Purchase only what you'll use, especially if you're purchasing a hazardous chemical. One recent study showed that up to 40% of the hazardous waste produced by laboratories is actually unused and expired chemicals. Unwanted chemicals take up valuable room, cost you additional time when you clean and inventory, and pose additional unneeded risk of spills and exposure.
Choose small bottles if you only need a small amount. Avoid buying in bulk unless you know you will use it all within its expiration date.
If you have chemicals in good condition that you do not need, consider listing them in the UW Chemical Exchange.
For more information, see the American Chemical Society's Less is Better guide..