The stain with the highest resistance to light. It gives the greatest guarantee against yellowing.
It is used in particular on light-colored woods where yellowing stain would result in unpleasant color changes. It gives wood a very natural appearance since it is applied in thin coats without creating a film on the wood.

A silvery-colored metal, soft and very light. It is the third most abundant material found in nature. It can be die-cast or drawn and is then painted or protected with anodic oxidation which makes the surface scratch- and corrosion-resistant. Aluminum not treated in this way oxidizes and thus darkens easily.

Gas that forms during combustion when the carbon in fuel bonds with two oxygen atoms in the air. Carbon dioxide is the prime culprit of the greenhouse effect.

Carbon monoxide is generally the result of incomplete hydrocarbon combustion. This occurs in the home when food is cooked on gas burners. Colorless and odorless, it is a toxic pollutant that bonds with hemoglobin in the blood, preventing it from carrying oxygen through the body. It can cause death by suffocation.

Chlorofluorocarbon, known commercially as Freon, was used widely in the past in the refrigeration industry and as a propellant in spray cans. Widespread use however has led to its accumulation in the stratosphere causing a series of destructive chemical reactions. Since Freon is partly responsible for the hole in the ozone layer, other, more ecological gases are now being used.