Two Stage Decontamination of Agricultural Equipment Using Power Washing Followed by Disinfectant Treatments

Foreign agricultural pests can become problematic to the environment, economy, animal, plant, and human health if widely transported on contaminated equipment or vehicles. Two equipment decontamination studies were conducted using a mobile power washer and disinfectant treatments. The first study factors were: steel and fabric surfaces, power washing conditions, disinfectants, and disinfectant adjuvants. The second study factors were: relative humidity conditions, disinfectant type, disinfectant additive, and number of repeat disinfectant applications. Efficacy for the power washing and disinfectant treatments was based on log10 reduction of Bacillus subtilis spores attached to the two surface types. Power washing increased log10 reduction of spores by 3 to 4 log, when washing was followed by disinfectant treatments. The optimal decontamination treatment in the first study was power washing for 30 seconds at a distance of 10 cm, using a commercial chlorine dioxide formulation (Electro-Biocide) with Reign (1%) that resulted in a 4.7 log10 reduction of B. subtilis spores on steel washers. In the second study the optimal treatment was power washing for 10 seconds at a nozzle distance of 20 cm with a commercial disinfectant (Easy Decon DF-200) mixed with 20% glycerol resulting in a 5.1 log10 reduction of B. subtilis spores on wool fabric samples.