What is ISO 21256 ‑ 2 about?
ISO 21256 discusses cleaning applications by fine bubble technology. ISO 21256 ‑ 2 outlines a test method for the removal of machine oil stain from a non-corrosive metal surface using fine bubble water. A test is provided to show the comparative cleaning advantage of adding fine bubbles to the water.
The main cleaning solvent fluids used in these industries are solvent-based (e.g., hydrocarbon detergent liquids, bromine-containing detergents, and alkali detergents), despite it being well known that such detergents can cause environmental pollution such as ozone layer depletion, water pollution, etc.