1 00:00:01,920 --> 00:00:06,400 Speaker 1: Welcome to brain Stuff, a production of iHeart Radio Pay 2 00:00:06,440 --> 00:00:11,200 Speaker 1: brain Stuff Lauren Bogle bomb here. The fertilizer explosions that 3 00:00:11,240 --> 00:00:14,840 Speaker 1: have killed hundreds and injured thousands of residents in unfortunate 4 00:00:14,880 --> 00:00:18,680 Speaker 1: cities like Lebanon, Beirut, Breast, France, and Texas City in 5 00:00:18,720 --> 00:00:22,800 Speaker 1: the US are notable not only for their terrible outcomes, 6 00:00:22,800 --> 00:00:26,599 Speaker 1: but also because explosions from fertilizer manufacturing and storage are 7 00:00:26,720 --> 00:00:31,120 Speaker 1: relatively rare occurrences. For a planet that uses about two 8 00:00:31,240 --> 00:00:36,440 Speaker 1: hundred million tons of fertilizer a year, accidents are not ubiquitous. However, 9 00:00:36,680 --> 00:00:40,520 Speaker 1: when ammonium nitrate, the compound linked to all of these disasters, 10 00:00:40,720 --> 00:00:45,440 Speaker 1: does blow up, the effects can be devastating. On April six, 11 00:00:45,840 --> 00:00:49,199 Speaker 1: ninety seven, about filled with twenty three hundred tons of 12 00:00:49,200 --> 00:00:52,479 Speaker 1: ammonium nitrate and doctor near Texas City blew up as 13 00:00:52,520 --> 00:00:55,560 Speaker 1: the result of a small fire on board. Nearly six 14 00:00:55,680 --> 00:01:00,400 Speaker 1: hundred people were killed. That seven incident is ill one 15 00:01:00,400 --> 00:01:04,600 Speaker 1: of the worst industrial accidents in US history. The tragedy 16 00:01:04,600 --> 00:01:07,520 Speaker 1: in Lebanon in August has caused at least two d 17 00:01:07,640 --> 00:01:10,280 Speaker 1: and twenty deaths and five thousand injuries, and has left 18 00:01:10,280 --> 00:01:13,760 Speaker 1: and estimated three hundred thousand people without homes. It was 19 00:01:13,800 --> 00:01:16,679 Speaker 1: caused by some three thousand tons of ammonium nitrate exploding. 20 00:01:18,400 --> 00:01:21,759 Speaker 1: So how do fertilizers, which we often think of as 21 00:01:21,920 --> 00:01:25,960 Speaker 1: natural compounds that are good for the earth, explode so violently. 22 00:01:27,400 --> 00:01:31,240 Speaker 1: Let's begin with a little background on fertilizer itself. Plants 23 00:01:31,280 --> 00:01:33,760 Speaker 1: need a few basic nutrients to grow, and most of 24 00:01:33,800 --> 00:01:35,800 Speaker 1: them are found in the air and water and things 25 00:01:35,840 --> 00:01:39,760 Speaker 1: like oxygen, carbon, and hydrogen. Of course, they also need 26 00:01:39,800 --> 00:01:42,240 Speaker 1: some other elements that may or may not be rich 27 00:01:42,280 --> 00:01:45,800 Speaker 1: in the soil that they're growing in. If a plant 28 00:01:45,880 --> 00:01:48,000 Speaker 1: just needs a little bit of a nutrient, it's called 29 00:01:48,040 --> 00:01:51,760 Speaker 1: a micronutrient, think a boron or chlorine. If a plant 30 00:01:51,760 --> 00:01:57,080 Speaker 1: needs heaps of an ingredient, it's called a macronutrient, think nitrogen, phosphorus, potassium, 31 00:01:57,120 --> 00:02:02,320 Speaker 1: and sulfur. And that's where fertilizer comes in. It packs 32 00:02:02,360 --> 00:02:04,960 Speaker 1: the dirt with the secondary elements needed to make a 33 00:02:05,040 --> 00:02:08,560 Speaker 1: plant flourish. Of course, many of us home gardeners would 34 00:02:08,560 --> 00:02:11,880 Speaker 1: simply classify good old manure as fertilizer, and we wouldn't 35 00:02:11,919 --> 00:02:16,320 Speaker 1: be wrong. According to the International Fertilizer Industry Association, any 36 00:02:16,440 --> 00:02:21,320 Speaker 1: natural or manufactured material that contains at least five percent nitrogen, potassium, 37 00:02:21,400 --> 00:02:26,000 Speaker 1: or phosphorus counts as a fertilizer. Of course, the fertilizing 38 00:02:26,040 --> 00:02:29,480 Speaker 1: manufacturing industry produces synthetic or as they prefer to call them, 39 00:02:29,480 --> 00:02:35,480 Speaker 1: mineral fertilizers. To manufacture mineral fertilizers, there are a few steps. First, 40 00:02:35,520 --> 00:02:38,520 Speaker 1: you must collect the materials, which are in fact found 41 00:02:38,560 --> 00:02:41,400 Speaker 1: in nature. Then you have to treat them to bolster 42 00:02:41,520 --> 00:02:45,240 Speaker 1: the concentration or refine the products. After that you must 43 00:02:45,240 --> 00:02:47,840 Speaker 1: convert them into a form that can be used by plants, 44 00:02:48,160 --> 00:02:51,000 Speaker 1: and then you may want to combine those nutrients with others. 45 00:02:52,480 --> 00:02:56,799 Speaker 1: One of the main components in manufactured fertilizer is ammonium nitrate. 46 00:02:57,480 --> 00:03:00,280 Speaker 1: Like we said, nitrogen is one of those macronuts rents 47 00:03:00,320 --> 00:03:04,080 Speaker 1: that plants love, so a lot of fertilizers are nitrogen based. 48 00:03:05,120 --> 00:03:07,880 Speaker 1: Of course, we can't just bottle up some nitrogen and 49 00:03:08,000 --> 00:03:11,480 Speaker 1: pour it on the old carrot patch. Atmospheric nitrogen has 50 00:03:11,560 --> 00:03:15,200 Speaker 1: a really strong chemical bond that plants can't easily break, 51 00:03:15,600 --> 00:03:19,399 Speaker 1: So fertilizer companies create nitrogen based substances that are much 52 00:03:19,440 --> 00:03:23,040 Speaker 1: easier for plants to take. Apart ammonium nitrate is one 53 00:03:23,080 --> 00:03:26,800 Speaker 1: such compound, and it's used for good reason. The ammonium 54 00:03:26,840 --> 00:03:30,120 Speaker 1: part sticks around longer without evaporating, so it's great for 55 00:03:30,200 --> 00:03:33,280 Speaker 1: hot summer fields, and the nitrate is easily used by 56 00:03:33,320 --> 00:03:37,880 Speaker 1: plants even more compelling in the agricultural industry. It's inexpensive 57 00:03:37,920 --> 00:03:41,400 Speaker 1: to manufacture. You can bine ammonia and nitric acid and 58 00:03:41,440 --> 00:03:46,200 Speaker 1: you're done. But what makes ammonium nitrate capable of such 59 00:03:46,360 --> 00:03:52,000 Speaker 1: lethal explosions? Perhaps, surprisingly not much. Ammonium nitrate is a 60 00:03:52,040 --> 00:03:56,320 Speaker 1: relatively stable compound, according to the US Environmental Protection Agency. 61 00:03:56,440 --> 00:03:59,840 Speaker 1: In other words, when it's just sitting quietly somewhere, ammonium 62 00:03:59,880 --> 00:04:02,360 Speaker 1: n trait isn't that big of a problem because it 63 00:04:02,400 --> 00:04:06,320 Speaker 1: needs a relatively high activation energy, that is, the energy 64 00:04:06,360 --> 00:04:11,040 Speaker 1: needed to cause a chemical reaction in order to explode. However, 65 00:04:11,320 --> 00:04:14,880 Speaker 1: if an accident where some sort of detonation, a spark, 66 00:04:15,000 --> 00:04:18,040 Speaker 1: or some other kind of energy occurs, you better believe 67 00:04:18,080 --> 00:04:21,800 Speaker 1: that ammonium nitrate is deadly. The compound essentially makes its 68 00:04:21,800 --> 00:04:26,360 Speaker 1: own fuel from the ammonium and oxidizer the nitrate, so 69 00:04:26,600 --> 00:04:31,679 Speaker 1: its reaction is violent and long lasting. So it makes 70 00:04:31,720 --> 00:04:34,320 Speaker 1: sense that a fire seems to be the cause and 71 00:04:34,400 --> 00:04:37,159 Speaker 1: not the outcome of what happened in all of these 72 00:04:37,160 --> 00:04:42,680 Speaker 1: tragic explosions. It's worth repeating that although ammonium nitrate and 73 00:04:42,720 --> 00:04:47,040 Speaker 1: other fertilizer explosions are terrible, they're rare, but would be 74 00:04:47,120 --> 00:04:50,279 Speaker 1: remiss to not mention that fertilizer can also make a 75 00:04:50,320 --> 00:04:54,640 Speaker 1: deadly intentional weapon. Timothy McVeigh, for one, used a fertilizer 76 00:04:54,640 --> 00:05:03,200 Speaker 1: bomb in Oklahoma City bombing m Today's episode was written 77 00:05:03,240 --> 00:05:05,960 Speaker 1: by Kate Kirshner and produced by Tyler Clang. For more 78 00:05:05,960 --> 00:05:07,799 Speaker 1: on this and lots of other topics, visit how stuff 79 00:05:07,800 --> 00:05:10,200 Speaker 1: works dot com. Brain Stuff is production of I Heart 80 00:05:10,279 --> 00:05:12,720 Speaker 1: Radio or more podcasts. For my heart Radio, visit the 81 00:05:12,760 --> 00:05:15,360 Speaker 1: I Heart Radio app, Apple Podcasts, or wherever you listen 82 00:05:15,400 --> 00:05:16,279 Speaker 1: to your favorite shows.