3.1 Maintain a Current Inventory

The first step to effectively minimizing the amount of hazardous waste generated is to maintain a current inventory of all chemicals being used and stored in labs and work areas. Check chemical inventories first before ordering any new chemicals. It may also be possible to borrow small amounts of chemicals from other labs. Please take the time to check with your colleagues.  

3.2 Use Recycled Chemicals

At this time there is no program available for surplus chemicals. As a good waste management practice, chemicals should not be discarded without first making an effort to find a potential user of the product. 

3.3 Purchasing Chemicals

When ordering new chemicals, only order the amount of chemicals needed for the experiment being conducted. Do not order a larger size container for an experiment that will only last a semester or for an experiment that may occur in the future. Although chemicals usually cost less per unit when purchased in larger containers, when the actual usage, storage, and disposal are factored in, the cost savings diminishes significantly and may result in higher costs overall.

In addition, chemicals in large containers that are not used frequently can be rendered useless over time by contamination or degradation. In general, only order the minimum quantity of a chemical needed for the experiment, or one year’s worth of stock at the absolute most.  

3.4 Nonhazardous Substitutes

There are many nonhazardous substitutes for hazardous chemicals used in laboratories. Hazardous chemicals should be substituted with nonhazardous alternatives whenever possible, in particular those chemicals that are highly toxic, reactive, contain heavy metals, and are known or suspected carcinogens, mutagens, or teratogens.

Examples of nonhazardous chemical substitutes can be found in reference materials such as Prudent Practices in the Laboratory.

3.5 Appropriate Storage Practices

Storing chemicals properly promotes safer and healthier working conditions and extends the usefulness of chemicals. Improperly stored chemicals can result in: 

• Degraded containers that allow chemicals to become contaminated.
• Degraded containers that can release hazardous vapors that are detrimental to the health of lab workers.
• Degraded containers that can release vapors that can affect the integrity of nearby containers.
• Degraded labels that can result in the generation of unknowns.
• Chemicals becoming unstable and/or potentially explosive.
• Purchasing a chemical that is already in the lab or work area. 

More information on chemical storage classes and chemical storage guidelines can be found in the Laboratory Safety Manual and Chemical Hygiene Plan.

3.6 Cylinders and Lecture Bottles

Disposal of cylinders and lecture bottles is expensive, especially if the contents are unknown. Make sure that all cylinders and lecture bottles are labeled and included in chemical inventories. Before placing an order for a cylinder or lecture bottle, determine if the manufacturer will take back the cylinder or lecture bottle when it becomes empty. If at all possible, only order from manufacturers who will accept cylinders and lecture bottles for return. Airgas Incorporated is an eShop supplier of compressed gases for Cornell University. 

3.7 Microscale Activities

If possible, consider switching to microscale experiments. Benefits might include: 

• Reduced costs in chemical purchases and hazardous waste disposal.
• Shorter analysis times.
• Possibly less glassware breakage.
• Less hazardous chemical exposure to employees and students. 
• Minimized potential for fires and explosions. 
• Less space required for chemical and hazardous waste storage.

For more information and training on microscale activities, check out the webpage for the National Microscale Chemistry Center located at Merrimack College.

3.8 Disposal of Nonhazardous Laboratory Waste Chemicals

Some chemicals can be safely and legally disposed of via the regular trash or down the drain to the sanitary sewer.

For more information on disposing of nonhazardous laboratory waste chemicals in the regular trash, see Appendix A. Outlying facilities, please contact your Department Safety Representative for local procedures or contact EHS at askEHS@cornell.edu for consultation.

For more information on disposing of nonhazardous laboratory waste chemicals down the sanitary sewer, see Appendix B. Outlying facilities, please contact your Department Safety Representative for local procedures or contact EHS at askEHS@cornell.edu for consultation.