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Lighting: Definitions

 This section contains a glossary of key terms used throughout the Guide.


 Automatic dosing 

techniques in which precise amounts of mercury are inserted into fluorescent and high-intensity discharge (HID) lamps using capsules, alloy strips, metered sprays and other methods that protect workers from hazardous exposure


device used with an electric discharge lamp to obtain necessary circuit conditions to start and operate it


basic information gathered before a program begins that is used later to provide a comparison for assessing program impact


process whereby harmful substances concentrate or magnify as they move up the food chain.


see "compact fluorescent lamp"

Cold cathode fluorescent lamp (CCFL)

a cathode lamp that operates at ambient temperature, resulting in longer lamp life and greater optimal temperature range

Color rendering index (CRI)

measurement of a lamp’s ability to emit light that is a true color, i.e. without yellowing or other color shifting

Compact fluorescent lamp (CFL)

fluorescent light bulb designed to replace incandescent light bulbs, see also "incandescent" and "fluorescent lighting"


using sunlight to illuminate indoor spaces


light output of a lamp divided by its wattage, expressed in lumens per watt


energy efficiency standard managed jointly by the U.S. Environmental Protection Agency and Department of Energy

Environmentally preferable

products and services that have a lesser or reduced effect on human health and the environment when compared to other products and services that serve the same purpose

Fluorescent lighting

gas-discharge lamps that require ballasts and use electricity to excite mercury vapor in argon or neon gas, producing ultraviolet light that causes a phosphor to fluoresce, producing visible light

Hazardous substance

1. material posing a threat to human health and/or the environment, that can be toxic, corrosive, ignitable, explosive, or chemically reactive, 2. substance that must be reported to the EPA if released into the environment.


inefficient technology that produces light by passing an electrical current through a thin filament


light-emitting diode; high efficiency lighting that uses semiconductor technology; aka solid state lighting

Lifecycle cost

adjusted annual cost of a product that accounts for capital, installation, operating, maintenance and disposal costs

Mean lumen output

amount of light that is emitted when a lamp reaches 40% of its rated life


a heavy metal used in fluorescent, HID and neon lamps that can cause short-term and chronic nervous system impairment, cancer, heart disease and other serious health damage to exposed individuals

Mercury vapor lamp

a high intensity discharge (HID) lamp typically used for street lighting and high-bay applications. They are relatively inefficient, tend to depreciate quickly, and often have a low CRI

Persistent, bioaccumulative, toxins (PBTs)

toxic chemicals that persist in the environment and increase in concentration through the food chain; transferred easily through air, water and land ; EPA list includes 4 chemical groups and 16 chemicals.

Polychlorinated biphenyls (PCBs)

mixtures of up to 209 individual chlorinated compounds (known as congeners)

Scotopically enhanced

describes fluorescent lamps with a 5000K temperature or higher


a type of fluorescent lamp with a 5/8” diameter tube; when paired with an electronic programmed start ballast, it is a highly efficient, modern lighting technology


a type of fluorescent lamp with an 8/8” (or 1”) diameter tube; when paired with an electronic ballast, it is a relatively efficient, modern lighting technology


a type of fluorescent lamp with a 12/8” (or 1.5”) diameter tube; it is a relatively old and inefficient technology that runs on a magnetic ballast

Toxic substance

a chemical or mixture that may present an unreasonable risk of injury to health or the environment

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