Safety guards must never be removed when a tool is being used. For example, portable circular saws must be equipped with guards. An upper guard must cover the entire blade of the saw. A retractable lower guard must cover the teeth of the saw, except when it makes contact with the work material.

Always wear appropriate PPE to protect you from the specific hazards presented by power tools, such as dust exposure and projectiles. PPE such as goggles, dust mask, gloves, hard hat, and safety boots should be worn where appropriate.

Safety guards must never be removed when a tool is being used.

Never carry a tool by the cord or hose. Never yank the cord or the hose to disconnect it from the receptacle. Keep cords and hoses away from heat, oil, and sharp edges. Disconnect tools when not using them, before servicing and cleaning them, and when changing accessories such as blades, bits, and cutters.

4 Major Hazards: Scaffold Safety

1. Falls. Falls are attributed to the lack of guardrails, improper installation of guardrails and failure to use personal fall arrest systems when required.
2. Scaffold collapse.
3. Struck by falling materials.
4. Electrocution.

“Scaffolding work is fraught with risk and can be extremely dangerous if it isn’t carried out properly. People should be able to walk along a pavement without having to worry about a piece of scaffold slipping from the hands of an overhead worker.

The adverse impacts of hazards, in particular natural hazards, often cannot be prevented fully, but their scale or severity can be substantially lessened by various strategies and actions.

To prevent cave-ins:

• SLOPE or bench trench walls.
• SHORE trench walls with supports, or.
• SHIELD trench walls with trench boxes.

Cave-ins pose the greatest risk in trenching and excavation operations, 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 incidents involving mobile equipment.

There are two basic methods of protecting workers against cave-ins:

• Sloping.
• Temporary protective structures (e.g., shoring, trench boxes, pre-fabricated systems, hydraulic systems, engineering systems, etc.)

Trenches 5 feet (1.5 meters) deep or greater require a protective system unless the excavation is made entirely in stable rock. If less than 5 feet deep, a competent person may determine that a protective system is not required.

More videos on YouTube Some common excavation works associated with trench-related accidents involve sewer, water, communication, and power line constructions. OSHA data reveal that most trench-related accidents occur below 10 feet.

Type C soil cannot be benched.

How Deep Can a Trench Be Without Shoring? Trenches with a depth of 5 feet (1.5 meters) or greater need a protective system unless the entire excavation is in stable rock. If there is anything less than 5 feet, it is up to a competent person’s discretion to determine if there is a need for a protective system.

– A gas line hit can lead to an explosion. – A broken water line can fill a trench in seconds. – Contact with buried power cables can kill. Safety Tip: Always your local utility locating service such as 811 before you dig, and get the utilities marked.

Trench collapse risks can be minimized by shifting the soil weight away from the trench opening. Trench collapses can also be minimised by placing trench sheets on both sides of the trench.

When trenches reach a depth of 5 feet or more, OSHA requires contractors to use a protective system. Protective systems are also required for trenches less than 5 feet deep if the soil might have the propensity to cave in when the trench is dug (such as with sand or mud).

Types of protective systems include sloping, shoring and shielding. OSHA also requires that a safe means of access or egress – such as ladders, steps and ramps – be located within 25 feet of all workers for excavations 4 feet or deeper.

What is the difference between an excavation and a trench? OSHA defines an excavation as any man-made cut, cavity, trench, or depression in the Earth’s surface formed by earth removal. A trench is defined as a narrow excavation (in relation to its length) made below the surface of the ground.

Trench boxes are generally used in open areas, but they also may be used in combination with sloping and benching. The box should extend at least 18 in (0.45 m) above the surrounding area if there is sloping toward excavation.

Line your workers or equipment up with the ditch line, and start to dig. Be careful to observe soil conditions so that the trench embankments do not yield, allowing them to cave in. Dig your first cut to the appropriate depth.

The most expensive trench support methods are shoring methods such as soldier piles, sheet pile, or modular shoring. 3. Soil conditions: Open cut can be made in most soil conditions where ground water can be handled. If obstructions are common the trench production will be slowed for any support system.

Don’t place any excavated soil/material within 2 feet of the trench edge. Don’t stand near any vehicle being loaded or unloaded. Always wear proper safety equipment.

OSHA identifies three basic types of protective systems: shielding (devices designed to protect workers in the event of a collapse, such as trench boxes); shoring (bracing designed to prevent collapse, such as hydraulic shoring or slide-rail systems); and sloping or benching trench walls away from the trench bottom at …

An important step in determining the hazards in a confined space is air testing….Air quality testing

• The oxygen content is within safe limits – not too little and not too much.
• A hazardous atmosphere (toxic gases, flammable atmosphere) is not present.
• Ventilation equipment is operating properly.

In the United States, any pit or trench with a depth equal to or greater than 4 feet is classified as a permit-required confined space. A permit-required confined space has to have one or more specific characteristics, the first being that it contains hazardous gases or has the potential to be a hazardous space.