1 00:00:02,040 --> 00:00:07,000 Speaker 1: Welcome to brain Stuff from how Stuff Works, Hey, brain Stuff, 2 00:00:07,080 --> 00:00:09,640 Speaker 1: Lauren vocal bomb here. What do you get when you 3 00:00:09,680 --> 00:00:14,080 Speaker 1: combine two molecules of hydrogen and two molecules of oxygen, Well, 4 00:00:14,160 --> 00:00:16,520 Speaker 1: you get H two O two. More commonly known as 5 00:00:16,600 --> 00:00:20,480 Speaker 1: hydrogen peroxide, used in all kinds of industries from food 6 00:00:20,480 --> 00:00:24,840 Speaker 1: processing to papermaking, two textiles to electronics, peroxide is a 7 00:00:24,920 --> 00:00:28,760 Speaker 1: great disaffecting and bleaching agent. It's clear and colorless, and 8 00:00:28,840 --> 00:00:31,680 Speaker 1: when poured over an open wound, peroxide will kill many 9 00:00:31,720 --> 00:00:36,200 Speaker 1: types of microorganisms. It's also an extremely stable compound when 10 00:00:36,400 --> 00:00:39,960 Speaker 1: properly stored, which is why when you buy hydrogen peroxide 11 00:00:40,080 --> 00:00:44,080 Speaker 1: it usually comes in a brown plastic bottle. Here's why 12 00:00:44,720 --> 00:00:48,440 Speaker 1: many chemical compounds break down over time, and hydrogen peroxide 13 00:00:48,479 --> 00:00:52,080 Speaker 1: is no exception. Although it is extremely stable, the solution 14 00:00:52,159 --> 00:00:54,760 Speaker 1: can start to decompose when it comes in contact with 15 00:00:54,920 --> 00:00:58,160 Speaker 1: light and heat. The brown bottle in your medicine cabinet 16 00:00:58,200 --> 00:01:01,480 Speaker 1: is a bulwark against those two cattle lists. Light cannot 17 00:01:01,480 --> 00:01:04,880 Speaker 1: penetrate the tint of the brown bottle, preventing oxidation, which 18 00:01:04,920 --> 00:01:07,160 Speaker 1: you want to prevent because it can result in an 19 00:01:07,160 --> 00:01:11,440 Speaker 1: increase in temperature as peroxide breaks down. It gets hotter. 20 00:01:11,959 --> 00:01:15,919 Speaker 1: As a result, the compounds decomposition rate accelerates. In fact, 21 00:01:15,959 --> 00:01:19,880 Speaker 1: for every ten degree fahrenheit rise in temperature, the decomposition 22 00:01:19,959 --> 00:01:23,520 Speaker 1: rate nearly doubles, meaning that around seventy two degrees fahrenheit 23 00:01:23,560 --> 00:01:26,280 Speaker 1: that's about twenty two celsius, it decomposes at a rate 24 00:01:26,319 --> 00:01:29,080 Speaker 1: of one percent per year. But if it got up 25 00:01:29,120 --> 00:01:32,759 Speaker 1: to one fifty one degrees fahrenheit that's about sixty six celsius, 26 00:01:32,920 --> 00:01:34,839 Speaker 1: it would be decomposing at a rate of one percent 27 00:01:34,959 --> 00:01:37,520 Speaker 1: per week. By the time it hit the boiling point 28 00:01:37,560 --> 00:01:40,120 Speaker 1: of water, it would be going at nearly two percent 29 00:01:40,400 --> 00:01:45,360 Speaker 1: per day. Moreover, some sort of contaminants such as dust, silver, lead, 30 00:01:45,520 --> 00:01:48,040 Speaker 1: or another metal, gets into the solution, it can spark 31 00:01:48,080 --> 00:01:52,320 Speaker 1: a fire. Although the solution itself is not explosive. Those 32 00:01:52,360 --> 00:01:55,640 Speaker 1: in the industry must handle hydrogen peroxide with care. If 33 00:01:55,680 --> 00:01:57,680 Speaker 1: the solution is in a closed system, such as a 34 00:01:57,720 --> 00:02:00,200 Speaker 1: storage tank, and it starts to break down, press share 35 00:02:00,280 --> 00:02:02,800 Speaker 1: can build up, causing the tank or a pipe or 36 00:02:02,880 --> 00:02:05,919 Speaker 1: line to rupture. The good news is that the bottle 37 00:02:05,960 --> 00:02:08,640 Speaker 1: of peroxide in your medicine cabinet only contains about a 38 00:02:08,680 --> 00:02:12,800 Speaker 1: three percent solution, far less than that the food industry uses, 39 00:02:12,840 --> 00:02:16,600 Speaker 1: for example. You may also notice the peroxide never comes 40 00:02:16,639 --> 00:02:20,000 Speaker 1: in a clear glass container. That's because glass bottles may 41 00:02:20,000 --> 00:02:23,960 Speaker 1: contain dissolved alkali metal ions that can react with the solution. 42 00:02:29,080 --> 00:02:31,880 Speaker 1: Today's episode was written by John Paritano and produced by 43 00:02:31,919 --> 00:02:35,200 Speaker 1: Tyler Klang. Speaking of containers, you can find some with 44 00:02:35,240 --> 00:02:38,200 Speaker 1: the brainstuff logo and other designs in our online shop 45 00:02:38,240 --> 00:02:41,880 Speaker 1: at t public dot com slash Brainstuff, and of course, 46 00:02:42,080 --> 00:02:45,000 Speaker 1: for more on this and lots of other carefully handled topics, 47 00:02:45,160 --> 00:02:58,840 Speaker 1: visit our home planet, has stuff works dot com.