1
00:00:02,040 --> 00:00:09,760
Speaker 1: Welcome to brain Stuff from How Stuff Works. Hi, I'm

2
00:00:09,840 --> 00:00:13,119
Speaker 1: Christian Sager. This is brain stuff And today's question is

3
00:00:13,480 --> 00:00:16,320
Speaker 1: what is silica gel? And why do I find little

4
00:00:16,360 --> 00:00:19,920
Speaker 1: packets of it in so many things? I mean, that's weird, right,

5
00:00:20,239 --> 00:00:22,599
Speaker 1: Why would my new boots and my beef jerky be

6
00:00:22,720 --> 00:00:26,960
Speaker 1: packed with the same stuff. Silica or more precisely, silicon

7
00:00:27,120 --> 00:00:30,880
Speaker 1: dioxide is the same stuff that quartz in sand are

8
00:00:30,920 --> 00:00:34,040
Speaker 1: made of. It's a desiccant, meaning it adds orbs and

9
00:00:34,159 --> 00:00:38,519
Speaker 1: holds water vapor. And that's ads orbs with an ad

10
00:00:38,560 --> 00:00:43,480
Speaker 1: not absorbs. When we say that something ads orbs moisture,

11
00:00:43,720 --> 00:00:46,599
Speaker 1: we mean that water molecules adhere to the surface of

12
00:00:46,640 --> 00:00:49,440
Speaker 1: the material. Think of the way that sand can seem

13
00:00:49,479 --> 00:00:52,159
Speaker 1: to soak up water. The water is really just adhering

14
00:00:52,200 --> 00:00:55,760
Speaker 1: to each grain. Basically, silica gel does the same thing.

15
00:00:56,160 --> 00:01:00,240
Speaker 1: It's covered in millions of tiny pores that can retain moisture.

16
00:01:00,000 --> 00:01:03,800
Speaker 1: It can actually adds orb about forty of its weight

17
00:01:03,840 --> 00:01:06,959
Speaker 1: in moisture and can thus reduce the relative humidity in

18
00:01:07,000 --> 00:01:11,360
Speaker 1: a closed container down to around So you'll find silica

19
00:01:11,440 --> 00:01:14,560
Speaker 1: gel packs and anything that would be affected by excess moisture.

20
00:01:14,920 --> 00:01:17,080
Speaker 1: It's in with leather products, where it can limit the

21
00:01:17,080 --> 00:01:19,960
Speaker 1: growth of mold. You'll see it packaged with electronics to

22
00:01:20,040 --> 00:01:24,640
Speaker 1: reduce condensation, and because silica gel is nearly harmless, you'll

23
00:01:24,680 --> 00:01:28,480
Speaker 1: find it preventing spoilage in foods like pepperoni. You still

24
00:01:28,520 --> 00:01:30,520
Speaker 1: don't want to eat it, though. If you emptied out

25
00:01:30,520 --> 00:01:33,199
Speaker 1: a packet and ate the beads, they would begin adsorbing

26
00:01:33,280 --> 00:01:36,160
Speaker 1: moisture from your tongue, gums, and the rest of your mouth.

27
00:01:36,440 --> 00:01:38,960
Speaker 1: Your first instinct would probably be to spit it out.

28
00:01:39,280 --> 00:01:43,080
Speaker 1: But if you did swallow it, well, okay, probably you'd

29
00:01:43,080 --> 00:01:45,880
Speaker 1: be fine. But not all silica gel is the same.

30
00:01:46,200 --> 00:01:50,080
Speaker 1: Some has a toxic coating of cobalt chloride. Swallowing this

31
00:01:50,120 --> 00:01:54,040
Speaker 1: stuff probably won't kill you, but it might cause nausea, vomiting,

32
00:01:54,080 --> 00:01:57,600
Speaker 1: and a few other less than awesome symptoms. And when

33
00:01:57,600 --> 00:02:01,080
Speaker 1: it comes to keeping things dry, silica gel works pretty well,

34
00:02:01,200 --> 00:02:04,120
Speaker 1: which is why it's so widespread. It's also found in

35
00:02:04,240 --> 00:02:08,480
Speaker 1: vitamin containers, industrial air systems, and oddly enough, containers of

36
00:02:08,520 --> 00:02:11,720
Speaker 1: cat litter. And this stuff is reusable. You can dry

37
00:02:11,760 --> 00:02:13,720
Speaker 1: it out by heating it in an oven at about

38
00:02:13,720 --> 00:02:17,880
Speaker 1: three hundred degrees fahrenheit. That's about one fifty degrees celsius,

39
00:02:18,240 --> 00:02:20,800
Speaker 1: and people have found all sorts of ways to reuse it.

40
00:02:20,840 --> 00:02:23,480
Speaker 1: There might be too many to list. I mean, all right,

41
00:02:23,560 --> 00:02:26,480
Speaker 1: I guess I can try. Here. It goes protecting papers

42
00:02:26,480 --> 00:02:31,280
Speaker 1: from humidity, drying flowers, preventing rust on tools, preventing condensation

43
00:02:31,320 --> 00:02:35,200
Speaker 1: on windows and inside picture frames, preserving art in display cases,

44
00:02:35,520 --> 00:02:41,080
Speaker 1: mitigating small spills in luggage, slowing silver tarnishing, stopping seed mold,

45
00:02:41,400 --> 00:02:48,760
Speaker 1: and preventing camera lens from fog. Check out the brain

46
00:02:48,760 --> 00:02:50,920
Speaker 1: stuff channel on YouTube, and for more on this and

47
00:02:51,000 --> 00:03:07,520
Speaker 1: thousands of other topics, visit how stuff works dot com