Evaluation of the exposure risk to ultrasound emitted by ultrasonic cleaner machines: A case study

Ultrasonic washing machines are now increasingly widespread for both industrial and domestic use, and their inappropriate use can be hazardous to health. This paper presents a study on the ultrasonic emissions of these types of washing machines and their evaluation in compliance with current regulations. Since no threshold values or exposure limits for ultrasound are defined in the Italian and European legislation, some of the most stringent criteria, valid in other European and non-European countries, have been adopted to define a set of rules for the evaluation. Since 2015 a new methodology has been developed in the context of the collaboration between Eni S.p.A. (an Italian multinational oil and gas company) and CNR (Italian National Research Council) to assess the risk related to ultrasound emission. As a case study, an analysis of various ultrasonic washing machines of different sizes and power will be presented.