Hotel housekeeper Damarys Beltran nodded an emphatic "yes" when asked if she notices a difference between the green cleaning products she's using now and the ones she used in her former job.

She can scrub a shower or spray a room without her throat tightening and choking, Beltran said. The sensation was so intense at her former job that she and co-workers would dilute the room spray so they could work comfortably.

That's not necessary at her new job. The Courtyard by Marriott Burlington Harbor in Vermont, which opened last month, is using environmentally friendly cleaning products thanks to a deal with Seventh Generation, a maker of household cleaning products whose headquarters is nearby.

For Seventh Generation, the experiment is a way to dip its toe into the $140 billion industrial cleaning industry. The green side of the market is growing rapidly, while the conventional cleaning side stays flat, green cleaning expert and advocate Stephen Ashkin says.

However, green cleaning is still only a sliver of the market, amounting to less than 10 percent, Ashkin estimates. He served as director of product development at Seventh Generation from 1999 to 2001 and is co-author of the recently released book "Green Cleaning for Dummies."

Green cleaning has garnered a lot of attention on the residential side, with celebrities such as Deirdre Imus, wife of former talk radio host Don Imus, touting a line of green products.

But commercial cleaning products have not been available at competitive prices, Ashkin said.

That started to change in 2002, when Massachusetts approved green products in its guidelines to state agencies for buying cleaning products, Ashkin said. Other states followed Massachusetts' lead and the green commercial industry blossomed.

The hospitality industry has been among the slowest in adopting green cleaning, Ashkin said. Ecolab, based in St. Paul, Minn, has served much of the hotel cleaning industry.

To use Seventh Generation products, the Courtyard by Marriott Burlington Harbor had to bypass Ecolab, which is used throughout the Marriott chain, said Joe Carton, the hotel's general manager.

In addition to making life more pleasant for room attendants, Carton views the green move as smart marketing.

Soon, the 127-room hotel on the Lake Champlain waterfront will advertise its green cleaning in guest rooms.

Seventh Generation, which makes cleaning products for the residential market, reformulated several of its products for the hotel. That meant increasing concentration and adding color to the fluids, which are typically clear. Seventh Generation has not set a timeline for moving into the commercial marketplace on a larger scale.