Internal and external cleanliness of products

Product cleanliness testing is a very important element in the quality assessment of many components, especially those having contact with operating fluid. Such tests are carried out in a clean room of ISO 6 cleanliness class (according to ISO 14644).
The basic factors determining the purity of the tested object are: mass of insoluble impurities, mass of soluble impurities, amount of insoluble impurities of a certain size and type of contamination. In the case of insoluble (solid) impurities, it is possible to divide them according to their nature: metallic, non-metallic and fibers, as well as by chemical composition. In order to determine these properties, an appropriate extraction liquid is selected (it must be compatible with the component material) and method of pollutants extraction is selected: agitation, pressure washing, ultrasonic techniques, washing on functional test benches reflecting the working parameters of the test object. The choice of the extraction method depends on the characteristics of the tested object and on the specified properties: internal/external/overall purity.
Extracted pollutants are analyzed by the following methods:
  • gravimetric – the mass of contaminants
  • microscopic – the quantity and size of the contaminants
  • scanning electron microscopy (SEM)– the chemical composition of the impurities
  • infrared spectroscopy – the chemical composition of organic impurities



BOSMAL is the only laboratory in Poland accredited for testing of cleanliness according to ISO 16232, VDA 19.1 and DIN 8964-1


Testing norms

  • ISO 16232
  • DIN 8964-1

Testing norms from the industry and customers’ own norms

  • VDA 19.1, QV 11111, DBL 6515, DBL 6516, PV 3347, PV 3370, PV 3336, VW 01134, VW 01137, Volvo STD 107-0002, Scania STD 4189, GMW 16037, NW 22-10-202, SAE J1726, Continental TST N 002 02.22, Wabco JED 593, BWS 42001, Renault 34-07-012, Renault 34-07-025 and others.
Document No. Title/Description
ISO 16232 Road vehicles - Cleanliness of components and systems
VDA 19.1 VDA Volume 19 Part 1, Inspection of Technical Cleanliness - Particulate Contamination of Functionally Relevant Automotive Components
DIN 8964-1 Circuit components for refrigerating systems - Part 1: Testing