Gutter Protection
A dry walk to their garden shelter Enjoying a private garden can be a year-round event at this house in Vancouver, Washington. Even on a typically damp Northwestern day, owners Del and Eugene Blizard can walk 30 feet to a peak-roofed shelter and hardly a drop of rain will strike them. Projecting more than 2 feet past teh gutter, the extenders could have created a drip line at their outer edges. Long wedge-shaped shims, mounted to the tops of the extenders, tilt tha acrylic sheet so it drains back toward the gutter. Portland landscape architect John Herbst, jr., designed the remodel.
Three laboratory standards are used to measure the performance of protective clothing materials against liquid pesticides. These three standards were compared in a previous study to determine the suitability of the test methods to screen protective clothing materials against liquid pesticides. The results of that study, reported in Part I, showed that fabric performance was affected by the test methods used. For this study, the three test methods are modified so they can be used to measure the performance of fabrics based on different exposure conditions. The gutter method is modified to allow increased contact time between the pesticide formulation and the fabric. An additional volume is added to the pipette method to allow the test method to measure the performance of materials under high and low exposure levels. The atomizer method is modified to allow application of higher volumes and/or concentrations of the liquid pesticide. The results are used to determine the level of exposure(s) that the test methods represent while screening materials against liquid pesticides. Based on the results, the gutter method with a low angle of incline and rate of application as well as the pipette method with a higher volume are suitable for measuring performance for high exposure levels. The atomizer method and the pipette method with lower volume are more suitable for lower exposure levels.Appropriate personal protective equipment (PPE) is used by the agricultural industry to enhance the health and safety of individuals who handle and spray pesticides. PPE recommendations on pesticide labels are typically based on factors such as the task, the toxicity of the formulation, and the engineering controls used to apply the pesticide. For example, the PPE requirements for mixing and loading pesticides are more stringent than those for applying field strength mixtures. The PPE requirements for spraying class I (most toxic) pesticides are more stringent than those for classes III and IV. In addition to the toxicity of the formulation, the level of exposure is taken into consideration. The PPE requirements are lower when engineering controls (such as spraying from an enclosed tractor cab) are used when applying pesticides.Three national/international standard methods (gutter, pipette, and atomizer) have been proposed and used to measure the performance of PPE materials against penetration of liquid pesticides. In an earlier study we conducted to compare these three laboratory test methods [6], our results showed that evaluations of fabric performance were affected by the test method used. This was due to the differences in the approach taken to develop the test methods. The gutter method, EN 368 [4], was developed to measure fabric performance against splashes or accidental liquid spillage of pure liquids. To simulate these conditions, 10 mL of the formulation was dispensed in 10-seconds at a 45° incline, and the gravimetric method was used to measure repellency and penetration. On the other hand, the atomizer method, BBA-3-3/2 German guideline [2], was designed to measure the performance of textile materials against atomized liquid pesticide. To simulate field conditions, an atomized liquid that represented spraying with a tractor-mounted boom sprayer was used to contaminate the fabric, and penetration through the materials was determined by measuring the active ingredient of the formulation. The pipette method was developed as an accelerated test method to measure the performance of textile materials against a known volume of liquid pesticides (concentrate and field strength). For that method, the active ingredient was also analyzed to determine the performance of materials against liquid pesticides.