Your best source for complete information on the NFPA 70E Standard is via the actual standard, available for purchase at www.nfpa.org. In 2000, the NFPA 70E Standard first addressed electric arc flash hazard and required flame resistant arc flash clothing to protect workers. The current edition of the NFPA 70E standard was released in 2012, and further details personal protective equipment.
Fluoride ions exist predominantly as hydrofluoric acid in acidic environments with a pH below 5.2. Fluoride ions corrode the glass. Therefore, the pH measurement with the glass electrode for a solution which includes fluoride ions is basically impossible. Although the useful life of the electrode may be shortened, however, the measurement with immersing the electrode in the sample for a given short time is possible.
Fluoride mouth rinse is a concentrated solution intended for daily or weekly use. The most common fluoride compound used in mouth rinse is sodium fluoride. Over-the-counter solutions of 0.05% sodium fluoride (230 ppm fluoride) for daily rinsing are available for use by persons older than 6 years of age.luoride mouth rinse is a concentrated solution intended for daily or weekly use. The most common fluoride compound used in mouth rinse is sodium fluoride. Over-the-counter solutions of 0.05% sodium fluoride (230 ppm fluoride) for daily rinsing are available for use by persons older than 6 years of age.