WASHINGTON (Nov. 2, 2:15 p.m. ET) — In the aftermath of pressure from environmental groups and legislators, the California Environmental Protection Agency has lowered the estimated recycling rate of plastic bags in the 11th-grade teachers’ guide of the state’s K-12 environmental curriculum.

The revised text also deletes a section that had listed several advantages of plastic bags. Among them: that plastic grocery bags require 70 percent less energy to manufacture than paper bags, that they cost less to transport, that they can be reused and that they can be recycled and made into different products. Also deleted was a list of five questions that students could use to determine whether there were advantages to plastic shopping bags.

Instead, the revised guide — issued Oct. 26 — simply says that “plastic bags are durable, lightweight and take up less space than paper bags … and can be recycled.”

With regard to the plastic bag recycling rate, the new text hedges on what that rate may be, saying that “recycling rates specific to plastic shopping bags are not currently calculated by state or federal agencies.”

However, the revised guide does include a reference to a CalRecycle estimate suggesting that recycling rates for plastic bags distributed by stores in California was 3 percent in 2009; and another to an EPA estimate that the nationwide recycling rate for bags, sacks and plastic wrap is 9 percent.

The previous version of the guide, issued in August 2011, had said that 12 percent of Americans recycle plastic bags and film, triggering an outcry from both environmentalists and legislators. That 12 percent figure was taken from federal EPA data submitted to the California EPA by the plastics division of the American Chemistry Council, which has denied trying to influence the curriculum.

“The purpose of our comments was to correct factual inaccuracies, and to present a more complete view of plastic bags’ environmental attributes — including their benefits — which were absent from the draft,” said Steve Russell, vice president of ACC’s plastics department. “Our comments were submitted via email and through an online form on Cal/EPA’s website.

“When Cal/EPA developed its curricula, the agency ... posted an invitation [for public comment] on draft versions of the curricula,” he said. “The American Chemistry Council and dozens of others provided written input, at the request of Cal/EPA. Even some of ACC’s critics agree that we simply did what we and others were asked to do.”

To suggest that the Washington-based ACC tried to unduly influence the process “distorts and misrepresents public process and the role the ACC played in it,” Russell said. “We submitted comments in response to the state’s public solicitation for input.”

An Oct. 29 story from California Watch — an online reporting initiative of the Center for Investigative Reporting — said that Bryan Ehlers, Cal/EPA’s assistant secretary of education and quality programs called the revised curriculum “excellent.”

“This process gave us the opportunity to go through it with a fine-toothed comb,” with the goal of producing a “thoughtful and reasoned discussion about the consequences of consumption,” Ehlers said.

Initially, Cal/EPA had outsourced the development and editing of the curriculum to Gerald Lieberman, director of the State Education and Environment Roundtable, a nonprofit that had been formed by education departments in 16 states to enhance environmental education. In that initial draft, Lieberman had incorporated many of the public comments submitted by ACC and had added the section discussing the advantages of plastic bags.