A system for storing chemicals according to chemical compatibility is recommended by EH&S. Separation and segregation of incompatible chemicals reduces the risk of accidental mixing in case of container breakage, fire, earthquake, or response to a laboratory emergency. One example of a detailed classification system for the storage of chemicals grouped by compatibility, developed by Stanford University and recommended by the National Research Council (in Prudent Practices in the Laboratory, 2011) is described below.
- Compatible Chemical Storage Group Classification System
- Chemical Compatibility Storage Groups for Selected Chemicals
This system classifies chemicals into 11 Storage Groups. Each group should be separated by secondary containment (e.g., plastic trays) or, ideally, stored in separate storage cabinets or shelves. Storage Groups B (compatible pyrophoric and water-reactive chemicals) and X (incompatible with all other storage groups) are the most important to segregate from other chemicals. If possible, these two groups of chemicals should be stored in separate cabinets or shelves.
Other chemical storage systems may also be used. Whatever system is used, it should be based on the concept of keeping the chemical groups listed below separated by using secondary containment, cabinets, separate shelves or distance:
- Oxidizers, including peroxides
- Corrosives—inorganic bases
- Corrosives—inorganic acids, not including oxidizers or combustibles
- Flammable materials
- Reproductive toxins
- Select carcinogens
- Chemicals with a high degree of acute toxicity.
Each laboratory needs to develop a chemical storage system that works for their individual lab operations. No matter what system is used be sure to follow any storage information on chemical container labels and in the chemical Safety Data Sheets.