How are coating materials getting greener?

We admit this would have to be messier if it were actually a desk at HowStuffWorks, but think about it: Everything in this image (except possibly the jar, plant and coffee in the mug) has been treated with at least one kind of paint, sealant, varnish or other coating. See more green science pictures.

Look up from your computer for a moment: Of all the things in your field of view -- furniture, books, appliances and even the walls and carpet -- how many have some type of coating on them? Are they painted? Do they have glossy or flat finishes? Are they painted or stained? If you think about it, it may be easier to count the uncoated things around you than all those that feature some form of cosmetic or performance coating.

Coatings are everywhere. We paint our walls to change the mood in our rooms. We coat cookware with nonstick substances to keep food from burning. Our clothes have coatings that deflect rain when we're caught out in a shower. And when you consider the number of industrial and medical products that are coated with insulation, sound-deadening material or UV-resistant finishes, you start to realize just how much coatings affect our everyday lives.

These coatings also affect the environment. For example, many coatings that must have some flexibility incorporate petroleum-based polymers like low-density polyethylene (LDPE). And like other oil-based products, these nonbiodegradable substances can fill landfills and sap nonrenewable resources if not properly handled or recycled. Other coatings, such as the anodizing process used to add color and durability to many aluminum products, produce highly toxic chemicals such as sulfuric acid (a contributor to acid rain) and aluminum hydroxide (which can contaminate groundwater if not disposed of properly) [source: Thomas Publishing Company].

But the movement to lessen our collective impact on the planet is affecting coating technology, and the scope of this huge category of materials means that these green changes could significantly reshape humankind's environmental footprint. Some coatings are getting greener than others, and because of the variety of materials that fall into this category, there are a wide range of ways coatings are going green. Read on to learn some of the basics of how coating technology is taking small steps that could have an enormous green impact.