WASHINGTON — It’s certainly well-known in Washington that when it comes to the making of the sausage, lobbyists frequently have their thumbs in the pork. But usually, they don’t actually leave their electronic signatures on bills.

The elaborately titled Frank Lautenberg Chemical Safety for the 21st Century Act makes its debut at a Senate Environment and Public Works Committee hearing Wednesday. It’s a high-stakes bill: If it becomes law, it would be the first update in 39 years of federal regulation of toxic substances like asbestos, formaldehyde and hundreds of other chemicals.

In recent days, a draft of the bill — considered the product of more than two years of negotiation and collaboration between Sen. David Vitter, R-La., Sen. Tom Udall, D-N.M., and both chemical industry and environmental groups — was circulated by Udall’s office ahead of the hearing. The draft bill, obtained by Hearst Newspapers, is in the form of a Microsoft Word document. Rudimentary digital forensics — going to “advanced properties” in Word — shows the “company” of origin to be the American Chemistry Council.

The ACC, as the council is known, is the leading trade organization and lobbyist for the chemical industry. And opponents of the Vitter-Udall bill have pounced on the document’s digital fingerprints to make the point that they believe the bill favors industry far too much.

“We’re apparently at the point in the minds of some people in the Congress that laws intended to regulate polluters are now written by the polluters themselves,” said Ken Cook, president of the Environmental Working Group, who will testify against the bill at Wednesday’s hearing.

“Call me old-fashioned, but a bill to protect the public from harmful chemicals should not be written by chemical industry lobbyists. The voices of our families must not be drowned out by the very industry whose documented harmful impacts must be addressed, or the whole exercise is a sham,” Sen. Barbara Boxer, D-Calif., said Monday.

Boxer, who chaired the committee when the Democrats held the majority, and Sen. Edward Markey, D-Mass., have introduced an alternative version of the bill with much more stringent regulatory provisions.

Udall’s office was a little indignant and somewhat embarrassed Monday. “That document originated in our office,” said Udall’s communications director, Jennifer Talhelm. “It was shared with a number of stakeholders including at least one other senator’s office. One of those stakeholders was the ACC.

“We believe that somebody at the ACC saved the document, and sent it back to us,” Talhelm said, accounting for the digital trail. “Sen. Udall’s office has been very, very engaged with bringing various stakeholders to the table as part of the process of writing the best possible bill,” Talhelm added. “This is just one example.”

Earlier this month, a New York Times story detailed Udall’s alliance with the chemical industry on the bill. In that story, ACC President Cal Dooley, a former California Democratic congressman, said “the leadership (Udall) is providing is absolutely critical” to the industry.

On Monday, ACC spokeswoman and vice president Anne Kolter said, “It doesn’t mean the original document was generated here. Anyone could have put that (digital signature) in there. You could change it.”

Asked if that meant she was denying ACC wrote the document, she said, “I have no idea. ... There’s no way for anyone to tell.”

“You’re not the first reporter to ask about this,” she said. “We’ve been able to raise enough questions” that nobody else has written about it, she added.

Cook of the Environmental Working Group said the copy of the draft he received bore the same electronic signature, and a Boxer staffer on the committee confirmed that their copy did as well. A Senate IT staffer told Boxer’s office, “We can confidently say that the document was created by a user with American Chemistry Council. Their name is specified as Author and their Organization is specified as American Chemistry Council.”

The Vitter-Udall version of the bill is expected to gain enough bipartisan support to pass out of committee to the Senate floor.

The bill’s fate from there is uncertain, and some of the Boxer-Markey provisions could possibly be included in the final bill.

In its current form, the bill is opposed by many environmental, health and labor organizations and several states, because it would gut state chemical regulations.

David McCumber is the Washington bureau chief for Hearst Newspapers. E-mail: david.mccumber@hearstdc.com