Waste Minimization / Pollution PreventionThe Waste Management Hierarchy
There are a variety of methods to deal with the challenges of hazardous wastes.
The waste management hierarchy above shows methods of dealing with hazardous waste in order of preference. The most preferable option on the hierarchy is to reduce the amount of waste that is produced in the first place. This approach—known as source reduction—means that no one has to deal with the waste at all. This is the cornerstone of pollution prevention.
Effective waste minimization begins with effective purchasing decisions. The idea is to buy only what you need because if you don't buy it, you don't have to get rid of it.
In many laboratories, unused chemicals have not yet made it into the waste stream. These laboratories have an inventory of unused chemicals left over by former teachers or researchers. They may be useless (or even unstable) because their shelf life has expired. Containers may be in poor condition. They may be poorly labeled or unlabeled. Unused chemicals can present a safety hazard in the lab and are likely to be difficult and expensive to dispose.
All researchers estimate the quantity of a chemical that they will need before purchasing that chemical. Problems arise when these estimates are inaccurate. The simplest way is to estimate the quantity of a chemical that you will need for a single experiment. That estimate is likely to be more accurate than an estimate of how much you will need for an entire year. An important fact to consider, however, is that the cost savings associated with buying in bulk are frequently offset by the costs of disposing of the unused chemicals.
In addition to buying chemicals in smaller amounts, there are other purchasing strategies that can reduce the amount of chemical waste generated, such as:
Waste minimization in the laboratory doesn't necessarily require major changes in the way experiments are performed. Some basic efforts to be more efficient and careful with experimental procedures can substantially reduce the amount of waste generated.
A starting point for waste minimization is being efficient in your use of resources.
Finally, a good way to get students thinking about waste minimization as they run experiments is to have them actually research waste minimization techniques. You might think of including an experiment in your curriculum that actually gets the students to identify ways to minimize use of hazardous chemicals or generation of hazardous byproducts.
Document Initiator: Kirk Matin