1 00:00:01,800 --> 00:00:07,560 Speaker 1: Welcome to brainstuffe A production of iHeart Radio, Hey brain stuff, 2 00:00:07,600 --> 00:00:12,320 Speaker 1: Lauren bobabam here. Whatever color your clothes are, the process 3 00:00:12,360 --> 00:00:16,079 Speaker 1: to make them that way is probably pretty toxic. According 4 00:00:16,160 --> 00:00:19,680 Speaker 1: to the United Nations Environment Assembly, textile dying is the 5 00:00:19,720 --> 00:00:23,640 Speaker 1: second largest water polluter in the world, and not only 6 00:00:23,720 --> 00:00:27,200 Speaker 1: is the dyeing process rife with harmful chemicals, it's very 7 00:00:27,240 --> 00:00:30,520 Speaker 1: water intensive. Your average pair of jeans takes up to 8 00:00:30,520 --> 00:00:33,239 Speaker 1: twenty six gallons. That's a hundred liters of water to 9 00:00:33,320 --> 00:00:37,159 Speaker 1: die in. These days of fast fashion, our hunger for 10 00:00:37,200 --> 00:00:40,440 Speaker 1: trendy clothes is directly harming us and a lot of 11 00:00:40,440 --> 00:00:44,960 Speaker 1: other organisms and ecosystems all over the world. The denim 12 00:00:45,000 --> 00:00:48,440 Speaker 1: industry alone uses over forty five thousand tons of synthetic 13 00:00:48,479 --> 00:00:51,479 Speaker 1: indigo a year, more than eighty four thousand tons of 14 00:00:51,479 --> 00:00:54,800 Speaker 1: sodium hydro sulfite and fifty three thousand tons of lie. 15 00:00:54,920 --> 00:00:58,600 Speaker 1: According to scientists at the University of Georgia, this adds 16 00:00:58,680 --> 00:01:02,680 Speaker 1: up to a big environmental problem. However, a research team 17 00:01:02,720 --> 00:01:06,000 Speaker 1: at that university has worked out a solution that eliminates 18 00:01:06,000 --> 00:01:09,280 Speaker 1: noxious chemicals from the denim dyeing process while using a 19 00:01:09,360 --> 00:01:14,440 Speaker 1: fraction of the water, but let's back up a step back. 20 00:01:14,480 --> 00:01:17,920 Speaker 1: In the seventeen hundreds, indigo, the plant that historically gave 21 00:01:18,000 --> 00:01:21,399 Speaker 1: denim that iconic blue color, was a major export of 22 00:01:21,440 --> 00:01:25,160 Speaker 1: the American colonies. These days, however, we die our blue 23 00:01:25,240 --> 00:01:28,360 Speaker 1: jeans with synthetic indigo pigment, which is why you can 24 00:01:28,400 --> 00:01:31,479 Speaker 1: buy a pair of jeans for fifteen bucks. But no 25 00:01:31,520 --> 00:01:35,000 Speaker 1: matter whether the indigo is natural or synthetic, the process 26 00:01:35,040 --> 00:01:38,479 Speaker 1: of dying denom requires a strong reducing agent to make 27 00:01:38,520 --> 00:01:42,440 Speaker 1: the dye dissolve in water. For the article of this 28 00:01:42,480 --> 00:01:45,360 Speaker 1: episode is based on how Stuff Works. Spoke with Sergei Minko, 29 00:01:45,720 --> 00:01:47,760 Speaker 1: a co author of the study and a professor in 30 00:01:47,760 --> 00:01:50,480 Speaker 1: the College of Family and Consumer Sciences at the University 31 00:01:50,520 --> 00:01:54,920 Speaker 1: of Georgia. He said, the commercial technology for dyeing textiles 32 00:01:55,040 --> 00:01:59,800 Speaker 1: uses aggressive chemicals. For denim, a strong toxic reducing agent, 33 00:02:00,000 --> 00:02:03,920 Speaker 1: old sodium hydrosulfite is used to make it soluble. Some 34 00:02:04,000 --> 00:02:06,720 Speaker 1: amount of this reducing agent is used in each stage 35 00:02:06,760 --> 00:02:10,240 Speaker 1: of a repeating process anywhere from five to ten times 36 00:02:10,280 --> 00:02:15,160 Speaker 1: if they want to get an intense shade. And as 37 00:02:15,160 --> 00:02:18,120 Speaker 1: we said, this process uses a huge amount of water. 38 00:02:18,720 --> 00:02:20,919 Speaker 1: A pair of genes can take up to two thousand 39 00:02:20,960 --> 00:02:25,080 Speaker 1: gallons to produce, and that's about once you consider the 40 00:02:25,080 --> 00:02:27,639 Speaker 1: water it takes to grow the cotton, dye the fabric, 41 00:02:27,760 --> 00:02:31,560 Speaker 1: and manufacture the pants. Not only that, but many of 42 00:02:31,600 --> 00:02:35,240 Speaker 1: the chemicals involved in denim dyeing don't degrade in the environment. 43 00:02:36,040 --> 00:02:39,320 Speaker 1: While the technology does exist to filter the toxic chemicals 44 00:02:39,320 --> 00:02:41,160 Speaker 1: out of the water before it hits a river or 45 00:02:41,160 --> 00:02:43,600 Speaker 1: a stream, many of the places in the world where 46 00:02:43,600 --> 00:02:47,200 Speaker 1: garment production happens at China and Bangladesh, for instance, don't 47 00:02:47,200 --> 00:02:50,160 Speaker 1: require the infrastructure to remove the chemicals from the water 48 00:02:50,320 --> 00:02:54,360 Speaker 1: before it contaminates waterways and ends up poisoning wildlife people 49 00:02:54,600 --> 00:02:59,320 Speaker 1: in crops. Minko said. Some of the environments where they 50 00:02:59,360 --> 00:03:03,280 Speaker 1: die text ills, everything is artificially colored in different shades. 51 00:03:04,000 --> 00:03:07,040 Speaker 1: Of course, the major damage doesn't come from the dyes themselves, 52 00:03:07,160 --> 00:03:11,200 Speaker 1: but high salt concentrations and these reducing agents, which can 53 00:03:11,240 --> 00:03:16,840 Speaker 1: be very aggressive in ecosystems. So let's talk about the 54 00:03:16,880 --> 00:03:19,720 Speaker 1: new denom dying method that the researchers came up with. 55 00:03:20,400 --> 00:03:24,799 Speaker 1: This process mixes cellulose nanoparticles called kitisen that are made 56 00:03:24,800 --> 00:03:28,519 Speaker 1: from wood pulp with natural indigo dye. Although the researchers 57 00:03:28,520 --> 00:03:32,320 Speaker 1: believe synthetic dies could also be used. This mixture creates 58 00:03:32,320 --> 00:03:34,160 Speaker 1: a sort of gel that can be applied to the 59 00:03:34,160 --> 00:03:37,480 Speaker 1: fabric a single time to yield an intense indigo color, 60 00:03:37,960 --> 00:03:41,280 Speaker 1: compared with the multiple dip process of conventional dyeing that 61 00:03:41,360 --> 00:03:44,000 Speaker 1: requires up to ten applications of dye to yield a 62 00:03:44,080 --> 00:03:48,760 Speaker 1: dark shade. The kitisen essentially glues the pigment in place 63 00:03:48,880 --> 00:03:52,000 Speaker 1: after the fabric dries, creating a sort of matrix of 64 00:03:52,120 --> 00:03:55,320 Speaker 1: dye that coats the fibers of the denom. Because this 65 00:03:55,360 --> 00:03:58,960 Speaker 1: process doesn't involve dissolving the indigo dye, and no reducing 66 00:03:59,000 --> 00:04:02,320 Speaker 1: agents are necessary, thus cutting the amount of water used 67 00:04:02,320 --> 00:04:07,320 Speaker 1: in conventional dyeing methods by about nine Not only that, 68 00:04:07,360 --> 00:04:10,240 Speaker 1: but the process is non toxic, the drying time for 69 00:04:10,240 --> 00:04:13,160 Speaker 1: the kitis and dye is shorter, and the new technique 70 00:04:13,240 --> 00:04:16,560 Speaker 1: yields fabric of the same weight, thickness, and overall feel 71 00:04:16,640 --> 00:04:21,000 Speaker 1: as traditionally died denim. Here's hoping that more research can 72 00:04:21,000 --> 00:04:23,960 Speaker 1: bring this new fabric technology out of the lab and 73 00:04:24,200 --> 00:04:32,120 Speaker 1: into practice. Today's episode is based on the article A 74 00:04:32,200 --> 00:04:34,920 Speaker 1: New Green Solution for dyeing blue denim on how to 75 00:04:35,080 --> 00:04:38,120 Speaker 1: works dot Com, written by Jesslin Shields. Brain Stuff is 76 00:04:38,160 --> 00:04:40,560 Speaker 1: production of iHeart Radio in partnership with how stuff works 77 00:04:40,560 --> 00:04:43,280 Speaker 1: dot com, and it's produced by Tyler Klang. For more 78 00:04:43,279 --> 00:04:46,799 Speaker 1: podcasts my heart Radio, visit the iHeart Radio app, Apple Podcasts, 79 00:04:46,839 --> 00:04:48,640 Speaker 1: or wherever you listen to your favorite shows.