Potash (Potassium Hydroxide) Safety
Potash, or potassium hydroxide, is added to water to raise the pH. It is typically packaged in bags of white pellets or flakes.
This is a dangerous chemical that can cause severe burns to skin, eyes, and respiratory system. It is toxic if swallowed.
Your supplier should furnish you with a Safety Data Sheet (SDS) for Potash. Review it thoroughly and follow all recommendations in the SDS as related to storage, handling, and use--including appropriate personal protective equipment and respiratory protection.
Potash generates a lot of heat when added to water, and may create a violent reaction. It must be added slowly to avoid splashing or splattering.
Also note that it is hygroscopic (absorbs water) and will become wet if exposed to moisture in the air. It should be stored in a cool, dry location in a tightly closed container per the SDS.
It is incompatible with organic chemicals, acids, oxidizing agents and some metals. Again, refer to the SDS for proper storage recommendations.
OSHA includes potash on their Chemical Sampling page also.