Occupational Risk Assessment Related to Ultrasonic Noise

In Poland ultrasonic noise is defined as noise containing high audible and low ultrasonic frequencies from 10 kHz to 40 kHz. It is estimated that more than 25,000 employees are exposed to this kind of noise emitted by technological ultrasonic devices (mainly by ultrasonic cleaners). Moreover, ultrasonic noise is included in the national list of factors harmful to health in the working environment. The existing admissible values of ultrasonic noise in the workplaces make it possible to perform occupational risk assessments. Ultrasonic noise measurements are carried out in accordance with a procedure. The procedure was developed on the basis of the results of studies carried out in the Central Institute for Labour Protection - National Research Institute. According to the procedure the scope of the measurements includes the determination of the equivalent sound pressure levels in the 1/3 octave bands with the center frequencies from 10 kHz to 40 kHz. The paper presents both the description of the procedure for measuring ultrasonic noise and the examples of the results of occupational risk assessments related to exposure to ultrasonic noise.