Alum
From Cargo Handbook - the world's largest cargo transport guidelines website
Description
A white crystalline substance shipped in canvas bags. Used for various purposes, including dyeing, tanning and printing.
Carries a large percentage of water which may be lost through rise in temperature and drop in humidity. May be subject to loss in weight due to loss of moisture. The effect of this is a powder formation on the crystals, with occasionally a complete breakdown of the crystals to a fine powder. There is, however, no fundamental chemical change. Bags are prone to rotting and tearing, with subsequent loss of weight. Should be stowed away from goods susceptible to moisture, and kept clear of textile goods.