Security measures
Contenido
Casi todos los países industrializados han establecido regulaciones de seguridad específicas para el trabajo en techos, como el uso de sistemas convencionales de protección contra caídas, que incluyen sistemas personales de detención de caídas, sistemas de barandas y redes de seguridad.
La Agencia Europea para la Seguridad y la Salud en el Trabajo define las situaciones de riesgo (prevención de caídas, materiales que caen, tipos de techos), las precauciones, la capacitación necesaria y la legislación europea que se centra en el trabajo en techos.[24] Las directrices europeas establecen estándares mínimos para la salud y la seguridad y se transponen a la legislación de todos los Estados miembros.
En los Estados Unidos, los estándares de la OSHA exigen a los empleadores que tengan disponibles varios medios de prevención de caídas, a fin de garantizar la seguridad de los trabajadores. En la construcción esto abarca a los trabajadores que estén expuestos a caídas de 6 pies de altura o más cuando trabajen por encima de los niveles más bajos.[25][26]Algunos estados dejan la regulación del trabajo en techos a discreción de las jurisdicciones a nivel de ciudad, condado o municipio. Emplear a contratistas sin licencia para proyectos con un valor superior a un cierto umbral puede llevar a severas multas o incluso a penas de cárcel. En algunos estados, como en Oklahoma, los techadores deben cumplir con las directrices sobre seguros y licencias para el trabajo en techos. Los techadores también deben mostrar el número de licencia en sus materiales de publicidad.
Las normas en Canadá son muy similares a las de los Estados Unidos y la autoridad para regular depende de la provincia en la que esté ubicada la empresa.
En el 2009, en Japón, se enmendaron las directrices y regulaciones de seguridad y salud ocupacionales como respuesta a las altas tasas de caídas en la construcción. En ese mismo país, en el 2013, el cumplimiento era bajo y se identificó la necesidad de continuar investigando y de tener medidas correctivas de prevención que garantizaran la protección contra las caídas de alturas.[27].
El Reino Unido no tiene legislación que exija a los techadores tener una licencia para desempeñarse en el oficio, aunque algunos techadores pertenecen a organizaciones gremiales reconocidas.[28].
Personal fall arrest systems
The purpose of personal fall arrest systems is to prevent falls by preventing the worker from making contact with the surface below them. This system consists of a mooring line with a deceleration device, along with a harness and an anchor.
In addition to these mandatory components of fall arrest systems, there are also specific fall distances associated with the operation of the system. Specifically, there is a total fall distance that fall arrest systems must allow in order to help the worker avoid contact with the ground or other surface below. The total fall distance consists of the free fall distance, deceleration distance, hitch D-ring offset, back D-ring height, and safety margin. In addition to fall distance requirements for each system component, the system anchorage must support a minimum of 5,000 pounds per worker.[29].
Requirements of OSHA regulations. The free fall distance, that is, the distance the worker falls before the arrest system begins to operate and slow the fall, must be 6 feet or less, without contact with any level below. Deceleration, the length the harness must stretch to stop the fall, should not be more than 3.5 feet.[30] The travel of the attachment D-ring, the distance the harness stretches and how far the D-ring itself moves until it meets the worker's full weight during a fall, is generally considered to be 1 foot, depending on the equipment design and harness manufacturer. Regarding back D-ring height, the distance between the D-ring and the soles of the worker's shoes, employers often use 5 feet as the standard height, with the assumption that the worker will be 6 feet tall; However, because D-ring height variability can affect system safety, the back D-ring height should be calculated based on the actual height of the worker. The margin of safety, the additional distance needed to ensure sufficient clearance between the worker and the surface below after a fall occurs, is generally considered a minimum of 2 feet.[31].
Fall restraint system
A fall restraint system is a type of fall protection system that is intended to prevent workers from reaching the unprotected sides or edges of a work area where a fall may occur. This system is useful when a worker could lose balance or begin to slip near an unprotected edge. In this case, the fall restraint system will prevent the worker from continuing to go towards an unprotected side or edge and will prevent a serious fall. While OSHA's standards for protecting against falls in construction do not explicitly define or mention fall restraint systems,[32][33] OSHA allows them, as specified in an OSHA interpretation letter updated in 2004.[34]OSHA does not have specific requirements for fall restraint systems, but recommends that they be capable of supporting 3,000 pounds or at least twice the maximum intended force. as necessary to save the worker from a fall to a lower surface.[35] There are no OSHA specifications for the distance the restraint system must allow from the edge to prevent a worker from having a fall, and while it is a likely very dangerous practice, OSHA's interpretation letter states that, as long as the restraint system prevents the employee from falling from the edge, the employee can be restrained "within inches of the edge."[34].
railing systems
Guardrail systems serve as an alternative to fall arrest and restraint systems, using permanent or temporary guardrails around the perimeter of the roof and any openings in the roofs. OSHA requires the height of the handrail to be 39 to 45 inches above the work surface. Rails must be installed between the top of the railing and the walking or working surface when there is no guard wall at least 21 inches high. Guardrail systems must be capable of sustaining 200 pounds of force, in any outward or downward direction, applied within 2 inches of the top edge of the rail.[36][37].
Safety net systems
Safety net systems use a tested net next to (or below) the edge of the walking or working surface to stop workers who may have fallen from the ceiling. Safety nets should be installed as close as practically possible below the working surface and should extend outward from the most peripheral projection of the working surface, as follows:[38].
Prior to initial use, safety nets must be tested by dropping a 400-pound sandbag or a certification record must be submitted.[39].
Warning line systems
Warning line systems consist of ropes, cables, or chains that are marked every 6 feet with high-visibility materials, and must be supported so that they are 34 to 39 inches above the walking or working surface.[40]Warning line systems are passive systems that allow a perimeter to be established around the work area so that workers are aware of dangerous edges. Warning lines are only permitted on roofs with a slight pitch (a slope of 4 inches or less of vertical rise per 12 inches of horizontal length (4:12)).[41] In the context of fall protection in roof construction, warning line systems may only be used in combination with a guardrail system, a safety net system, a personal fall arrest system, or a safety monitoring system. The warning line system must be installed around all sides of the work area on the ceiling.[4].
Security monitoring systems
Safety monitoring systems employ workers to monitor the safety of their co-workers on rooftops. Those in charge of monitoring must be competent to recognize fall hazards. The safety monitor is tasked with ensuring the safety of other workers on the roof and must have the ability to verbally warn an employee who is in an unsafe situation.[42].