Microplastics in water finally have their own standard
Microplastics in drinking water finally have one standard: particles from 1 µm to 5 mm are counted and classified by infrared and Raman microscopy. The result is a particle count in size classes, not a single mass value.
- Until now every laboratory tested microplastics its own way — a different sieve, a different size range, a different criterion for calling a particle plastic.
- The standard covers drinking water and water with low suspended solids, and counts particles between one micrometre and five millimetres.
- The polymer type is identified by spectroscopic methods: infrared microscopy and Raman microscopy.
- The whole path of the sample is described — collection, filtration, removal of organic matter, transfer onto the measurement filter and how to count.
- Background contamination is handled separately, because the biggest source of error is often the laboratory itself: clothing, air, plastic equipment.
- The result is reported as a particle count in size classes broken down by polymer, so test reports have to accommodate that.
- A part based on chromatography after pyrolysis is in preparation — it will give the mass of plastic instead of a particle count.
Source: ISO