In less than a year, O'Rourke and a team of scientists and engineers working out of an office in downtown San Francisco have analyzed the ingredients in more than 75,000 products. And they have rated them from 0 to 10 – with 10 being the best score – based on their environmental impact, as well as on health and social factors.

It's all in the name of transparency, O'Rourke says. Even the savviest shopper knows little about most ingredients listed on the most common grocery store items. With GoodGuide providing better information, the public "will make better choices about what they buy," says O'Rourke, a professor of environmental and labor policy at the University of California, Berkeley. "Transparency will make the world better."

For instance, who knew that aluminum starch octenylsuccinate, an ingredient often found in men's grooming products, was a neurotoxin – or that an active ingredient in most sunscreens is oxybenzone, which, when exposed to sunlight, is potentially carcinogenic?

"We basically don't know anything about the products we buy. In some ways, we live in the Dark Ages when we go shopping," he says.

For most of his academic career, O'Rourke has analyzed the environmental and social impact of the massive global supply chain by which most goods end up on American shelves. He's worked in Chinese factories and with major American corporations.

But when he began thinking about the products in his own house, he realized he knew very little about what he was actually using.

O'Rourke began by investigating the contents of the sunscreen and shampoo he purchased for his daughter. He was surprised about what he found – skin irritants and carcinogenic properties.

Along with his Berkeley students, he started examining other products. They found that a fruit drink, which advertised itself as healthy, contained more sugar than a soft drink. They found toys covered in toxic lead paint. And they developed a database – which sparked the idea for GoodGuide.com. While they were discovering bad stuff, they also started looking for alternatives. "Almost immediately I moved from the bad news...," O'Rourke says. "I wanted to find the good products."

Items are rated from 0 to 10, but few land at those extremes. A rating between 6 and 8 would be good, while 3 to 5 would be not-so-good. GoodGuide says it uses more than 600 criteria to evaluate products. When considering environmental impact, for instance, it looks at data on the product's entire life cycle – from how it's manufactured to how it decomposes in a landfill. In terms of corporate social values, GoodGuide looks at worker pay, disclosure policies, and charitable contributions.

An item might receive a high health score but an average environmental rating. For instance, Burt's Bees Medicated Lip Balm scored a perfect 10 in health but 7.6 in environmental impact for an overall score of 8.6. Consumers can decide which categories they value most.

GoodGuide has arrived at a time of growing consumer consciousness about the health and environmental effects of consumer goods. It also comes as more and more companies are marketing their products as being "green" – organic, ecofriendly, natural, or nontoxic. Part of the role of GoodGuide is to be a fact checker for consumers and ensure that advertisers and manufacturers aren't "greenwashing" their wares.

"It is currently virtually impossible for an average consumer to access the information they need to evaluate if a product is truly green or healthy," O'Rourke recently told a congressional panel looking into "green" marketing.

Consumer advocates are calling for new federal green-marketing standards – similar to guidelines the United States Department of Agriculture uses for organic certification. While the Federal Trade Commission has gone after companies for falsely marketing products as green and has said it will issue new guidelines for environmental marketing, critics say that the FTC isn't moving fast enough.

Kevin Tuerff, president of the environmental-marketing agency Enviromedia, says the government could offer a "green seal" that would verify a product's environmental claims. "If you can make green purchasing easy, then I think more and more people will do it," he says.

That's where GoodGuide's iPhone app comes in handy, O'Rourke says. He is in talks with several grocery retailers to sync their inventory with his database to allow GoodGuide users to quickly find the products they care about. He envisions GoodGuide users walking into a market and their iPhone's location-tracking software recognizing that they just entered the store. From there, the phone tells them which aisle has highly rated organic pasta or an ecofriendly bottle of shampoo.

"We want to help people find the products that match their values," O'Rourke says.

Companies are beginning to see that a world of "radical transparency" about their products is coming, O'Rourke says.

"Product-ratings tools like the GoodGuide are creating awareness for consumers...," Drummond Lawson, environmental strategist of the San Francisco-based home care and personal products company Method, said in an e-mail response to questions. "In March of 2009, we published the technical names on our website product pages. This was part of a strategy to empower consumers to better validate the health and environmental effects of the products they purchase."

"There's a whole world asking for this information," O'Rourke says, and GoodGuide is trying to keep up with the demand. It will keep reviewing new products, tweaking its website, and improving its iPhone app – all in an effort to help people become smarter shoppers.