Lesson 5: Precautions
Safe Handling of Acids and Bases
There are a number of proper procedures for the safe handling of acids and bases that you need to know because you will be working with them quite a bit. (These guidelines are also listed in example 1 of your workbook.)
- Know what you are working with; pay attention not only to the name (or formula) of the chemical but also to the concentration.
- Pick up dropper bottles by the bottle, not by the dropper. Use only the dropper that comes with the bottle; do not contaminate the contents by switching droppers between different bottles.
- Both acids and bases can be corrosive to human tissue. When concentrated, they can react with tissue and break it down. In general, the more concentrated the acid or base happens to be, the more hazardous it is. Although the more concentrated acids and bases are the most dangerous ones, don't ignore the dilute ones.
- You must be particularly careful about getting them in your eyes. The best way to avoid this is to wear safety glasses or goggles when handling either acids or bases. If you do get any in your eyes, let the instructor know and flush it out immediately with lots of water, several minutes worth. There are eye washes in the lab. If you have not yet learned where they are, and how to use them, ask for instructions now or the next time you are in the lab.
- Suppose you get some acid or base on you, other than in your eyes. The procedure is the essentially the same: flush that area immediately for several minutes with water and consult the instructor for further advice. If you should be unfortunate enough to spill it all over you, use the safety shower in the lab.
- If you spill acid or base on the lab bench top or on the floor, treat it immediately. If it is an acid, first neutralize it with sufficient sodium bicarbonate, (commonly known as baking soda). We have some readily available in the lab or in the adjoining prep room. When the baking soda no longer bubbles when you work it into the spill, the acid is neutralized and you can clean up the mess. If it's a base, you can neutralize it with some vinegar, which is dilute acetic acid. In any case, clean up the area thoroughly. We also have spill kits for use with extensive spills.
- Disposal: The quantities and concentrations of acids and bases used in the exercises and demonstrations in this lesson are permissible to flush down the drain. However, the quantity involved in a spill should be neutralized before disposal.