I just got back from Greenbuild in San Francisco, and by many accounts it was a big success. There were great speakers, inspiring ideas, interesting new products, and a jolt of energy.

But I started to think about how green the event really was. After all, I probably consumed hundreds of gallons of jet and car fuel getting there. Those presenting must have used even more resources schlepping booths and products across the country. Not to mention, how much electricity is consumed and waste produced during the conference itself?

Greenbuild does have stringent sustainability guidelines for all exhibitors, including a required materials usage report and prohibition of unsustainable products like Styrofoam in exhibits. And the Moscone Center, where it was held, was recently awarded LEED Gold certification. But how much can they really keep waste at bay at a show like this?

So what else wasn’t green about Greenbuild?

The answer came to me from a nonprofit called the Green Building Alliance (the Alliance is a USGBC affiliate, not the organizer of the Greenbuild trade show), which pointed out that many of the companies selling so-called sustainable products at Greenbuild weren’t that green after all. While most companies’ products have eco-positive attributes, many, the Alliance claims, do not disclose hazardous materials. Other manufacturers and organizations are fighting the proposed LEED Building Product Disclosure and Optimization credit, which would reward transparency of material contents and the avoidance of concerning chemicals.

Posted around the conference was the Alliance’s “Transparency Treasure Map,” which pointed out about 25 companies that they considered “transparency leaders,” meaning they disclose all the materials they employ to the public on websites like the Healthy Building Network Directory, Pharos Project, and Health Product Declaration Collaborative. It also labeled about 20 firms—including Alcoa, BASF, and DuPont—as “toxic supporters,” meaning they use dangerous materials or are members of groups like the American Chemistry Council and the Vinyl Institute that actively oppose the proposed LEED material credit or have lobbied against regulations on various hazardous materials.

I’m sure the companies on the “toxic supporters” list would argue that the label isn’t fair, and that few products are completely free of toxicity. But to have so many convincing red flags—particularly the unwillingness to disclose materials—at a show called Greenbuild is more than a little concerning. Sure, it’s great that products at the conference are greener than the industry standard, but that doesn’t make them all that green, does it? Over the course of Greenbuild’s ten years the green building movement has progressed from a group of well-minded environmentalists into a serious money making industry, and inevitably there are some who will put profit over ideology. The plethora of green product certifications and their various guidelines only make finding them more confusing.

I believe getting the message out about sustainability and sharing new green innovations outweighs the negative environmental impact of putting on the tradeshow. I also think it’s good that so many companies are focusing on sustainability. But we do have to question how green the green architecture products at the show really are, and why so many companies are hesitant to disclose what materials they’re employing. Yes, the USGBC should pass its LEED Building Product Disclosure and Optimization credit. But it’s up to not just the USGBC but to the AIA and anyone else involved in the building industry to watch these products carefully. If there are this many problem materials at Greenbuild, just think how many there are in the rest of the world.