ISO 14644-13:2017 gives guidelines for cleaning to a specified degree on cleanroom surfaces, surfaces of equipment in a cleanroom and surfaces of materials in a cleanroom. Under consideration are all surfaces (external or internal) that are of interest. It provides guidance on the assessment of cleaning methods for achieving the required surface cleanliness by particle concentration (SCP) and surface cleanliness by chemical concentration (SCC) classes and which techniques should be considered to achieve these specified levels.The appropriateness of cleaning techniques will make reference to the cleanliness classes and associated test methods found in ISO 14644‑9 and ISO 14644‑10.The following matters of general guidance will be provided:- expected surface cleanliness levels;- suitability of cleaning methods;- compatibility of surfaces with the cleaning technique;- assessment of cleaning appropriateness.The following will be excluded from this document:- classification of cleaning methods;- product produced within a cleanroom;- specific surface-related cleaning methods;- detailed description of cleaning mechanisms, methods and procedures of various cleaning methods;- detailed material characteristics;- description of damage mechanisms by cleaning processes and time-dependent effects;- references to interactive bonding forces between contaminants and surfaces or generation processes that are usually time-dependent and process-dependent;- other characteristics of particles such as electrostatic charge, ionic charges, etc.;- chemical reactions between molecular contaminants and surfaces;- microbiological aspects of surface cleanliness;- radioactive aspects of contamination;- health and safety considerations;- environmental aspects such as waste disposal, emissions, etc.;- selection and use of statistical methods.