Generation and dispersion of droplets from cleaning equipment used in the chilled food industry Original Research Article

The low pressure hose produced a particle flux of 144,000 cm−2 s−1 below 40 μm diameter and less than 900 cm−2 s−1 above 80 μm at 150 mm from the impact point of the water jet. The concentrations of particles greater than 1 μm diameter, due to the use of the hose, were up to 1.4×107 m−3 around a room. The floor scrubber produced a particle concentration (>1 μm diameter) of 4.3×106 m−3 at 300 mm from the scrubber. Almost all of the particles were below 5 μm. Particle concentrations around the room were up to 4.6×105 m−3. The boot scrubber produced a particle flux of 750 particles cm−2 s−1 in the range 0–10 μm and less than 5 cm−2 s−1 greater than 100 μm. The highest concentration of particles (>1 μm) around the room was 6.0×105 m−3. The hand washer was operated remotely. The highest particle concentration measured at the edge of the hand washer was 2.3×104 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.