Source: Robert M. Rioux & Taslima A. Zaman, Pennsylvania State University, University Park, PA

A mineral acid (or inorganic acid) is defined as a water-soluble acid derived from inorganic minerals by chemical reaction as opposed to organic acids (e.g. acetic acid, formic acid). Examples of mineral acids include:

• Boric acid (CAS No.10043-35-3)
• Chromic acid (CAS No.1333-82-0)
• Hydrochloric acid (CAS No.7647-01-0)
• Hydrofluoric acid (CAS No. 7664-39-3)
• Nitric acid (CAS No. 7697-37-2)
• Perchloric acid (CAS No. 7601-90-3)
• Phosphoric acid (CAS No.7664-38-2)
• Sulfuric acid (CAS No.7664-93-9)

Mineral acids are commonly found in research laboratories and their corrosive nature makes them a significant safety risk. Since they are important reagents in the research laboratory and often do not have substitutes, it is important that they are handled properly and with care. Some acids are even shock sensitive and under certain conditions may cause explosions (i.e., salts of perchloric acid).

1. Engineering Controls

1. Mineral acids should be handled in a chemical fume hood with the sash pulled down between the chest and what is being worked with in the hood. The height of the sash should be that which provides optimal safety while allowing one to execute tasks in an unencumbered manner.
2. Concentration of 3 M (M = molar) or less may be handled on a bench top, remembering that they are still corrosive.
3. Use secondary containers when possible.

2. Perso

The use of mineral acids in laboratories entails considerable health and safety risks, but with proper handling, the potential hazards may be mitigated. While a basic guideline is provided here, this document does not apply to the safe handling of hydrofluoric acid and special directions approved by the principal investigator must be followed. Hazards may vary by experiments or laboratories, which should be assessed carefully to reduce chances of laboratory accidents.

1. University of Illinois at Urbana-Champaign Division of Research Safety: Mineral Acids at https://www.drs.illinois.edu/SafetyLibrary/MineralAcids#
2. Central Washington University Laboratory Standard Operating Procedure for: Mineral Acids at https://www.cwu.edu/facility/sites/cts.cwu.edu.facility/files/documents/Mineral%20Acid%20SOP.pdf
3. Eastern Washington University Standard Operating Procedure for Mineral Acids at https://access.ewu.edu/Documents/HRRR/ehs/Procedures/Mineral%20Acids.pdf
4. Resource Conservation and Recovery Act (RCRA) Regulations at https://www.epa.gov/rcra/resource-conservation-and-recovery-act-rcra-regulations#haz
5. Penn State EHS Chemical and Oil Spill/Release Clean-Up and Reporting Requirements at http://legacy.ehs.psu.edu/envprot/SpillReporting.pdf
6. Occupational Health and Safety (OSHA) Hazard Communication (Standard-29 CFR 1910.1200(f)(1)] at https://www.osha.gov/Publications/laboratory/OSHAquickfacts-lab-safety-labeling-chemical-transfer.pdf
7. The University of Iowa EHS Chemical Storage: Nine Compatible Storage Group System at https://ehs.research.uiowa.edu/chemical-storage-nine-compatible-storage-group-system
8. The University of Maine Storage of Chemicals in Laboratories at http://chemistry.umeche.maine.edu/Safety/Storage.html