thickness measurement follows ISO 2808.
• Aging methods: panels are aged by exposure to natural or artificial seawater (dynamic, static, or combined). Dynamic or combined aging is recommended to more quickly approximate in-service surface conditions. Aging durations of 21 days or longer may be used, with control of temperature, pH and salinity.
• Inspection and pre-treatment: post-aging visual inspection for defects (cracks, delamination, insufficient thickness). Any biofilm should be gently removed without damaging the coating; damaged panels must be rejected.
• Control versus test groups: replicate control panels (inert or uncoated) are used alongside aged test panels to confirm reproducibility.
• Limitations: laboratory screening provides reproducible, rapid data for R&D and screening but does not reliably predict in-service performance - field (raft/ship) trials remain necessary for efficacy claims.

Practical applications and users

ISO 21716-1:2020 is primarily used by:

• Paint manufacturers and R&D teams for early screening of experimental anti-fouling formulations
• Independent laboratories conducting standardized bioassay screening
• Marine coating formulators selecting candidates for higher-tier field trials
• Regulatory and conformity-assessment bodies seeking consistent laboratory data to support testing programs
• Shipyards and asset owners evaluating product selection prior to raft or ship-scale testing

Typical uses include ranking experimental coatings, preliminary toxicological screening, and shortlisting products for raft or full-vessel trials as part of a tiered testing strategy.

Related standards

• ISO 21716 series (organism-specific parts, e.g., Part 2: Barnacles; Part 3: Mussels)
• ISO 1513 - Paints and varnishes: examination and preparation of test samples
• ISO 2808 - Paints and varnishes: determination of film thickness

Keywords: ISO 21716-1:2020, anti-fouling paints, bioassay methods, panel aging, laboratory screening, ships and marine technology, test panels, dry film thickness.