The compound is colorless, odorless, slightly basic, salty substance.

It's used as a source of carbon dioxide for leavening in baking, extinguishing fire in dry chemical fire extinguishers, acting as a reagent, and a strong buffering agent in medications.

It's used as an additive in winemaking and as a base in foods and to regulate pH. It is a common ingredient in club soda, where it is used to soften the effect of effervescence.

Is also used as a fire suppression agent ("BC dry chemical") in some dry chemical fire extinguishers, as the principal component of the Purple-K dry chemical, and in some applications of condensed aerosol fire suppression. It is the only dry chemical fire suppression agent recognized by the National Fire Protection Association for firefighting at airport crash rescue sites. It is about twice as effective in fire suppression as sodium bicarbonate.

Potassium bicarbonate is often found added to bottled water to affect taste.

It's an effective fungicide against powdery mildew and apple scab, allowed for use in organic farming. And also has widespread use in crops, especially for neutralizing acidic soil.

Potassium bicarbonate is a potassium supplement for people who have conditions resulting in abnormally low serum potassium levels, or hypokalemia. In addition to using potassium bicarbonate to treat hypokalemia and its potentially dangerous symptoms, doctors prescribe potassium bicarbonate for its potential preventive effects against several other adverse health conditions.

There is approximately 10,000mg of potassium per 25 gram (1 oz) serving.

According to the US Food and Drug Administration (FDA), potassium bicarbonate is noted as GRAS (generally recognized as safe).

Origin: USA
Notes: Food-grade. Meets specifications of USP, Ph. Eur., BP, E501. Kosher certified
CAS #: 298-14-6
aka: potassium hydrogen carbonate or potassium acid carbonate
Specifications are subject to change without notice.
* FDA Disclaimer

Reference
wikipedia.org
livestrong.com