Guidelines for Disposal of Chemical Wastes
Reissued 1 February 1995, Revised14 April 1997

The following set of guidelines was formulated as a result of a meeting between Mr. Jim Fox of EHS and the organic division. They are not immutable, but should be followed as strictly as possible at all times by all research workers.

The disposal of sharps (needles, razors, scalpels, etc.) and incineratable biohazards is governed by a separate set of guidelines .

1. Aqueous solutions that consist mainly of mineral acids/bases that are not highly toxic. These may be poured down the sink after dilution with water or neutralization. These include such acids/bases as sulfuric, hydrochloric, hydrobromic, hydroiodic, nitric, and acetic acids; sodium and potassium hydroxide, sodium and potassium carbonate and bicarbonate.

2. Acids and bases containing heavy metals. These are usually toxic or dangerous oxidants and should not be disposed of down the sink, but should be bottled separately from other wastes and labeled appropriately. These include perchloric, periodic, perbromic, arsenous, stannous, chromic, and similar acids. If in doubt, do not put down the sink, but bottle separately and ask.

3. Non-toxic salts may be diluted and washed down the drain. This includes such materials as the sodium and potassium halides, magnesium and sodium sulfate, calcium carbonate.

4. Toxic metal salts should not be put down the sink. These should be bottled separately from other wastes. These include salts of mercury, thallium, barium oxide, and transition metals of any sort such as chromium trioxide and other chromium salts, selenium, etc.

5. Nonhalogenated waste. All organic materials that re liquid, that do not contain halogens or sulfur, will dissolve in organic solution, and do not contain water may be combined in a common waste container (the "NONHALOGENATED WASTE" container). This includes such common substances as THF, alcohols, acetone, ether, hexanes, DMF, benzene, toluene, used pump oil, etc. There does not have to be a separate container for carcinogenic waste or washings, but it may be appropriate to bottle these separately and label them ( e.g. , benzidine, nitrosomethylurea) for safety in handling by EHS personnel. When in doubt, ask.

6. Halogenated waste. All sulfur and halogen containing organic materials should be combined in a common waste container (the "HALOGENATED WASTE" container). These include tetrahydrothiophene, dichloromethane, chloroform and chloroform- d, carbon tetrachloride, chlorobenzene, dimethyl sulfide, thiophene, thiols, etc. These should not be mixed under any circumstances with the NONHALOGENATED WASTE!! It is thus most reasonable to rinse flasks containing halogenated waste with a SMALL amount of dichloromethane into the halogenated waste. Try to save and recycle excess used dichloromethane in a bottle for this purpose. Be sure to label any such bottles clearly ! In addition, to minimize stench problem, please bottle organosulfur containing wastes in a completely separate container.

7. Corrosive/Reactive waste. Do not simply pour corrosive and/or reactive molecules into any waste bottle. Neutralize carefully to a less nasty form wherever reasonably possible. Example: all acyl chloride waste should be cautiously neutralized with a small amount of waste recycled methanol (result - an ester!) and placed in the HALOGENATED WASTE bottle.

8. Potentially explosive mixtures. Large amounts of potentially explosive or highly reactive material require special measures -- contact your advisor or EHS. Small amounts should be properly neutralized with appropriate precautions (blast shield, face shield). These include lithium aluminum hydride, potassium and sodium and calcium hydride -- (neutralize by careful addition to isopropanol, NOT methanol or water): aluminum or tin(IV) chloride (neutralize by careful, very slow addition to ice water): very small amounts of residue on flasks or syringes ONLY due to butyl or methyl lithium (immediately rinse carefully with ethanol or isopropanol): tert -butyl hydroperoxide and related materials (add carefully to 1:1 water:isopropanol containing ferrous sulfate). Remember, do not try to treat more than about 1-2 g of such materials without consulting your advisor, and always work with extra face protection (blast shield, face shield). Large amounts of residue in old alkyl lithium or in alkali metal bottles require special care -- contact your advisor. Always keep separately bottled any waste that could turn nasty upon addition of acid or water. Methyl isocyante, potassium cyanide, sodium sulfide are examples.

9. Mercury spills. They should be powdered with sulfur, carefully scraped up with a dust pan, and bottled separately. Major mercury spills should be reported to EHS as soon as possible. due to the hazards of mercury vapor. Glassware containing mercury residue should be soaked with concentrated nitric acid for several hours, the acid residue bottles separately as acidic mercury-containing waste, then glassware washed with water.

10. Silica gel, alumina, florisil, celite. Such adsorbents may be placed in a plastic bottle and put in the regular trash except under the following circumstances. (a) if it smells of some organic substance, (b) if it is badly discolored with the usual unknown organic crud from a chromatography on something toxic. In case (b), it is often possible to keep separate the "plug" of discolored material for separate placement in a solid waste jar. Try to keep badly organic contaminated solid waste separate from used but non-gross solid waste. Organic contaminated solid waste should have its organic or hazardous components identified with the usual sticker on the "SOLID WASTE JAR". Do not just jumble everything together without labeling it, even for solid waste!! Rule of thumb -- if you would worry about it staying permanently in your wastebasket, then it should be labeled.

All organic waste should be labeled as in 5-6 above, and should list the materials added or rinsed in as the container is filled. Be sure to list what the major component(s) is(are) as you make additions, and approximate composition (50%:50%, 80%:20%, <5%, etc .). DO THIS AS YOU ADD THE WASTE --DO NOT WAIT UNTIL THE BOTTLE IS FULL AND THEN GUESS -- AFFIX ANOTHER LABEL IF YOU HAVE TO BUT BE SURE TO LIST THE COMPONENTS. The large Winchester size bottle are preferred waste containers, but smaller ones may prove useful for occasional production of things that need to be kept separate (e.g., toxics).

11. DO NOT label with structures!! Always use descriptive names and amounts

12. When a bottle is full, put the date on the bottle, viz ., "FULL on 14 April 1997". You then officially have three days to send the bottle to EHS for disposal. Do not let it just sit around!

13. All sharps (needles, cannulae, syringes, razors, other shap metals) must be placed into separate, plastic containers of a sort that can be obtained for free from EHS (contact Dr. Valerie Steinberg). These containers MUST be used. Do NOT dispose of sharps into glass or general rubbish containers!!

14. Follow the UMass guide for disposal of waste and hazardous chemicals, available from EHS.

When in doubt, ask members of the Safety Committee or call EHS for advice. Better to do it right slowly, than to do it over again. ALWAYS BE THINKING ABOUT WHAT YOU WILL DO WITH THE END PRODUCT OF YOUR REACTIONS!!

Please help the environment and the UMass budget situation by following these guidelines, and by thinking to ask before you act.

Chemistry Department Safety Coordinator