It’s been a few years since Massachusetts voters legalized the use of medical marijuana in the state and, after what translates to a comedy of errors as far as licensing and regulations, the first dispensary is finally slated to open this summer. But there’s still one more hurdle coming out of left field for properly certified Bay State tokers to clear before they can legally light up: heavy metal.

No, not like the Boston hardcore band the Dropkick Murphys, or any other head-banging hessian rock group. It’s actual heavy metals—specifically lead, arsenic, mercury, and cadmium—that are the most recent thorn in the side of the state’s budding cannabis industry.

And now marijuana testing laboratories are crying foul at the abnormally restrictive requirements, which, in the case of lead, is 50 times more stringent than Colorado’s. For mercury, medically safe pot in Massachusetts requires a level half of that normally found in a can of tuna.

It’s so restrictive, in fact, that no sample can pass muster.

“To date, every sample of cannabis that we have tested for heavy metals, particularly lead, would fail the existing regulations,” said Chris Hudalla, chief scientific officer of one of the state’s two marijuana testing facilities, told local NPR affiliate WBUR.

The state’s threshold is based, he adds, on an estimated ingestion of 10 ounces of marijuana per patient every 60 days, which is itself a wild figure. If one were to make the conservative estimate of 50 joints per ounce—most dispensaries roll half-gram marijuana cigarettes—that’s 500 total, or a little over eight per day.

That’s an amount that puts you firmly in Snoop Dogg vs. Cheech and Chong territory.

While failing the metal test prohibits sale of weed for smoking or otherwise ingesting, the cannabinoids can still be extracted for use in tinctures, pills, oils, and edibles—which can then be sold. Conversely, Hudalla also pointed out that potatoes or celery purchased in your local produce section may have similar levels of heavy metals present.

Yes, you heard that right: It’s OK for your veggies, which you feed to your kids, to contain a higher level of certain toxins than it is for anyone’s pot. Who knows how these measure up against whatever poisons are in cigarettes?

To the credit of Massachusetts lawmakers, this isn’t the first time that potential contaminants in cannabis have raised a red fag. An article in Smithsonian this year noted that, while careful cultivation has as much as tripled THC levels in marijuana in the past couple decades, there was also a high level of fungi and bacteria.

“It’s pretty startling just how dirty a lot of this stuff is,” Andy Lafrate, of Colorado lab Charas Scientific, said in the piece. He does note, however, that concentrates of THC—like the aforementioned edibles, oils, or pills—will show increased levels of whatever contaminate, including heavy metals, in the original material.

In other words: Just because you’re not smoking your stash to get high doesn’t mean you’re not going be at risk when you eat weed laced with lead or arsenic.

The issue in Massachusetts, of course, is that no plants can pass muster under its draconian regulations. This strict limit on metals is a little surprising, considering the seemingly lax approach to other potential poisons, like pesticides.

All marijuana grown for sale in Mass dispensaries must be submitted to an accredited lab, where they are tested for various compounds, including heavy metals and cannabinoids, the active ingredients in the plant. Those labs then send results to the dispensaries, which report them to the state.

But as far as pesticides go, there is only a list of what cannot be used. This has some officials worried that certain harmful pesticides that (for whatever reason) are not on the official banned list may go unnoticed—and that dispensaries will keep findings to themselves, so as not to hurt profits.

This should be of much greater public safety concern than the state’s seemingly insurmountable metals limits, because, as Hudalla pointed out, “Lead is a naturally occurring element, and there’s a significant difference between lead in the environment and contamination levels of lead.”