Earlier this week, Vermont released a draft of the regulations it proposes to adopt in order to enforce the state's mandatory GMO-labeling law.

"The nine pages of rules released Wednesday lay out everything from definitions of 'food' and 'genetic engineering' to the required disclosures on packaging that will read 'Produced with Genetic Engineering,'" notes an Associated Press piece on the proposed regulations.

The proposed rules themselves are interesting enough—but then so are the numerous exceptions built into them.

Unsurprisingly, many of them appear to have Vermont farmers and dairy interests in mind.

Take the exception for foods that contain genetically modified "processing aids or enzymes." While it's not stated explicitly what these aids and enzymes are, it doesn't take much to figure out why the state has proposed this exception to the law.

"Beer, wine and cheese will also need special consideration, since the use of genetically modified enzymes is fairly common when making these products," noted a Whole Foods blog post last year.

How's that? In the case of cheese, it comes down to a genetically modified enzyme, FPC, that's used to make ninety percent of cheeses. It's expensive to make cheese without FPC.

Vermont, of course, is known for its cheese. And beer. Not surprisingly, the regulations also exempt alcohol beverages.

Cherry-picked exceptions like these—which often appear to favor or protect local interests—are common.

"Manufacturers would have to label GMO bread, but not GMO cheese," reads a recent report on Colorado's proposed GMO-labeling law. "Soda, but not beer. Candy, but not gum."

And, as I noted earlier this year, a Hawaii county GMO ban exempts GMO papayas, which (coincidentally!) are grown in the county.

Four national associations, headed by the Grocery Manufacturers of America, sued earlier this year to prevent the Vermont law from taking effect.

They argue, among other things, that the state's GMO-labeling law is unconstitutional. They're right. That's true of every state GMO-labeling law I've seen. And Vermont's is no exception.

Like the California egg law I wrote about last week, GMO-labeling laws restrict interstate commerce. That's the primary reason why I opposed proposed laws in Washington state and California, both of which were rejected by voters.

Defending an unconstitutional law may prove as costly as it is foolhardy.

Reports indicate the state may have to revert to bake sales to fund its defense of its labeling law, which is expected to cost upwards of $8 million. In August, the state announced it had raised just over two percent of the money it expects to need to defend the law in court. Since that time, reports indicate that donations had swollen to less than four percent.

But the real costs might be borne by Vermont's farmers. The requirements in the proposed rules that sellers affirm that any products sold without a GMO label are free from GMOs via a sworn statement may prove daunting.

"I don't want to say our cheese is non-GMO if I can't prove it," said Angela Miller of Vermont's Consider Bardwell Farm, a small, sustainable producer, in comments to the Guardian earlier this year.

With a $1,000 fine proposed for each violation, who could blame her?

Earlier this year, someone asked Vermont Gov. Peter Shumlin what he thought of the state's GMO labeling law.

"I'm not going to think too much about that," said Shumlin. "I usually don't have time to read what I'm eating."

If it hadn't happened already, I'd predict that sort of carelessness was enough to get his state sued.