The cavernous hangers of Berlin’s Tempelhof Airport, Europe’s biggest building, are buzzing once again. This week, loud beats, wailing guitars and the murmur of fashion business banter fill the empty halls which once resounded with propellers and engines. Bread & Butter, a trade fair for urban street wear, is running until Friday, featuring global names like Adidas, Levi’s and Bench, as well as many up-and-coming labels from across Europe.

Outside, shiny black shuttle buses whizz visiting fashionistas across town, taking them to Berlin Fashion Week’s glossy shows and launch parties. But of the thousands of people checking out the latest trends, only a few pause to consider where and how the clothes were made.

That, though, is something Frans Prins, founder of a green fashion event TheKey.to, wants to change. From a spacious former bakery in a gritty corner of Kreuzberg, he has created a three-day event which seeks to ask the questions which are all too often overlooked during big fashion events.

“For a long time people have known about child labor and sweat shops. Now there is a rising awareness of pesticide use in cotton production,” Prins told SPIEGEL ONLINE. “People are increasingly asking where their clothes come from.”

Global cotton production is responsible for a significant percentage of pesticides and insecticides used worldwide, he said. “And the chemicals they use in the south were often banned in Europe years ago,” he adds. “The effects are that drinking water is contaminated and land is damaged.”

Now in its second year, TheKey.to, is hosting green fashion networking events, workshops and talks including a speech by Renate Künast, head of the German Green Party. Among the 50 labels showcased at the event, just under half come from outside Germany. Its organizers expect up to 3,000 visitors. Of course it is dwarfed by its glossier counterparts like Fashion Week and Bread & Butter, but Prins argues that the issue of green fashion is growing in influence.

“My prediction is that this will go mainstream. More brands and labels will go green,” he said. “At first people said that it would just last one season. But it is here to stay.”

And there are signs that organic and fair-trade clothing has crept onto the radar screen of many big firms. H&M, Levi’s and C&A are among a list of major retailers whose ranges include organic cotton items.

A gradual switch towards organic cotton is also evident from the fact that it used to make up less than 1 percent of the cotton sold globally, whereas now it makes up around 5 percent, Prins said.