Donate surplus chemicals to colleagues or through departmental listserve

Problem: Unused chemicals are being labeled as waste when labs are done using them.
Solution: If you know of a nearby lab that uses that chemical, offer it to them free of charge. If not, departmental listserves are another easy way to offer up unused chemicals. Moreover the same people that pick up your waste will pick up chemicals to be re-distributed. Alternatively, you could donate your unused chemicals to the Chemical Exchange Program.
Cost: Unlike waste, unused chemicals cannot be mixed with other similar chemicals. Also the integrity of the chemicals needs to be uncompromised. There is no monetary incentive for donating unused chemicals.
Benefits: Donating chemicals is a good way for labs to network and increase communication between groups. This can enable future exchanges in equipment, chemicals, or even research techniques. Savings for recipients are immediate.