WASHINGTON -- Even as top chemical manufacturers are phasing out production of polybrominated diphenyl ether (PBDE) flame retardants, the US EPA has slowed its drive to ban the toxic chemicals in response to intense lobbying from multiple fronts, including the Pentagon.

In 2010, EPA proposed a set of rules that would prevent companies from selling or importing products containing PBDEs. Although some of the bans are voluntary, the three largest manufacturers of PBDEs have consented to go along.

But lobbies for various interest groups representing everything from autos and airplanes to appliances and defense equipment have pushed back, hoping to eliminate or tone down the rules, which demand suppliers to show proof their products are safe prior to being allowed on the market.

Peer-reviewed research indicates the chemicals that make up PBDEs have shown up in staggering amounts in adults and infants in the US.

In a twist, Albemarle, Chemtura and ICL Industrial Products, the three major PBDE makers, are on board with the proposed EPA rules, and are fighting efforts to have them watered down. The companies have invested in alternate flame retardant chemistries and are concerned maintaining the status quo could undermine those efforts.

Complicating matters are recent efforts by the US Defense Department to sway the EPA to leave deca, which is common in printed circuit boards, on the market for another five years.

Certain PBDEs, including deca,  have been banned in the EU, and China's proposed RoHS revisions also curtail their use. In 2009, the US House of Representatives took up a measure called the "Environmental Design of Electrical Equipment Act (EDEE) Act" (H.R. 2420), which proposed to amend the 1976 Toxic Substances Control Act. While IPC in the past fought against the ban, the PCB industry trade group has relented in recent years.

What's interesting about the debate is that the chemistries in question don't even do what they are marketed to do -- that is, retard flame -- as a Chicago Tribune investigation revealed earlier this year.

The EPA is currently reviewing public comments on the matter.