Gradingʻ

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# Heavy Equipment and Utility Vehicles Used for Grading and Excavating Tasks (cont.) ## Wet Methods (cont.) Water must be applied at flow rates sufficient to minimize the release of visible dust. Too much water can create mud slurry that can cause hazards. Too little water will not effectively control dust emissions. ## Operator Isolation When operators rely on enclosed cabs for protection against silica dust, the cab must: • Be well-sealed and well-ventilated using positive pressure. - Have door jambs, window grooves, power line entries and other joints that work properly and are tightly sealed. - Have heating and air conditioning, so that operators can keep windows and doors closed. • Use an intake air filter with a minimum MERV- 16 rating (at least 95 percent efficient in the 0.3-10.0 μm range). • Be kept free from settled dust by regular cleaning and maintenance to prevent dust from become airborne inside the enclosure. Modern heavy equipment often comes equipped with enclosed, filtered cabs that meet the requirements of the silica standard in Table 1. Retrofit equipment is available for older equipment. ## Respiratory Protection When properly used, an enclosed cab or wet methods can effectively control airborne silica dust. Therefore, Table 1 in the silica standard for construction does not require the use of respirators when wet methods are used for dust suppression, or for the operator when operating heavy equipment or utility vehicles from within an enclosed cab. ## Additional Information For more information, visit www.osha.gov/silica and see the OSHA Fact Sheet on the Crystalline Silica Rule for Construction, and the Small Entity Compliance Guide for the Respirable Crystalline Silica Standard for Construction. OSHA can provide compliance assistance through a variety of programs, including technical assistance about effective safety and health programs, workplace consultations, and training and education. OSHA's On-Site Consultation Progra…

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# OPERATING MACHINE ## Grading Operation Operate the boom, arm, and the bucket in such a way so that the bucket teeth move horizontally, constantly keeping them perpendicular to the ground at the grading operation. IMPORTANT: Do not pull or push dirt with the bucket when traveling. Excess force will be applied on each part, and the machine may be damaged. 1. Operate arm roll-in function while slowly raising the boom. Once the arm moves past the vertical position, slowly lower the boom to allow the bucket to maintain a smooth surface. 2. Arm roll-out operation is performed in the reverse way of step 1. 3. Do the slope finishing work in the same procedure as described in steps 1 and 2. MLBA-05-011 5-21

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OSHA FactSheet CONTROL SILICA DUST Breathe Easier CONTROL OF SILICA DUST IN CONSTRUCTION # Heavy Equipment and Utility Vehicles Used for Grading and Excavating Tasks Using heavy equipment and utility vehicles for earthmoving tasks such as grading and excavating does not in most cases generate hazardous levels of respirable crystalline silica dust. However, in dry conditions hazardous exposures can occur. This fact sheet describes methods to minimize the amount of airborne dust when using heavy equipment or utility vehicles for earthmoving tasks such as grading and excavating soil, as listed in Table 1 of the Respirable Crystalline Silica Standard for Construction, 29 CFR 1926.1153. A separate fact sheet covers dust controls for heavy equipment used for abrading, or fracturing silica-containing materials during demolition activities. Engineering Control Methods: Enclosed cab (when only the operator is exposed) OR water sprays and/or dust surfactants (a dust suppressant) The application of water and/or dust suppressants can help to reduce exposure to dust when operating heavy equipment or utility vehicles for tasks such as grading and excavating. If the equipment operator is the only worker engaged in the task, the employer can choose to apply water and/or dust suppressants to minimize dust emissions or can require the operator to stay within an enclosed cab. However, if there are other workers engaged in the task, then water and/or dust suppressants must be applied as needed to minimize their exposure to airborne dust. ## Wet Methods Wet methods for heavy equipment and utility vehicle operators include the use of any method that will suppress dust emissions and be compatible to the job task. These include using: • Tank trucks equipped with hoses and nozzles that spray water or other dust suppressants over large areas to wet the materials disturbed during earthmoving tasks, including haul roads and job sites in general. - A worker who assists the operator …

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# GROUND WORK # MOVIMIENTO DE TIERRAS Grading. Before construction Conformando. Antes que empiece starts, more grading is done to la obra, se hace más nivelación ensure the ground is level. pare asegurar que el terreno esté nivelado. PESO - Residential Construction Safety 54 PESO - Seguridad en la Construcción Residencial