A number of 529 college savings plans are adding more socially responsible investments to their lineups.

At least one—the District of Columbia College Savings Plan—provides enough funds to create a diverse SRI portfolio.

The D.C. plan was designed that way because "we thought it would give D.C. a niche," says Laurent Ross, college savings plan manager for Calvert Investments, which manages the plan. "Almost all of our out-of-state clients use us because of the SRI."

SRI funds typically screen out investments in companies that pollute or are involved in such products as alcohol and tobacco. Demand has grown significantly in recent years, especially for so-called green funds, although some industry experts say demand is still limited among investors in 529 plans.

"I haven't seen a huge groundswell," says Joe Hurley, founder of Savingforcollege.com LLC, a company owned by Bankrate Inc. that provides information about 529 savings plans.

Still, advisers who specialize in SRI say they are finding more families want the option for college savings. "A lot of people don't know that there is a good SRI 529 plan available," says Eric Packer, a senior investment adviser at Progressive Asset Management in Wellesley Hills, Mass. He says his clients prefer using the D.C. college savings plan despite potentially higher fees than, say, a direct-sold plan. Assets in the D.C. plan are still relatively small at more than $131 million, up 43% in 2009.

Jon Ellenbogen, a financial adviser with Wells Fargo in Washington, D.C., recommends that clients begin by looking at the 529 savings plan in their home states because many states offer tax and other benefits in addition to the federal tax benefits. He often uses the District of Columbia plan—especially for in-state clients—but says investors also should weigh performance and fees.