OSHA Tower Terms – Flashcards

An electrical circuit that switches polarity regularly, based on a number of cycles per second.

An effect of chemical exposure that happens suddenly, typically from a single exposure.

A suspension scaffold equipped with a hoist that can be operated by an employee on the scaffold

The unit by which the flow of current through a conductor is measured

American National Standards Institute

Sanctioned, endorsed, accredited, certified or accepted as satisfactory by a duly constituted and nationally recognized authority or agency

A discharge of electricity through a gas, such as air

A secure point of attachment for lifelines, lanyards or deceleration devices

A person approved or assigned by the employer to perform a specific type of duty or duties or to be at a specific location or locations at the jobsite

A strap with means both for securing it about the waist and for attaching it to a lanyard, lifeline or deceleration device. Body belts are not acceptable as part of a personal fall arrest system

Straps that may be secured about the employee in a manner that will distribute the fall arrest forces over at least the thighs, pelvis, waist, chest and shoulders, with means for attaching it to other components of a personal fall arrest system

A rigid connection that holds one scaffold member in a fixed position with respect to another member, or to a building or structure

Equipment is "certified" if it (a) has been tested and found by a nationally recognized testing laboratory to meet nationally recognized standards or to be safe for use in a specified manner, or (b) is of a kind whose production is periodically inspected by a nationally recognized testing laboratory, and (c) it bears a label, tag or other record of certification

A plan that provides a written program that sets forth procedures, equipment and work practices that protect employees from the health hazards found in laboratories.

A wedge, block or large stone placed against the tires of a vehicle to prevent it from moving, especially on an incline

An adverse health effect resulting from long-term exposure to a substance. The effects could be a skin rash, bronchitis, cancer or any other medical condition

The path along which electric current flows from start to finish. The circuit includes the generator or battery that starts the current, the wires, and any electrical device that the current operates. If any part of the circuit is removed, the current cannot flow. The circuit is then broken or open. Because electric current seeks to complete its circuit, it will travel along any path that is presented (path of least resistance), which is why humans are at risk of electrocution when they handle damaged tools or cords, or contact un-insulated wires. In effect, they become part of the circuit.

A protective device that automatically opens, or trips, a circuit, without damage to itself, when the current exceeds a predetermined level

A structural block used at the end of a platform to prevent the platform from slipping off its supports. Cleats are also used to provide footing on sloped surfaces such as crawling boards.

One who is capable of identifying existing and predictable hazards in the surroundings, or working conditions that are unsanitary, hazardous or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate the hazards

A substance or body that allows a current of electricity to pass continuously along it. Metals, such as copper or aluminum, are good conductors. In a circuit, current-carrying wires are termed "conductors," as in a flexible cord

A device that is used to couple (connect) parts of the personal fall arrest system and positioning device systems together. It may be an independent component of the system, such as a carabiner, or it may be an integral component of part of the system, such as a buckle or D-ring sewn into a body belt or body harness, or a snaphook spliced or sewn to a lanyard or self-retracting lanyard

Work for construction, alteration and/or repair, including painting and decorating

Two braces that cross each other in the form of an X

The flow of electrons through a conductor, measured in amperes (amps). If the current flows back and forth through a conductor, it is called alternating current (AC). If the current flows in one direction only, as in a car battery, it is called direct current (DC). AC is most widely used because it is possible to increase ("step up") or decrease ("step down") the current through a transformer. For example, when current from an overhead power line is run through a pole-mounted transformer, it can be stepped down to normal household current. Also, alternating current can travel enormous distances with little loss of voltage, or power.

When alternating current flows back and forth through a conductor, it is said to cycle. In each cycle, the electrons flow first in one direction, then in the other. In the United States, the normal rate for power transmission is 60 cycles per second, or 60 Hertz (Hz)

Constant current in single direction. Direct current is produced by batteries, fuel cells, rectifiers and certain generators

An electrical switch requiring consistent pressure to hold the trigger in the "on" position

Any mechanism, such as a rope grab, rip-stitch lanyard, specially- woven lanyard, tearing or deforming lanyard, automatic self-retracting lifeline/lanyard, etc., that serves to dissipate a substantial amount of energy during a fall arrest, or otherwise limit the energy imposed on an employee during fall arrest

The additional vertical distance a falling employee travels, excluding lifeline elongation and free fall distance, before stopping, from the point at which the deceleration device begins to operate. It is measured as the distance between the location of an employee's body belt or body harness attachment point at the moment of activation (at the onset of fall arrest forces) of the deceleration device during a fall, and the location of that attachment point after the employee comes to a full stop.

To free from any electric connection and/or electric charge

Any characteristic or condition that tends to weaken or reduce the strength of the tool, object or structure of which it is a part

The flow of an atom's electrons through a conductor

A conductor used to establish electrical contact with a nonmetallic part of a circuit

To direct electric current through a conductor. Power lines and wires can be intentionally energized (or de-energized) to carry current to an electrical device. But conductive surfaces that are unintentionally energized, like the metal case of a tool, the metal housing of a circuit box, or a metal object such as an aluminum ladder, present a danger of electrocution

Alternative designs, materials or methods to protect against a hazard that the employer can demonstrate to provide an equal or greater degree of safety for employees than the designs, materials or methods specified in the standard

A scaffold consisting of platforms supported on fabricated end frames with integral posts, horizontal bearers and intermediate members

Load refusal, breakage or separation of component parts. Load refusal is the point where the ultimate strength is exceeded

The breakage, displacement or permanent deformation of a structural member or connection so as to reduce its structural integrity and its supportive capabilities

An insulation failure that exposes electrified conductors, causing current to leak and possibly resulting in electric shock

The total system of support for freshly placed or partially cured concrete, including the mold or sheeting (form) that is in contact with the concrete as well as all supporting members including shores, reshores, hardware, braces and related hardware

The act of falling before a personal fall arrest system begins to apply force to arrest the fall

The vertical displacement between onset of the fall and just before the fall arrest system begins to apply force to arrest the fall. This distance excludes deceleration distance, and lifeline/lanyard elongation, but includes any deceleration device slide distance or self-retracting lifeline/lanyard extension before they operate and fall arrest forces occur

A protective device that allows a piece of metal to become part of a circuit. The metal melts under heat created by excessive current, thereby interrupting the circuit and preventing the flow of electricity from exceeding the circuit's current-carrying capacity

A device that detects an insulation failure by comparing the amount of current flowing to electrical equipment with the amount of current returning from the equipment. Whenever the difference is greater than 5 milliamps, the GFCI trips and thereby interrupts the flow of electricity

A conducting connection, intentional or unintentional, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth

A fault, or insulation failure, in the wire used to create a path to ground

To prevent the buildup of hazardous voltages in a circuit by creating a low- resistance path to earth or some other ground plane

Placement of live parts of electrical equipment where they cannot accidentally be contacted, such as in a vault, behind a shield, or on a raised platform, to which only qualified persons have access

A barrier erected to prevent employees from falling to lower levels. A standard guardrail is approximately 42" high and includes a mid-rail that is approximately 21"

An atmosphere that by reason of being explosive, flammable, poisonous, corrosive, oxidizing, irritating, oxygen deficient, toxic or otherwise harmful, may cause death, illness or injury

A substance that, by reason of being explosive, flammable, poisonous, corrosive, oxidizing, irritating or otherwise harmful, is likely to cause death or injury

A chemical is said to present a health hazard if there is statistically significant evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees

A manual or power-operated mechanical device to raise or lower a suspended scaffold

A gap or void 2 inches (5.1 cm) or more in its least dimension, in a floor, roof or other walking/working surface.

Impossible to perform the construction work using a conventional fall protection system (i.e., guardrail system, safety net system or personal fall arrest system) or technologically impossible to use any one of these systems to provide fall protection

To swallow or take in for digestion

The act or an instance of drawing in a breath

An act or instance of injecting, such as a needlestick

Non-conductive materials used to cover or surround a conductor, permitting it to be handled without danger of electric shock

Any material, such as glass or rubber, that prevents the flow of electric current

A method commonly used to assess what specific types of hazards are involved with individual jobs. The findings from the JHA can then help the employer determine what types of controls can be put into place to minimize the likelihood of an injury or illness. Also referred to as a Job-Safety Analysis (JSA)

1000 watts

A mobile, fixed-size, self-supporting ladder consisting of a wide flat tread ladder in the form of stairs

A platform at the end of a flight of stairs

A flexible line of rope, wire rope or strap that generally has a connector at each end for connecting the body belt or body harness to a deceleration device, lifeline or anchorage

The edge of a floor, roof or formwork for a floor or other walking/working surface (such as the deck) that changes location as additional floor, roof, decking or formwork sections are placed, formed or constructed. A leading edge is considered to be an "unprotected side and edge" during periods when it is not actively and continuously under construction

A component consisting of a flexible line connected vertically to an anchorage at one end (vertical lifeline), or connected horizontally to anchorages at both ends (horizontal lifeline), that serves as a means for connecting other components of a personal fall arrest system to the anchorage

The placement of a lockout device on an energy isolating device, in accordance with an established procedure, ensuring that the energy isolating device and the equipment being controlled cannot be operated until the lockout device is removed

A roof having a slope less than or equal to 4 to 12 (vertical to horizontal)

Those areas or surfaces to which an employee can fall. Such areas or surfaces include, but are not limited to, ground levels, floors, platforms, ramps, runways, excavations, pits, tanks, material, water, equipment, structures or portions thereof

Material Safety Data Sheets are prepared by manufacturers and are required to be prepared and delivered in many circumstances in the United States. They are to be made available upon inquiry to a manufacturer by workers, consumers and users of any kind. Also called Safety Data Sheet (SDS)

The total load of all persons, equipment, tools, materials, transmitted loads and other loads reasonably anticipated to be applied to a scaffold or scaffold component at any one time

A unit of measurement equaling one thousandth (1/1000) of an ampere

An abnormal condition or disorder, other than one resulting from an occupational injury, caused by exposure to environmental factors associated with employment. It includes acute and chronic illnesses or diseases that may be caused by inhalation, absorption, ingestion or direct contact

An injury such as a cut, fracture, sprain, amputation, etc., that results from a work accident or from a single instantaneous exposure in the work environment

The unit by which resistance to electrical current is measured. From Ohm's Law (Current=Voltage/Resistance, or in other words, Current=Voltage/Ohms), a mathematical expression of the relationship between these three elements

A gap or void 30 inches (76 cm) or higher and 18 inches (48 cm) or wider, in a wall or partition, through which employees can fall to a lower level

Any current in excess of the rated capacity of equipment or of a conductor

A system used to stop an employee in a fall from a working level. It consists of an anchorage, connectors and a body harness, and may include a lanyard, deceleration device, lifeline or suitable combinations of these. As of January 1, 1998, using a body belt for fall arrest is prohibited

In AC power systems, load current is drawn from a voltage source that typically takes the form of a sine wave. Ideally, the current drawn by the loads in the system is also a sine wave. With a simple, resistive load such as a light bulb, the current sine wave is always aligned with the voltage sine wave. This is called single-phase. A single-phase power system normally uses three wires, called hot, neutral and ground, and the voltage is typically 120/240. Most home and office outlets operate in this manner. With some loads, such as motors, and in high voltage systems, the current sine wave is purposely delayed and lags behind the voltage sine wave. The amount of this lag is expressed in degrees and is called a phase difference. A common example is three-phase power, where the system has three "hot" wires, each 120 degrees out of phase with each other

A work surface elevated above lower levels. Platforms can be constructed using individual wood planks, fabricated planks, fabricated decks and fabricated platforms

A device to which the conductors of a cord are attached, which is used to connect the permanently attached conductors to a receptacle

The relationship between poles of positive and negative charge, particularly with regard to wiring of conductors where the ungrounded (hot) conductor and grounded (neutral) conductor form a circuit

A body belt or body harness system rigged to allow an employee to be supported on an elevated vertical surface, such as a wall, and work with both hands free while leaning

One who, by possession of a recognized degree, certificate or professional standing, or who by extensive knowledge, training and experience, has successfully demonstrated his or her ability to resolve problems relating to the subject matter, the work or the project.

A channel designed expressly for holding wires, cables or busbars, including conduit, tubing, wireways, busways, gutters or moldings

The manufacturer's specified maximum load to be lifted by a hoist or to be applied to a scaffold or scaffold component

The stated operating limit of a piece of equipment, expressed in a unit of measure such as volts or watts

A device, such as a jack or an outlet, to which conductors are attached, and where a plug makes contact with a source of electric current

A person who is registered as a professional engineer in the state where the work is to be performed. However, a professional engineer registered in any state is deemed to be a "registered professional engineer" within the meaning of this standard when approving designs for "manufactured protective systems" or "tabulated data" to be used in interstate commerce

Anything that impedes the flow of electricity, particularly in direct current (DC). Resistance is measured in ohms

Vehicle structures such as roll-bars, frames, roll- protective cabs, etc., designed to prevent the vehicle operator from being crushed as a result of a rollover

A deceleration device that travels on a lifeline and automatically, by friction, engages the lifeline and locks so as to arrest the fall of an employee. A rope grab usually employs the principle of inertial locking, cam/level locking, or both

The hoisting, storage, application and removal of roofing materials and equipment, including related insulation, sheet metal and vapor barrier work, but not including the construction of the roof deck

Formerly called Material Safety Data Sheets, Safety Data Sheets are prepared by manufacturers and are required to be prepared and delivered in many circumstances in the United States. They are to be made available upon inquiry to a manufacturer by workers, consumers and users of any kind

The ratio of the ultimate breaking strength of a member or piece of material or equipment to the actual working stress or safe load when in use

A safety system in which a competent person is responsible for recognizing and warning employees of fall hazards

Any temporary elevated platform (supported or suspended) and its supporting structure (including points of anchorage), used for supporting employees or materials or both

A device, usually worn around the waist, consisting of a strap or straps anchored to a vehicle so as to hold a person in his or her seat

A deceleration device containing a drum-wound line that can be slowly extracted from, or retracted onto, the drum under slight tension during normal employee movement, and which, after onset of a fall, automatically locks the drum and arrests the fall

A term that implies that a particular action is mandatory. The employer shall be responsible for the inspection, maintenance and testing of all portable fire extinguishers in the workplace. 29 CFR 1910.157 (e)(1)

A term that implies that a particular action is recommended. Rungs should be kept free of grease and oil. 29 CFR 1910.25 (d)(1)(xi)

A connector composed of a hook-shaped member with a normally closed keeper, or similar arrangement, which may be opened to permit the hook to receive an object and, when released, automatically closes to retain the object. Non-locking snaphooks cannot be used as part of personal fall arrest systems or positioning device systems

A roof having a slope greater than 4 to 12 (vertical to horizontal)

A ramp built of steel or wood, usually used for vehicle access. Ramps made of soil or rock are not considered structural ramps

That which fits, and has the qualities or qualifications to meet, a given purpose, occasion, condition, function or circumstance

Tagout: The placement of a tagout device on an energy isolating device, in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed

A low protective barrier that will prevent the fall of materials and equipment to lower levels and provide protection from falls for personnel

A narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench (measured at the bottom) is not greater than 15 feet (4.6 m)

Any side or edge (except at entrances to points of access) of a walking/working surface, e.g., floor, roof, ramp or runway, where there is no wall or guardrail system at least 39 inches (1.0 m) high

Items whose strength, configuration or lack of stability may allow them to become dislocated and shift and therefore may not properly support the loads imposed on them. Unstable objects do not constitute a safe base support for scaffolds, platforms or employees. Examples include, but are not limited to, barrels, boxes, loose bricks and concrete blocks

The unit by which electrical force or pressure is measured

The fundamental force or pressure that causes electricity to flow through a conductor. Measured in volts

A portion of a scaffold platform used only for access and not as a work level

Any surface, whether horizontal or vertical, on which an employee walks or works, including, but not limited to, floors, roofs, ramps, bridges, runways, formwork and concrete reinforcing steel, but not including ladders, vehicles or trailers on which employees must be located in order to perform their job duties

A barrier erected on a roof to warn employees that they are approaching an unprotected roof side or edge, and that designates an area in which roofing work may take place without the use of guardrail, body belt or safety net systems to protect employees in the area

The unit by which electric energy, or the ability of electricity to do work, is measured. One thousand watts, or one kilowatt, equals 1.34 horsepower