University Safety and Assurances

Corrosive Chemical Storage

 

Corrosive chemicals because of their nature, prevalence in the laboratory, and variety of concentrations, constitute a series of hazards ranging from poisoning, burning and gassing, through explosion. Serious injury can result from exposure to strong acids or caustics in either the liquid, solid, or gaseous states. Corrosive chemicals in a science laboratory are usually strong acids and/or bases. Laboratory employees handling strong corrosives should always wear proper eye- and skin-protective clothing and equipment (Wear acid-proof aprons, gloves and face shields when handling highly corrosive materials such as strong mineral acids or alkyl hydroxides).

Employees should also be informed of the dangers of tissue contact with corrosives. Should there be contact between corrosives and any body tissue, particularly the eyes, immediately flush the area of contact with cool water for fifteen (15) minutes. Remove all affected clothing and immediately seek medical assistance.

Below are some guidelines for proper storage of some common corrosive materials, such as:

 

  • Ammonium Hydroxide -- Ammonium hydroxide is a base, or caustic chemical which should be kept separate from all acids. All acids are generally incompatible with bases. Ammonium Hydroxide does not substantially attack steel, painted steel or wood, so no special cabinet is needed for it.
  • Acetic Acid and Picric Acid -- are organic acids and should be kept separate from the inorganic, or mineral acids, such as Phosphoric Acid, Hydrochloric Acid, Nitric Acid, Sulfuric Acid, and (especially) Perchloric Acid. Acetic Acid is also combustible and more appropriately stored in a flammable storage cabinet.
  • Phosphoric Acid*
  • Hydrochloric Acid*
  • Nitric Acid
  • Sulfuric Acid*
  • Perchloric Acid*

*The mineral acids, Phosphoric Acid, Hydrochloric Acid, Nitric Acid, Sulfuric Acid, and Perchloric Acid can all be stored in a cabinet designed for Corrosive Acids.


 

SciMatCo and Justrite are examples of manufacturers that make non-metallic cabinets for these types of acids. Both brands are available from laboratory supply and safety supply companies. Some of the important design features of corrosive cabinets include:

  • no internal metallic parts
  • acid resistant coating
  • cabinet floor constructed to be able to contain spillage.

You may also want to specify cabinet vents if you intend to connect the cabinet to an external exhaust.

Concentrated mineral acids can be very reactive, even with each other. Concentrated acids can even react vigorously with dilute solutions of the same acid, if mixed together rapidly. For example: concentrated sulfuric acid mixed quickly with 1 molar sulfuric acid will generate a lot of heat. Different acids should be stored apart. If stored within the same cabinet, plastic trays, tubs or buckets work well to keep different acids apart within the cabinet.

Acids can only be used where an emergency eyewash is located within the immediate vicinity. Strict adherence to safety goggle use procedures is necessary when using acids and bases. All occupants of rooms where corrosives are used must be familiar with the Material Safety Data Sheets (MSDSs) for those materials.

Finally, you should attempt to minimize the amount of acid stored to the smallest amount practical:

  • Picric Acid and Perchloric Acid volumes should always be kept at an absolute minimum.
  • Picric Acid can form explosive salts with many metals, or by itself when dry.
  • Perchloric Acid is an extremely powerful oxidizer and must be kept away from all organic materials, including wood.
  • Perchloric Acid, if heated, must be used in a specially designed Perchloric Acid washdown fume hood, that can't be used for anything else.

In summary, you may need one or more acid resistant cabinets, depending on the volume you intend to store. Nonmetallic cabinet(s) are recommended in addition to some other means to further isolate the different acids within the cabinet(s). Ammonium Hydroxide should be stored away from the other acids. Acetic Acid and Picric Acid should be stored in a flammable storage cabinet. The amounts of acid stored should be minimized, especially for Picric Acid and Perchloric Acid. All precautions listed on the MSDS should be understood and followed.

For further information on chemical safety, contact your professor, supervisor, principal investigator or the Department of University Safety and Assurances.