Cleaning operations in food factories produce airborne droplets that may carry microorganisms. Three laser-based systems were used to measure the sizes, fluxes and concentrations of airborne particles produced by a low pressure hose, a boot scrubber, a floor scrubber and a hand washer. The low pressure hose produced a particle flux of 144,000 cm(-2) s(-1) below 40 mum diameter and less than 900 CM-2 s-1 above 80 pm at 150 mm front the impact point of the water jet. The concentrations of particles greater than I pin diameter, due to the use of the hose, were up to 1.4 x 10(7) m(-3) around a room. The floor scrubber produced a particle concentration (>1 mum diameter) of 4.3 x 10(6) m(-3) at 300 mm from the scrubber. Almost all of the particles were below 5 mum. Particle concentrations around the room were up to 4.6 x 10(5) m(-3). The boot scrubber produced a particle flux of 750 particles cm(-2) s(-1) in the range 0-10 mum and less than 5 cm(-2) s(-1) greater than 100 mum. The highest concentration of particles (>1 mum) around the room was 6.0 x 10(5) m(-3). The hand washer was operated remotely. The highest particle concentration measured at the edge of the hand washer was 2.3 x 10(4) m(-3). The data can be used as part of a risk assessment or in numerical models used to predict particle dispersion and quantify risk. The data strongly indicates that the use of low pressure hoses should be discouraged during and immediately prior to production periods when foods may be exposed. (C) 2003 Elsevier Science Ltd. All rights reserved.