Editor’s note: Household paint can be a toxic substance that keeps on giving off VOCs long after it’s dried. This week, Lighter Footstep editor Chris Baskind points us to a healthier, greener alternative to common paints: milk paint. This post was originally published on July 17, 2007.

By now, a lot of people have heard about the hazards of VOCs — Volatile Organic Compounds. In this case, “organic” doesn’t mean they’re good for you.

VOCs are a toxic soup of carbon-based molecules such as ketones, aldehydes, and hydrocarbons. Indoors, they escape from a variety of things you probably take for granted: certain kinds of treated wood, carpeting, plastics, cleaning supplies — even cosmetics. And VOCs vapors tend to hang around.

How big a problem is this? The U.S. Environmental Protection Agency has research showing that indoor air can be 2 to 5 times more polluted than the air you breathe outside. Exposure in effected homes and businesses is chronic, and VOCs are a big contributor to “sick building syndrome.”

A major source of VOCs is household paint. Fortunately, paint manufacturers are getting on the low- or zero-VOC bandwagon, from specialty companies like AFM to old-guard names such as Sherwin Williams.

Concern about VOCs has also led to a revival in milk paint. Milk has been used as a pigment base for thousands of years: it’s cheap, widely available, and imparts a rich glow that was very popular until locally-made paint was displaced by the convenience of non-perishable oils around the middle of the 19th century.

Milk paints hung on as a craft item and for the restoration of historic wall and furniture finishes. But now modern companies are turning out milk paint with the explicit purpose of providing zero-VOC wall coverings for healthy indoor environments.

One such manufacturer is the Old-Fashioned Milk Paint Company. Their one concession to convenience is that they’ve chosen to use dried milk, which allows customers to mix as they go. Otherwise, Old-Fashioned Milk Paint sticks to tradition, choosing clay, ochre, iron oxide, and other natural pigments to arrive at about 20 mixable colors. In theory, you could drink their paint. That’s about as green as it comes.

Got a home project coming up, or are you looking for a way to cover-up a conventional wall finish? Perhaps milk paints are for you. Visit the Old-Fashioned Milk Paint Company website for color ideas, or try one of these other milk paint manufacturers: Real Milk Paint, The Original Milk Paint Company, or Vintage Paint Works.

Feeling a bit do-it-yourself? Check out Pioneer Thinking’s 1870 Milk Paint Formula. Sounds like eco-friendly fun.