This is a story about vegan lettuce.

But, wait. Isn’t lettuce…vegan by nature?

Read on. Things are about to get tricky.

In a nondescript warehouse around the corner from Philadelphia’s Italian Market—the one Rocky Balboa famously passed on his jog to glory—Metropolis Farms is working to set itself apart as a leader in a new era of vertical farming. It claims to offer anybody with access to unused industrial, commercial, and residential space a means to establish a productive, lean hydroponic farm just like the one where Metropolis produces lettuce, herbs, and strawberries for local restaurants and retailers.

Metropolis’s team uses a hydroponic process to grow produce, which means no soil. By being indoors, they avoid weeds that require herbicides. They don’t have much problem with insects, but the few that show up are digested by carnivorous plants. Crops are nourished with chelated minerals, specially filtered water, and other techniques to avoid both animal-based and petroleum-based fertilizers.

It’s a clean operation that puts out fresh product and is attentive to standards. And Jack Griffin, the former Wall Street economist who founded Metropolis, wanted some third-party verification of how far he was going to avoid animal products, pesticides, and basically anything else on the lists of modern consumers’ concerns. Something Like “USDA Certified Organic.”

https://www.instagram.com/p/_ZmmejOH-s/?taken-by=metropolisfarms

The National Organic Standards Board (the advisory body) says that hydroponic operations can’t be organic. But the National Organic Program (the regulatory body) disagrees, and they have certified a handful of hydroponic facilities. Even so, such certification is a rarity, deservedly or not. Besides, for many sophisticated customers, Certified Organic has lost its lustre, with its growing list of permissible pesticides and non-organic substances, accepted practices like de-beaking of chickens, and the general impression that the whole thing is just a big racket. Griffin wanted something more rigorous.

Something like vegan.

“We’ve become a nation of label readers, bottom line,” says Len Torine, director of the American Vegetarian Association. The AVA is among a small number of vegan-certifying organizations with proprietary standards that they hope will help appeal to ever more conscientious consumers. Their distinctive triangular logo can be found emblazoned on vegetarian and vegan products of small food producers and restaurants, and even massive transnationals like Starbucks and Taco Bell are now offering an assortment of AVA-certified products (albeit without displaying AVA’s logo on their packaging and, in Taco Bell’s menus, no items labeled vegan in any way).

While it’s hard to argue that even an officially vegan-certified burrito from Taco Bell would be healthy or ethically produced, AVA’s aim is to indicate to consumers something about the products they buy that ingredients lists won’t. “What the label readers want is transparency, basically. Clarity and honesty. When they see vague things on the label of the product, they’re not sure what it is,” Torine says.

“Vegan” might be as clear a standard as you can imagine: no animal parts or byproducts. Obviously precluded are meat, poultry, fish, dairy, even honey. Serious vegans also eschew things like beers clarified with isinglass (which is made from fish bladders), medication capsules made of collagen-based gelatin, sugar refined with bone char, and so on.

“[Companies] send us samples of the product they want to be certified with a full list of ingredients,” says Torine. “We have a review team, we put the products and ingredients through a very strict compliance review, and if there’s anything, for example, on the label like ‘natural flavors or spices,’ we ask them what that is to verify. If you’re using vitamin D3, we’ve got to know where that comes from, because that usually comes from lanolin, which is vegetarian, not vegan.”

Certifying that a packaged food is free from animal products is one thing. Certifying that produce is raised according to vegan standards is another. The idea is still uncommon. The British organization Vegan Organic Network certifies farms, including some U.S. farms. Though its standards go beyond even what many vegans would require—for example, they not only prohibit the use of manure, they ban the raising of any livestock on the property, the use of compost made from non-organic plants, and the use of any form of artificial fertilizer.

Metropolis Farms is the first U.S. vegan farm to be certified by AVA, and it may be the first farm so certified by a U.S. organization.

“I wanted somebody that was actually going to be more of a guard dog about this,” says Jack Griffin. “We gave [Torine] I think 50 to 60 pages, maybe more, of documentation. He reserves the right to inspect us at will, and close us down if we’re lying or not following his processes. Among other things, we have to wear rubber gloves. Our food isn’t touched by people until it’s harvested.”

Surely, rack-grown basil will satisfy the standards of even the uncompromising level 5 vegan, right? “For every Facebook post or comment that we get, probably one percent comes from somebody who attacks us because we’re not vegan enough because I’ll hire non-vegans,” says Griffin.

Can the AVA be reasonably expected to sniff out carnivores on a farm’s payroll? Not likely, but then how do we decide where the bottom line gets drawn?

Lest you think the use of manure is merely the concern of philosophically purist vegans, consider that some 48 million Americans – about one in six — get food poisoning every year, mostly from leafy greens. The chief culprit is norovirus, carried in bits of manure found on improperly washed food. If vegan certification were to, somehow, expand to include soil protocols, an ethically driven “boutique” standard can have real implications for public health.

This excellent article, written by Carrie Griffin Basas and published in the Utah Law Review, explores the question of whether the government should establish a federal standard for vegan certification. One conclusion she reaches is that vegan is seen as a preferential standard, rather than one that addresses a specific health concern, despite figures like the manure-related illness cited above, which would be avoided if a strictly vegan growing process were enforced.

In the world of packaged goods, FDA has labeling authority. Its purpose is ensuring that consumers aren’t misled about the contents of the food products they buy, that what the box says is what you’ll find in the box. The agency is not interested in whether production processes adhere to particular dietary guidelines. The government, for example, has no role in regulating Kosher or Halal labeling. (Incidentally, the AVA provides vegetarian certification for OU, the country’s largest Kosher certifier.)

If there is ever going to be reliable assurance of “ethically sourced” food, it’s going to come by way of pressure from those who already hold themselves to a higher standard. There are legitimate reasons beyond personal preference for wanting to avoid buying food that has links to factory farms, wasteful shipping routes, pesticides, and, yes, even manure.

“We like to think that we provided the rules and the benchmark standard because there wasn’t anybody else that really did it,” Torine says. “[The guidelines] are still being established—it’s always going to be a work in progress.”

So we now have an additional benchmark. But in the end, is that a good thing? Place your bets, folks. This is just another round in a long, iterative game.

Correction: April 28, 2016. An earlier version of this article listed the vitamin often derived from lanolin as B3. The correct vitamin is D3.