Proper storage helps that the lithiumaluminiumhydride remains active for a long time. Often the compound is delivered in a plastic bag and the bag is soldered in a can. If you open the can and then the bag and after removing the needed quantity you simply plug the bag back into the can then do not be astonished if it needs only days to get the lithiumaluminiumhydride decomposed. If it was you who opened can and bag then it is your job to transfer all of the material into a dry and wide necked vial. Empty the bag onto a sheet of weighing paper first and then transfer from the paper into the vial. Immerse bag and paper completely into water to ensure that there are no residues of active material. Then dispose into the household waste. Wipe the used work space with a moist cloth for the same reason.
Dispose lithiumaluminiumhydrid in a separate bottle. Small quantities may also be deactivated. There are several methods of deactivation - all of them with advantages and disadvantages:
Use water if possible!
Since in theses cases organic solvents are still present water is no more suitable, because on the vigorous reaction the mixture may ignite. Deactivate with ethyl acetate or better with alcohol (gas evolution to monitore the reaction). Take care that all of the compound is covered with solvent. Be very careful at the beginning - later on you may speed up the addition of the reagent. Do not be overhasty, but reserve sufficient time instead! The slower the reaction the lower the risk of an accident. If hydrogen gas is developed, draw it of in a pipe into the fume hood's flue.
When the reaction is died down leave the mixture standing alone over night. Next day add water - at the beginning very carefully and again leave the mixture standing alone. Precipitations are dissolved by adding hydrochloric acid.
Spatulas, flasks, filters, bags (where the compound has been delivered.) - all this is completely immersed in water (no air bubbles!) to decompose all adherent residues. Wipe used work areas or balances with a moist cellulose sheet.