Storing Chemicals

Minimize the injuries or damage caused by reactions of incompatible chemicals by practicing proper storage and handling. Matt Bruns of Pfizer Research recommended in Environmental Ezine that these 7 groups to be used as a guide for safe chemical storage.

1. Water-reactive, pyrophoric, self-reactive – such as lithium aluminum hydride, butyl lithium, potassium cyanide, and sodium azide. Does not include acidic water-reactive chemicals.

  • Store in secure, sealed secondary container in a dry location, e.g., a dry box or desiccator.
  • Isolate from other groups.
  • Separate from aqueous solutions and protect from water.
  • In refrigerator: Double-contain in bins or plastic bags.

2. Flammable chemicals– such as ethanol, methanol, hexane, toluene, and tetrahydrofuran. Includes combustible liquids with a flash point below 140ºF.

  • Store in flammable safety cabinet (a secondary container) or in a lab-safe refrigerator.
  • Groups 5 and 6 may be stored with this group within a flammable storage cabinet.

3. Liquid and solid oxidizers– such as 30 percent hydrogen peroxide, sodium dichromate, potassium permanganate, and sodium periodate.

  • Cannot be stored with Groups 1, 2, 4, 5, or 6.
  • Store by itself in a dedicated metal cabinet or desiccator.
  • May be stored within a secondary container in a lab cabin et or on a lab shelf segregated from Group 7.
  • Store double-contained in refrigerator segregated from other groups.
  • Large quantities of oxidizers (>3 kilograms) must be kept separate from all other chemicals in a dedicated cabinet.

4. Liquid and solid acids/corrosives– such as sulfuric acid, trifluoroacetic acid, glacial acidic acid, and nitric acid.

  • Store within secondary containment in a cabinet dedicated to acid storage (not with bases). Use secondary storage as spill control.
  • Use additional secondary containment for oxidizing acids and hydrofluoric acids.
  • Separate mineral acids from organic acids.
  • Not all acids are in Group 4 (e.g., benzoic acid is in Group 7). Aqueous solutions of 2 mol/l (moles/liters) concentration and less are exempted and may be stored with Group 7 on lab shelves.

5. Liquid and solid bases/corrosives– such as ammonium hydroxide, sodium hydroxide (includes pellets), and potassium hydroxide.

  • Store within secondary containment in a cabinet dedicated to bases (never with acids). Use secondary containment as spill control.
  • May be stored in a flammable storage cabinet with Group 2 and/or Group 6. Keep separate using secondary containment.
  • Group does not include carbonates, triphosphates, or fluorides. Weak bases are not corrosive, e.g., potassium carbonate is Group 7.
  • Aqueous solutions of 2M concentration and less are exempted and may be stored with Group 7.

6. Nonflammable solvents and other regulated chemicals– such as chloroform, methylene chloride, N-methylpyrollidinone, and dimethylformamide.

  • Group contains nonflammable liquids and Class III combustible organics having a flash point at or above 140ºF, and other regulated chemicals, including carcinogens, mutagens, and teratogens.
  • Store in sealed, secure, secondary containers.
  • Store in cabinets. If stored on shelves and in cabinets, secondary containment is required to contain spills.
  • May be stored within a flammable liquid storage cabinet with Group 2 and Group 5.

7. Low-hazard solids and liquids– such as calcium chloride, copper sulfate, MgSO4, potassium carbonate, boric acid, and PF compounds and intermediates.

  • Group also includes dilute aqueous acids and bases (less than or equal to 2M) and other aqueous solutions.
  • Store in cabinets or on open shelves. Use secondary containment to control spills.
  • Segregate PF compounds and intermediates. Store in boxes or bins.
  • Store dry solids above liquids

Tips for Safe Chemical Storage
Accidents from poor storage techniques of chemicals are 100% preventable. So why do they still happen? According to Environmental Ezine, many times it’s because workers in areas with many chemicals are tempted to store chemicals alphabetically by common name to make them easy to find, but this is a very dangerous practice.

They offered these additional tips for safe chemical storage:

  • Always store minimum quantities, as specified by OSHA. Purchase chemicals in smallest quantities needed
  • Inventory chemicals at least once a year
  • Do not store chemicals on bench tops
  • Keep MSDSs on file and available