We encourage integration and minimization techniques in all laboratory activities involving chemicals, including inventory, purchasing, use, accumulation, and solvent recycling.
Manufacturers’ recommended expiration date
If a chemical has passed its expiration date, it must be evaluated to ensure it is not a waste. Use the following guidelines for making this determination. A chemical is not a waste if:
- It is usable for its originally intended purpose, and is still within specifications
- It can be re-certified or tested, and is within specifications
- It is a peroxide-forming compound, such as ether or tetrahydrofuran, and is still in its useful life, as measured from the time the original container is opened and the amount of exposure to air
Minimization Examples
| Activity | Example/Explanation |
|---|---|
| Inventory | |
| Dispose of expired or unused chemicals. | When you leave the University, do not leave unidentified and unnecessary materials behind. |
| Maintain good condition of labels and containers. | Clean up at the end of every day to avoid creating excess wastes. |
| Check inventory before ordering to avoid duplication. | |
| Purchasing | |
| Buy reusable gas cylinders. It costs $1,000 – $2,000 each to dispose of lecture bottles and cylinders. Some vendors will not take them back. | Return cylinders to manufacturers if valves are defective, or for refills. Get specialty fills in larger cylinders that can be returned. |
| Purchase only as much as you need. | Bulk discounts may cost more due to the eventual need for removal. |
| Check catalogs for quantity choices. | Select the container size appropriate for your use. |
| Use | |
| Reduce the scale of the experiment. | Use micro scale glassware. |
| Share unused portions with other researchers. | |
| Return unused chemicals to vendor. | Even if you are not reimbursed, Stanford saves disposal costs. Make sure the container is labeled and in good condition. |
| Use alternate research methods. | Know the hazards of chemicals. Choose less hazardous materials for investigations and plan to use them. |
| Select less hazardous chemicals. | Less hazardous substitutes are available for degreasing, glass washing and preserving biological specimens. Non-mercury containing thermometers are available, which minimize hazardous waste from thermometer breakage. |
| Reuse chemicals before disposal if possible. | |
| Accumulation | |
| Segregate non-halogenated and halogenated solvents. | Treatment procedures have different costs. Segregation allows some solvents to be recycled. |
| Segregate acids from mixtures of acids and metals. | Keep hydrochloric acid separate from sulfuric acid contaminated with copper. |
