Aspect of scientific interest with measurable quantities

Associated with electricity or with electrical force, power, or energy

Alternating current electricity

Direct current electricity

Electromagnetic radiation in the visible spectrum

Relating to energy from the sun

Matter in one the three states solid, liquid, or gas

Plant or animal material used as fuel to produce electricity or heat

Liquid or gas

Substance with neither definite volume nor shape

The mixture of gases which surrounds the earth

Formaldehyde (CH₂O)

Methane (CH₄)

Carbon monoxide (CO)

Carbon dioxide (CO₂)

Hydrofluorocarbons

Nitrous oxide (N₂O)

Fossil fuel energy source consisting largely of methane and other hydrocarbons

Nitrogen trifluoride (NF₃)

Ammonia (NH₃)

Nitrogen dioxide (NO₂)

Oxygen (O₂) - the common dioxygen allotrope in the air

Ozone (O₃)

Perfluorocarbons

By-product of natural gas processing and petroleum refining (C₃H₈)

Sulphur hexafluoride (SF₆)

Water in its gas form

Total volatile organic compound (TVOC)

Substance with definite volume but takes the shape of its container

Liquid phase produced by the condensation of steam or other gas

Liquid fuel specifically designed for use in diesel engines

Petroleum based oil burned for energy

Petroleum derived liquid used as a fuel source

Water in its liquid form

Water expelled from a system to remove mineral build up

Water cooled for use in HVAC and industrial processes

Water supplied to cold taps

Water used used to remove heat through condensation

Relatively cool water without active chilling

Tap water for drinking, washing, cooking, and flushing of toilets

Water present under the ground or from a well

Hot water used for HVAC heating or supplied to hot taps

Water used used to makeup water loss through leaks, evaporation, or blowdown

Water expelled from a system to remove contaminants

Relatively warm water without active heating

Fluid used in refrigeration and heat exchange

Substance with definite shape and volume

Combustible sedimentary rock

Water in its solid form

Particulate matter 0.1

Particulate matter 10

Particulate matter 2.5

Associated with atmospheric air or phenomenon

Flow of air on surface of the Earth