 | First, never handle any laboratory chemicals with your fingers--some stain, and some are
corrosive. Instead, for the solids you can use a clean
scoop.
|
| Whenever you remove the lid of a bottle containing a chemical (whether it's a solid or a
liquid), either hold the stopper or lid in your hand or put it upside down on the counter
to avoid contaminating the stopper or lid, which in turn would contaminate the chemical in
the bottle. Of course, a dirty lab scoop will certainly contaminate the bottle. To be sure
the lab scoop is clean, always wash and dry it before you use it.
|
| Another technique for transferring solid chemicals is to pour from the bottle onto a
folded piece of paper and then pour it from the paper into the test tube (or whatever
container you are using). In that way you avoid contaminating the chemical in the bottle.
Once you have removed a chemical from a bottle, you should replace the lid securely. Also,
do not return chemicals to a bottle once you have removed them. It's better to waste a
little bit of that material than to waste the whole bottle because it has been
contaminated. A corollary to this is to not take any more chemical than you need. You can
always take more later if you need it.
|
| When disposing of used chemicals, first look for special "waste" containers
designated for that chemical. In the absence of a special container, put solids that don't
dissolve in water into the wastebasket, not the sink. That includes matches. Don't throw
matches in the sink. Make sure they are out, wet them, and then look for a container that
says "used matches"; there will often be one on the counter near the burners.
|
| Liquids and solids that are soluble in
water can sometimes be disposed of in the sink, and washed down with plenty of water. But
first check to see if there is a special waste container for them. Ask the instructor if
you aren't sure what to do with a particular chemical.
|
| Of course, be sure to wash out all your equipment so that the next person doesn't have
to start with a big mess. |
