Many climbers use chalk or magnesium carbonate (MgCO3) to combat moisture and keep their hands dry to improve grip on the rock and hand holds, as the hands can get sweaty from the temperature or physical exertion. This chalk is also used by gymnasts as well as weight lifters for the same reason. Climbing chalk can come in four different types: Loose chalk, chalk blocks, chalk balls which are essentially loose chalk contained in a porous fabric material and dispenses chalk when squeezed, and less commonly used, liquid chalk. For convenience, you put them in chalk bags.
Use of chalk and chalk bags in Singapore
In Singapore, loose chalk and chalk balls are commonly used for sport or rock climbing, but it is recommended to use chalk balls for hygiene purposes and to practice good climbing etiquette, to minimize spilling loose chalk in gyms. Chalk is usually contained in chalk bags, with a tubular structure, draw string closure and stiff rim to keep the bag open to dip your hands into the chalk, and lined with a fleece-like base to keep the chalk down to reduce chalk dust flying. The chalk bag is worn around the waist with a simple belt and clip closure. Some chalk bags contain a toothbrush loop to keep brushes to clean holds that have accumulated chalk. People who do bouldering (boulder climbing) usually opt for a larger chalk bag to sit on the ground, chalking up between boulder attempts.
One should note that while pure magnesium carbonate is non-toxic if accidentally ingested though when used in excess, may cause skin and lung irritation, but some climbing chalk may contain additives and drying agents so it is advised to exercise caution to wash your hands after and in between climbs to keep your hands clean and your skin happy.