Foreword

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This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology, Subcommittee SC 2, Marine environment protection.

A list of all parts in the ISO 21716 series can be found on the ISO website.

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Introduction

Anti-fouling paints that contain biocides are widely used to prevent the fouling of ship hulls by marine organisms. Effective anti-fouling technologies are critical for maintaining the fuel consumption efficiency of ships and for minimizing possible translocation of aquatic species through maritime trade. The evaluation of anti-fouling paints is generally undertaken by adopting a tiered approach whereby paint manufacturers use a battery of laboratory, raft, patch tests and full vessel trials. Raft, patch tests and full vessel trials are generally conducted over extended periods of time and are predominantly relied upon for the prediction of coating performance when used commercially on in-service ships.

The results of raft, patch test and full vessel trials (field testing) can be used as part of the regulatory process for pesticidal or biocidal products in certain countries in order to demonstrate the efficacy of an anti-fouling paint. Laboratory testing alone is recognized as being unable to predict in-service performance or efficacy. For example, guidance published by the European Chemical Agency (ECHA)^[ 1 ^] on the assessment and evaluation of the efficacy of anti-fouling products states clearly that laboratory testing of individual anti-fouling paints is not performed as it is not considered to be a realistic evaluation of the product. Field testing, which permits anti-fouling products to be tested under similar operating conditions and stresses as those encountered when the anti-fouling products are in service, is routinely undertaken instead.^[ 1 ^]

Although laboratory tests are unable to reliably predict in-service coating performance, they have merit in the screening of experimental coatings for further evaluation during the research and development process.

Reproducible objective data obtained by following standardized screening methods, independent of the test location or the season, can be a useful tool to support the selection of anti-fouling paints for higher tier testing, e.g. raft or ship tests. The ISO 21716 series provides a compilation and description of in vitro bioassay methods intended to aid the process of screening anti-fouling paints prior to higher tier raft or ship tests. Toxicological screening methods included in each part of the ISO 21716 series can be used for purposes such as early decision-making in research and product development, rapid feedback on potential toxicological concerns, or for the preliminary assessment of anti-fouling paints. For instance, the ISO 21716 series provides information on methods that can be used to screen anti-fouling paints in order to determine whether to continue development of either an experimental paint or a product, or both, that contains a particular ingredient, or to determine whether to take on the cost of performing the remaining tiers within a complete tiered-testing strategy.

The ISO 21716 series provides screening bioassays related to certain common genera of fouling organisms, namely barnacles, mussels and algae. These screening tests are relatively simple and rapid laboratory tests that can be performed to provide an indication of the toxicity of a painted surface towards selected test organisms. The screening tests described in each part of the ISO 21716 series can be used as part of a tiered approach to predict the ability of an anti-fouling paint to prevent fouling on ships. Alternatively, these screening tests can be used to prevent the translocation of invasive marine species by progressively involving subsequent semi-field (e.g. raft panels) and field testing (e.g. ship trials). On their own, the screening tests described in each part of the ISO 21716 series do not reliably predict the ability of an anti-fouling paint to prevent fouling on ships or the translocation of invasive marine species.

The ISO 21716 series is not intended to provide a list of validated tests for testing the efficacy of anti-fouling paints; this can be covered by applicable legal regulations in each country or region. It is also not intended to be used for predicting the ability of a fouling control paint to prevent fouling on ships or to prevent the translocation of invasive marine species.

Algae are typical marine sessile organisms regarded as harmful fouling organisms because of their impact on fuel consumption and the potential for translocation of non-indigenous species if they become attached to ship hulls.

The test method specified in this document utilizes algae to assess their colour change in the presence of treated panels. The brown macroalga is used because they are considered a major ship-fouling organism and its colour change is easily measured compared to other algae. More information is provided in Annex C.

1 Scope

This document specifies the laboratory test method for screening anti-fouling paints in a flow-through system using algae as the test organism. It is intended to be used in conjunction with ISO 21716-1 , which specifies the general requirements of the test methods described in the other parts of the ISO 21716 series . The purpose of the test specified in this document is to determine the difference in colour of algae on painted test panels compared with algae on inert non-toxic control panels under the test conditions.

2 Normative references

3 Terms and definitions

4 Test procedure

5 Materials and apparatus

6 Preparation of test organism and test seawater

6.1 General

6.2 Preparation of test organism

6.3 Preparation of test seawater

7 Preparation of test/control panel

7.1 General

7.2 Preparation of test panels

7.3 Affixing algae on the substrates

8 Algae viability test

8.1 General

8.2 Requirements

8.3 Operation of the algae viability test

9 Bioassay

9.1 General

9.2 Operation

10 Colour space

10.1 General

10.2 Calculation of the average value of the parameters of colour space

10.3 Data treatment and interpretation of the results

11 Test report

Bibliography