Companies should look for potential conflicts of interest between the certifier and business or product and evaluate the professional stature of the certifying staff, she said. There should also be a level of transparency that allows anyone to look at the standards required for a certification.

Even self-verification programs, which have less oversight, can still have value, said Ceil Scandone, regional program coordinator of the Bay Area Green Business Program, which is independently verified by a utility or county agency. "If you have integrity and resources, even the self-verifications have a use as an educational tool," she said.

Hinton applauds any company that tries to improve its environmental practices. Often, companies must often go through a self-verification process because it a new area in terms of environmental compliance.

"Having said that, once that company tries to market its certification, then I think it's imperative for the company to have a seal of approval from a credible nonprofit certification program," Hinton said. "It will give the company greater credibility in the marketplace."

Yet certifications can go in the opposite direction. Some standards can be too stringent to attract participation, said Stephan Sylvan of the U.S. Environmental Protection Agency. Trying to reduce near term environmental impacts won't happen if only a small part of the market participates.

"The monitoring and verification work is critically important to maintain credibility of the initiative and confidence of the buyers. That's really key," said Sylvan, who coordinates the EPA's dozens of voluntary programs, such as Energy Star And WasteWise. "It is possible in some cases for people to go too far and chill the market. Some level is important but striking that balance is key."

Tilde Herrera is associate editor at GreenBiz.com.