Mercuric chloride (mercury II chloride), HgCl2 is a binary salt composed of white crystals or powder. It is odorless and soluble in water. It is highly toxic by ingestion, inhalation, and skin absorption. The TLV is 0.05 mg/m^3 of air. The four-digit UN identification number is 1624. The primary use of mercuric chloride are in embalming fluids, insecticides, fungicides, wood preservatives, photography, textile printing. And dry batteries.