 Now I'm going to talk to you about some rules that you need to follow when you're working with some of the chemicals that you may come across with during the semester. So here we have methanol. This is a type of alcohol. We have a two normal solution of an acid called hydrochloric acid. And we have here what is called glacial acetic acid. This is similar to the acid found in vinegar. And this is ethanol, 100% ethanol that they call anhydrous ethanol. So when working with chemicals like these, you need to always protect yourself. Again, you need to have on your gloves. You need to have on your glasses to protect yourself. So always make sure before you handle any of these chemicals that you'll read the labels properly. So if you notice the labels for these chemicals are located on the front here. And I'm just going to look at acetic acid for example. So this particular chemical, it's an acid. So because of that it is very corrosive. So it could cause extreme burns. So you have to be very careful when handling it. And there are some other guidelines to follow also which you'll find on the bottle. What to do if it actually spills on you. What to do if it gets in your eyes. We'll talk about that later on. So just make sure you look at the labels to know how to handle this particular chemical. When working with volatile chemicals such as 30% formaldehyde, you want to make sure that you work with this chemical underneath the fume hood. Because this is a volatile compound. So the fumes that it may give off at room temperature could directly affect you if you inhale it. So you want to make sure it's under the fume hood so that the vapors will be sucked up by the fume hood instead of attacking you directly. So when you're handling chemicals in general you want to make sure you handle them with care so that you avoid spills. So I'm just going to show you an example of how to handle the chemical using a pipeter with the serological pipeter here and this one is an automatic pipeter. Now note that I'm using a pipeter and not pipeting by mouth. So under no circumstances do not pipet by mouth because these chemicals are dangerous. This formaldehyde in particular is a cancer causing agent. So you gently remove the cover from the bottle. You immerse the pipet into the liquid and you slowly pull the liquid up to the desired volume and then you transfer into your beaker right here. And immediately after you finish using this liquid you close the bottle and you secure your pipet. And here you'll handle this with very little spillage. When you're using let's say you don't need as much of this particular formaldehyde as you had thought you needed even though you have used some and there's some left back you never pour the formaldehyde back into the stock bottle because what you can do is to introduce contaminants back into your stock solution. So that's very important. So when you have utilized your formaldehyde you have to get rid of it but this is one of those chemicals that you don't throw down the sink. Again it's a very carcinogenic agent so you want to make sure you put it in a waste container so you could put it in a container like this. You label what's on the container, what's in the container in this case it would be formaldehyde so that the person who needs to dispose of formaldehyde again will know that this is the container to do this. So it's important for you to put the correct waste in the correct waste container.