Guidelines for care & Use of Dry Solvent Stills [Example]

any aqueous solutions whatsoever of mercuric salts in any of these storage containers (i.e. mercuric
chloride, mercurous nitrate, etc.) Mercuric salts, either Hg 1+ or Hg 2+ , cannot presently be taken
by waste companies. We will have to store the evaporated remnants of these solutions in a labeled
container, kept in the solvent room #20, until we can either recycle them or receive clear instructions from
higher waste authorities. Be sure to read the Forsyth County/City of Winston-Salem ordinance disallowing
drain disposal of metal cations above specific concentration levels, located in subchapter # 11, below. You
should also read section 7.D.3.8, “Inorganic Ions”, of Prudent Practices, 2nd edition., pages 166-171.
For all other waste handling and disposal involving freshman student labs please follow the
guidelines listed under the “Chemical Handling” section of the modular laboratory student handouts,
instruction‟s information section. The teacher will give this information to you.
Organic chemistry Teaching Assistants will gather student waste containers located in the rear of
their assigned teaching laboratory rooms and take them to the solvent room, #20, for storage on the metal
table. If each container is properly labeled before the experiment starts, you will not have to sort out the
waste into new containers afterwards. Remember, the prep persons are responsible for dispensing
chemicals and waste containers to your assigned area, but you are responsible for removing the waste to the
solvent room, room #20, downstairs. Generally, most benign organic solids used in the undergrad Organic
Labs can be mixed in the same container. When in doubt, check with your instructor or the laboratory
manager.
DO NOT MIX (OR ALLOW UNDERGRADS TO MIX) AQUEOUS SOLUTIONS WITH
ORGANIC SOLVENTS, SOLIDS WITH LIQUIDS, OR OTHERWISE INCOMPATIBLE CHEMICALS
IN THE SAME CONTAINER. These organic lab is equipped with a large, 2-liter, separatory funnel. If
students have trouble separating aqueous and organic waste, have them pour their liquid waste into these
funnels. At the end of the experiment, pour out the bottom layer of water and, if the aqueous ingredients are
non-hazardous, non-regulated and chemically benign, neutralize it with sodium bicarbonate or baking soda,
and pour them down the lab drains with copious amounts of water.
In addition to the above guidelines, have the students read the “Cleaning Up” section at the end of
each particular experimental procedure in the class textbook, Williamson, Kenneth. Macroscale and
Microscale Organic Experiments, 2nd edition. Lexington, MA: D.C. Heath and Company, 1994 and
follow these instructions.
Before taking the waste downstairs, you can store it temporarily in the hood of room #107, a
general chemistry lab room. Keep a couple of 5 gallon metal solvent cans for common organic solvent
waste (see list of common organic solvent list in previous section B, Waste Organic Solvents). Place a
separate paper label with the name of the solvent or solvents for each and every solvent poured into the
drum. This drum should be labeled overall as the acidic organic solvent waste drum and should not be
poured into the 55 gallon waste drum downstairs, since most organic experiments will involve some use of
mineral acids and will no doubt contaminate this organic solvent waste can. If the solvents are overly
acidic, pour them into the large 2 liter separatory funnels in the back hoods of your lab, add some sodium
bicarbonate aqueous solution, shake it out carefully, pour organic solvent back into the can and discard the
water. By the time you fill the can, you should have at least a dozen labels on it. If this is not taken care of
by community effort among the TA‟s, THE LAB MANAGER WILL ASSIGN THIS TASK TO ONE
PARTICULAR T.A. PER SEMESTER.
Reactive solvents, like acetic anhydride or bromine, for example, should go into separate smaller
containers, as should halogenated solvents, like methylene chloride or chloroform.
Solid organic compounds which are compatible (i.e., most organic solids used in undergraduate
organic labs) can go into one communal wide-mouth glass or plastic jar, naturally, with named labels
attached. Any overly reactive solid, like lithium aluminum hydride or sodium metal, etc., should go into
separate containers. Use your judgment or ask for advice. Acidic or basic aqueous layers with trace
amounts of non-toxic inorganic salt components can be neutralized with sodium bicarbonate or dilute
mineral acids and dispensed into the lab sink drain, as per instructions in the above CRC procedure.
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