Material that can be broken down into simpler substances (elements and compounds) by
bacteria or other decomposers. Paper and most organic wastes such as animal manure are
biodegradable.
Gas or liquid fuel made from plant material (biomass). Includes wood, wood waste, wood
liquors, peat, railroad ties, wood sludge, spent sulfite liquors, agricultural waste,
straw, tires, fish oils, tall oil, sludge waste, waste alcohol, municipal solid waste,
landfill gases, other waste, and ethanol blended into motor gasoline.
A colorless, odorless, non-poisonous gas that is a normal part of the ambient air.
Carbon dioxide is a product of fossil fuel combustion. Carbon dioxide is also exhaled by
animals and used by plants in photosynthesis. Although carbon dioxide does not directly
impair human health, it is a greenhouse gas that traps terrestrial (i.e., infrared)
radiation and contributes to the potential for global warming.
A colorless, toxic gas produced by incomplete burning of carbon-based fuels, including:
gasoline, oil and wood. Carbon monoxide is also produced from incomplete combustion of
many natural and synthetic products. For instance, cigarette smoke contains carbon
monoxide. When carbon monoxide gets into the body, the carbon monoxide combines with
chemicals in the blood and prevents the blood from bringing oxygen to cells, tissues and
organs. The human body needs oxygen for energy, so high-level exposures to carbon monoxide
can cause serious health effects, with death possible from massive exposures. Symptoms of
carbon monoxide exposure include vision problems, reduced alertness, and general reduction
in mental and physical functions. Carbon monoxide exposures are especially harmful to
people with heart, lung and circulatory system diseases.
A motor vehicle pollution control device designed to reduce emissions such as oxides of
nitrogen, hydrocarbons, and carbon monoxide. Catalytic converters have been required
equipment on all new motor motor vehicles sold in California since 1979.
Materials (gases, particles, vapors, chemical compounds, etc.) that come out of
smokestacks, chimneys, and tailpipes. The release of a substance into the atmosphere.
Otherwise known as ethyl alcohol, alcohol, or grain spirit. A clear, colorless,
flammable oxygenated hydrocarbon with a boiling point of 78.5 degrees Celsius in the
anhydrous state. In transportation, ethanol is used as a vehicle fuel by itself (E100),
blended with gasoline (E85), or as a gasoline octane enhancer and oxygenate (10 percent
concentration).
A general term for buried combustible geologic deposits of organic materials, formed
from decayed plants and animals that have been converted to crude oil, coal, natural gas,
or heavy oils by exposure to heat and pressure in the earth's crust over hundreds of
millions of years.
Burning of coal, oil (including gasoline), or natural gas. This burning, usually to
generate energy, releases carbon dioxide, as well as combustion by products that can
include unburned hydrocarbons, methane, and carbon monoxide. Carbon monoxide, methane, and
many of the unburned hydrocarbons slowly oxidize into carbon dioxide in the atmosphere.
Common sources of fossil fuel combustion include cars and electric utilities.
A device (injector) that sprays fuel into air to provide a combustible mixture. Fuel
injection provides better metering of fuel and air than carburetors. This results in more
power, improved fuel economy, and lower emissions. The simplest systems use single or dual
injectors in a central chamber to supply all cylinders. More sophisticated systems use an
injector at each cylinder to precisely meter fuel.
Compounds containing various combinations of hydrogen and carbon atoms. They may be
emitted into the air by natural sources (e.g., trees) and as a result of fossil and
vegetative fuel combustion, fuel volatilization, and solvent use.
An engine in which both the heat energy and the ensuing mechanical energy are produced
inside the engine. Includes gas turbines, spark ignition gas, and compression ignition
diesel engines.
A colorless poisonous liquid with essentially no odor and little taste. It is the
simplest alcohol with a boiling point of 64.7 degrees Celsius. In transportation, methanol
is used as a vehicle fuel by itself (M100), or blended with gasoline (M85).
An ether compound added to gasoline to provide oxygen and enhance complete combustion.
MTBE is a volatile organic compound made as a byproduct of petroleum refinery operations
by combining methanol derived from natural gas and isobutylene.
Gases consisting of one molecule of nitrogen and varying numbers of oxygen molecules.
Nitrogen oxides are produced, for example, by the combustion of fossil fuels in vehicles
and electric power plants. In the atmosphere, nitrogen oxides can contribute to formation
of photochemical ozone (smog), impair visibility, and have health consequences; they are
considered pollutants.
Ozone is created through chemical reactions of "volatile organic compounds"
and oxides of nitrogen (NOx) in the presence of heat and sunlight. NOx emissions are
generally very low in two-stroke engines, however, and cold winter temperatures are not
conducive to ozone formation. So under normal operating conditions snowmobiles do not
cause ozone.
Solid particles or liquid droplets suspended or carried in the air (e.g., soot, dust,
fumes, mist). Any material, except pure water, that exists in the solid or liquid state in
the atmosphere. The size of particulate matter can vary from coarse, wind-blown dust
particles to fine particle combustion products.
A combination of smoke and other particulates, ozone, hydrocarbons, nitrogen oxides,
and other chemically reactive compounds which, under certain conditions of weather and
sunlight, may result in a murky brown haze that causes adverse health effects. Under
normal operating conditions, snowmobiles do not cause smog.
Most modern snowcoaches are vans that have had their wheels removed and replaced with
large rubber treads. They offer a smooth and quiet ride. Snowcoaches are enclosed and
heated vehicles that travel on tank treads over the snow.
A motorized vehicle that runs on tracks or skis or a combination thereof, weighs less
than 2,000 pounds and is designed to be primarily driven on snow, ice or both.
A professional association that among other things establishes industry
"standards" for tools and repairs, including A/C service procedures, recovery,
recycling and leak detection equipment, refrigerant purity, etc.
In contrast to the four-stroke or Otto Cycle engine, which produces a power stroke on
every fourth stroke, the two-stroke, or Clerk Cycle, engine provides a power stroke for
every other stroke. The two-stroke engine, unlike the four-stroke engine, does not need a
camshaft to operate intake and exhaust valves, nor does it require complex, poppet-type
valves themselves. In the two-stroke engine, the piston itself, moving past intake and
exhaust ports in the cylinder wall, acts as a kind of sleeve valve. Lubrication is
provided in vaporized form with the fuel, rather than from an oil reservoir and pump
system.
Carbon-containing compounds that evaporate readily into the atmosphere at normal
temperatures (with a few exceptions). VOCs often have an odor, and some examples include
gasoline, alcohol, and the solvents used in paints. VOCs contribute significantly to
photochemical smog production and certain health problems.
