hazards of working in a building trench

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TENSIN MASSACHUSETTS DEPARTMENT OF LABOR STANDARDS # Trench Hazard Alert MASSsafety Works! Workplace Safety is No Accident Every year, workers are killed or seriously injured conducting work in trenches, including utility repair, utility inspections, and construction. Trenches are recognized by OSHA as one of the most hazardous construction work conditions, with a fatality rate more than double that for construction work overall. ## Requirements for Trench Work • Protect workers from soil cave-ins in all trenches 5' or deeper, and in shallower trenches where a cave-in hazard exists. Do this by supporting the walls with shoring, shielding workers with trench boxes, or sloping the walls back wide enough, in accordance with the OSHA Excavation Standard. • Provide ladders to workers in trenches 4' or deeper. • Underground utilities must be identified and supported. Call Dig Safe at 1-(888) 344-7233. • Ensure that workers wear high visibility clothing when exposed to vehicle traffic, and use appropriate work zone signage and traffic channeling set-ups. . Spoils must be kept back a minimum of 2' from the trench edge. Keep equipment and heavy material as far back from the trench edge as possible. • Stabilize undermined adjacent structures. • Protect employees from water accumulation by pumping out ground or utility water, and preventing drainage or other water from entering the trench. • Do not allow employees to work under suspended or raised loads or materials. • Conduct pre-job planning and inspections of trench worksites. A competent person must inspect each trench worksite, including the soil protective system, prior to the start of work, and again if there is a hazard-increasing change in conditions such as a rainstorm. Unsafe trenches are dangerous! Trenches more than 20 feet in depth must be designed by a registered professional engineer. ## Workers in trenches face other significant hazards in addition to cave-in of the soil walls, including: . …

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# Case Study: Carbon Monoxide Exposure (cont.) ## Item 1e 1910.1200(h)(1) (cont.) # Excavation Work: Unpredictable but Preventable Cave-in Hazards Excavation/trenching work is one of the most dangerous types of construction activities, and workers can be seriously or fatally injured within minutes of being caught in a collapse. Cave-ins pose the greatest risk and predominantly occur in work related to excavation, utilities, and underground infrastructure projects and are much more likely than other excavation-related accidents to result in worker fatalities. Other potential hazards include falls, falling loads, hazardous atmospheres, and struck-by incidents involving mobile equipment. One cubic yard of soil can weigh as much as a car. Some factors that can contribute to trench collapses include soil type, weather conditions, the width and depth of the trench, failing to use adequate protective measures, and lack of inspections by a competent person. Employees often take risks entering excavations without proper cave-in protection due to tight project deadlines, a lack of understanding of the hazards, or the belief that a task will "only take a minute." These five key safety tips will help keep workers safe: . Ensure there's a safe way to enter and exit. • Ensure trenches have cave-in protection. . Look for standing water and test if atmospheric hazards are or may be present. . Keep materials away from the edge of the trench. • Never enter a trench unless it has been properly inspected by a competent person. Due to the high risk, OSHA has targeted enforcement initiatives and awareness campaigns aimed at reducing trench fatalities. Under the Trenching and Excavation National Directive. Compliance Safety and Health Officers (CSHOS) across the U.S. are authorized to initiate inspections whenever they observe an open trench or excavation, regardless of whether a violation is readily observed. O Trenching & Excavation Special Emphasis Program OSHA Tren…

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# Tennessee OSHA's Special Emphasis Program on Trenching & Excavation Because trenching and excavation collapse is deadly and often involves multiple victims, Tennessee OSHA has established a special emphasis program to focus attention and resources on these hazards. It is impossible to predict when an excavation or trench will collapse. The sudden collapse of the walls makes escape almost impossible. The only way to prevent collapse is to slope or shore the walls or install a trench shield and follow the TOSHA trenching and excavation standards contained in 29 CFR 1926 Subpart P. Under this special emphasis program, all TOSHA compliance and consultative services personnel will be on the lookout for trenching or excavation work sites. Personal observation, reports of imminent danger, fatality/catastrophe reports, safety and health agency referrals, employee complaints, and media reports are also used to locate trenching and excavation work. Each occurrence is handled with an appropriate intervention by TOSHA. ## Hazards on the Excavation Site Excavation workers are exposed to many hazards, but the chief hazard is cave-in. TOSHA requires that all employees exposed to potential cave-ins be protected by sloping or benching the sides of the excavation, shoring the sides of the excavation, or placing a shield between the sides and the work area. In addition to cave-in hazards, workers must also be protected from adjacent utility lines, exposure to vehicular traffic, falling loads, hazardous atmospheres, and fall hazards. Utility lines such as gas, electrical, sewer, and water must be located and supported prior to placing employees in an excavation. Employees working in, or near, roadways must wear high visibility vests. Workers are not to work beneath suspended loads, and walkways crossing excavations must be equipped with guardrails. Precautions, including atmospheric testing and emergency rescue procedures and equipment, must be taken when workers enter excavat…

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CCOHS CCHST Canadian Centre for Occupational Health and Safety Centre canadien d'hygiène et de sécurité au travail Health and Safety Programs # Trenching and Excavation ## On this page What is meant by a trench and an excavation? What are the hazards associated with trenching and excavation? What is meant by soil types? What should occur before beginning an excavation? What factors determine what is the appropriate protective system to use? What are the different types of protective systems used to protect against cave-ins? What should NOT be done during an excavation? What can be included in a trenching and excavation inspection checklist? ## What is meant by a trench and an excavation? Generally speaking, an excavation is a hole in the ground as the result of removing material. A trench is an excavation in which the depth exceeds (is bigger than) the width. ## What are the hazards associated with trenching and excavation? Working in trenches and excavations is hazardous to both the workers who work inside them, and to workers on the surface. The hazards include: - Cave-ins or collapses that can trap or crush workers. - Equipment or excavated soil falling on workers (e.g., equipment is operated or soil and debris is stored too close to the excavation). - Falling into the trench or excavation. - Flooding or water accumulation. - Exposure to a hazardous atmosphere (e.g., gas, vapour, dust, biological contaminants, or lack of oxygen). Trenching and Excavation CCOHS