Local Republicans think they’ve scored a political gotcha on the bag tax.

A letter addressed to D.C. Council Chairman Vincent C. Gray points out that the bag-tax legislation that went into effect earlier this year seems to have made an error in defining what a “reusable” plastic bag is.

The error lies in the difference between a millimeter and a ‘mil’—-an industry-standard unit of thickness equivalent to a thousandth of an inch. A millimeter, one-thousandth of a meter, is much thicker. The typical disposable plastic grocery bag is a mere half-mil thick; dry-cleaning bags get into three-quarter mil territory. A 2.25 mm plastic bag would be equivalent to 88.6 mil.

In several minutes of Googling, LL was not able to find a purveyor for plastic bags anywhere near that thick. Now 2.25 mil, on the other hand, is a little over a half-millimeter thick, and LL found plenty of sources for “eco-friendly” reusable bags of that type.

D.C. GOP interns are distributing the letter around the John A. Wilson Building today, along with sample pieces of 2.25 mm plastic—-which “similar to the thickness of a two CDs laid on top of each other,” according to the letter. (Note the stray “a”—-legislators have no monopoly on typos.)

“It is our hope and the hope of the District’s business community that the DC Council will be more thorough when passing legislation that will dramatically impact the lives and jobs of thousands of District residents,” reads the letter, penned by D.C. GOP chair Robert Kabel.

Charles Allen, chief of staff for Ward 6 councilmember and bag-bill introducer Tommy Wells, says the 2.25 mm spec didn’t originate with the D.C. Council. “We pulled that specific language from other jurisdictions. We didn’t pull that out of the air,” he says, later providing model language from legislation in California, Texas, and Hawaii.

He also points out that the plastics industry, which fought the bill tooth and nail, never mentioned the millimeter/mil issue. “When the American Chemistry Council came and testified, you’d think they would have brought it up if it was a real concern,” he says.

What are the practical impacts of this error? Slight, if any. The legislative definition comes into play in defining what kind of bags are exempt from the five-cent bag fee and what type of bags can be purchased and distributed with the fee’s proceeds. Virtually all of the reusable bags that LL has seen handed out in recent months—-including those distributed by D.C. Republicans—-are made of some sort of cloth, not plastic. And all of the reusable bags distributed by the District government thus far, Allen says, have been made of cloth.

But, hey, a gotcha’s a gotcha!

“As you will discover, this level of thickness almost makes it impossible to produce a reusable bag and comply with District law,” Kabel writes. “We hope that in addition to being more thorough, the Council will not impose fines on the District’s business community due to an error that originated from the Council.”