U.S. EPA yesterday missed its proposed deadline to finalize and release its chemical risk assessment of dioxin, drawing fire from environmentalists and health advocates.

Last August, the agency said it would release its final Integrated Risk Information System (IRIS) assessment of the non-cancer effects of the substance by the end of January. The assessment would likely pave the way to stricter regulations on dioxin.

But yesterday came and went, and EPA released only a statement: "EPA is working to finalize the non-cancer health assessment for dioxin as expeditiously as possible."

Dioxin is a family of chemicals that is both naturally occurring and a byproduct of industrial processes such as waste incineration.

The agency began its review of the substance, a suspected carcinogen and frequent contaminant at Superfund sites, 27 years ago. That review has been repeatedly delayed in the face of significant industry opposition.

Environmentalists and public health advocates lambasted EPA for not releasing the IRIS assessment yesterday.

"Shame on EPA Administrator Lisa Jackson for denying parents the information they need to protect their children from the health impacts of dioxin," said Lois Gibbs, executive director of the Center for Health, Environment and Justice, in a statement. "This is America -- parents have the right to know."

Gibbs has pressed EPA to crack down on dioxin for 30 years. She gained fame in the 1970s for her fight to force EPA to clean up dioxin contamination in her Niagara Falls, N.Y., neighborhood, Love Canal. Her efforts led to the passage of the Comprehensive Environmental Response, Compensation and Liability Act, which established EPA's Superfund cleanup program.

Gibbs, the author of "Dying from Dioxin," said industry was directly responsible for the delay.

"Today the EPA has once again caved into pressure from Dow Chemical and their chemical industry cronies," Gibbs said. "EPA shouldn't cave in to chemical industry dollars and interests over public health."

Various industries have indeed been vocal on calling on EPA to delay or re-evaluate the dioxin assessment. At the end of last year, various food industries wrote the White House urging it to push back the assessment because the proposal set forth a dioxin limit that was three times lower than the World Health Organization's.

Such a limit, according to trade associations such as the American Farm Bureau Association and the International Dairy Foods Association, would unjustifiably alarm consumers (Greenwire, Dec. 21 2011).

The American Chemistry Council (ACC), which previously called for EPA to re-evaluate the dioxin assessment, said scientific problems remain with the assessment.

"ACC supports the strong regulation of dioxin based on sound science and urges the EPA to work with the Administration and other agencies to publish a complete dioxin reassessment that addresses the multiple concerns outlined by the National Academy of Sciences (NAS) and other reputable scientists," ACC said in a statement.

"For years," the group added, "a broad and consistent chorus of scientists, experts, other federal agencies and stakeholders has expressed strong concerns that the draft dioxin reassessment is significantly flawed."

ACC also said EPA has yet to consider the economic impact of the dioxin assessment.

"Since the EPA contends the primary route of human exposure to dioxin is through food, the draft reassessment could not only mislead and frighten consumers about the safety of their diets, but could have significant economic implications on U.S. food producers," ACC said. "Furthermore, this flawed dioxin reassessment could stifle job growth, jeopardize land-based tax revenues, and harm brownfield redevelopment."

EPA scheduled splitting its dioxin assessment into two reports -- cancer and non-cancer assessments -- last August. It said the non-cancer report would be released by the end of January, while the cancer section would be released shortly thereafter.

The World Health Organization and U.S. National Toxicology Program have classified high exposure to dioxin as carcinogenic. Other studies have linked it to neurodevelopment problems in children as well as effects on hormonal and reproductive systems.

In the past few weeks, EPA has received letters from more than 30 groups -- ranging from Rep. Ed Markey (D-Mass.) to the Natural Resources Defense Council (NRDC) to the Teamsters union to the Vietnam Veterans of America -- urging EPA to release the assessment by the end of January.

Jennifer Sass, a senior scientist at NRDC, said that finally finishing the risk assessment is critical.

"We, the people, need the federal government -- our government -- to issue a clear scientific report that dioxin is a highly toxic chemical, so that state and federal regulators can use that to set health-protective limits on dioxin in our food, water and environment," Sass wrote in a blog post this morning.

Gibbs said EPA must finalize the assessment immediately.

"We call on EPA Administrator Lisa Jackson to immediately release this important report," she said. "We can't wait any longer."