CWA 18305:2025

Challenge test for analysing presence of contaminants before / after samples decontamination CWA 18305:2025

Scope

This CEN Workshop Agreement establishes a challenge test (artificial contamination) process for plastic samples in form of granulates. Challenge tests can also be applied to plastics material samples, or other forms. The challenge test comprises a selection of contaminants, an artificial contamination process, completed by the verification of obtained contamination level. Quantitative analytical techniques to measure contamination before and after a recycling decontamination process are also included to define the performance level of the recycling decontamination process. As such, this challenge test is not applicable for chemical recycling processes. The decontamination process itself is not part of this challenge test.
The challenge test can be applied on polymers, and in a limited manner on metallic compounds. Application on metallic compounds was not investigated during SURPASS Horizon Europe project; adequacy with samples preparation process and protection of workers has therefore not been examined in this case.
The challenge test has been verified during SURPASS Horizon Projects for a selection of contaminants and a polyethylene (PE) polymer. As the process uses an extrusion process at polymer melt temperature in the range of 200°C to 220 °C, it is only adequate for contaminants that are not volatile at such temperatures.
NOTE For other application purposes, i.e. other categories of contaminated samples and/or other selection of contaminants, other polymers, the challenge test needs to be verified before implementation.