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

HEAVY-METAL WASTE
Protective Equipment.
Safety goggles, gloves and a lab coat should be worn at all times when working with heavy metal-containing
compounds. Volatile compounds, such as mercury-containing chemicals, should be used only in the fume
hood.
Heavy Metal Safety Rules
In protein crystallography we use many heavy metal compounds. Toxicity information is available for just
a few of them. Therefore, assume that all of them are insidious toxins and treat them with great respect.
These rules are very similar to radioisotope rules. You must be introduced to these chemicals; you may not
spontaneously start using them.
1. Research is done by humans. The skill of humans depends on emotional state. Please think about how
coherent you are feeling before doing heavy atom work. Don't rush through a heavy metal experiment
to get somewhere else. Completely focus your attention on the heavy metal experiment.
2. All the heavy atom compounds must be handled with gloves. Wear gloves even to look at the bottles. If
you must touch doorknobs while handling heavy metals, take off the gloves, or get somebody to open
the doors for you. You should also wear a lab coat and closed-toe shoes.
3. Glassware and spatulas used for heavy metal experiments are contaminated forever: Do not return them
to general circulation. Use our dedicated heavy metal spatulas for heavy metals. Clean heavy metal
spatulas with a wet kimwipe. The contaminated kimwipe goes to dry waste (see item 7). Please do
heavy atom experiments in well labelled crystallization trays, whenever possible. If you must use
glassware, clearly label it, and keep it completely separate from non-heavy metal glassware.
4.Weigh heavy metal compounds on weighing paper, or into centrifuge tubes on top of weighing paper.
Use the analytical balances (the ones with enclosures), not the top-loaders. Many of these compounds
are corrosive to the balances, in addition to poisoning all subsequent experiments and experimentalists.
If you spill any, clean up immediately. A spray decontaminant, and a roll of hazardous spill towel are in
room 219A. All clean-up materials go to heavy metal dry waste (see item 7).
5. Use only minimal amounts of heavy atom compounds. Try to keep heavy metal experiments below
1ml, using at most a few milligrams of heavy metal compound. The volume of toxic solution and
disposal bulk may be minimized by soaking the crystals on the tops of Micro Bridges.
6. Special handling: Moderately volatile mercury compounds such as methyl mercuric chloride are stored
in a sealed box. Open that box in the hood and handle these compounds in the hood as much as
possible. We have separate documentation for dimethyl-mercury and tetraethyllead:
http://www.doe-mbi.ucla.edu/People/Recipes/DMM.html
Osmium tetroxide is also volatile, and should be stored in the same kind of vials as dimethylmercury.
Uranium and thorium compounds are radioactive, not just toxic. Document their use on the inventory
sheet stored with the compounds, just as you would any other isotope.
7. Disposal of and planning for disposal of heavy metal wastes: Segregate heavy metals to ease disposal:
Keep mercury compounds in one crystallization tray, platinum reagents in another. Keep track of how
much heavy metal reagent is in each tray. At disposal time, fill in the blanks on a “Hardous Waste ID
Tag”.
Wet and dry trays: Collect liquid heavy metal wastes into screw-cap bottles to take to hazardous waste
disposal. There should be one metal type per bottle (all Hg or all Pt, etc.). Fill in the blanks, and attach
a ``Hazardous Waste ID Tag" to each bottle. After flushing the trays with at least 1 M HNO3, or if the
trays have already dried out at the time of disposal, the contaminated trays qualify as “dry waste” (see
below), so put them into a clear plastic bag (Put the bag inside a box, if there are a lot of trays).
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