Elemental thallium (CAS 7440-28-0) is a bluish-white, very soft metal. Metallic thallium oxidises in air to form a superficial layer of thallous oxide (Tl2O). Thallium forms alloys with other metals and readily amalgamates with mercury.
Examples of work activities involving thallium and its compounds that require special attention when assessing exposure include:
- laboratory analysis where thallium malonate-formate (Clerici’s reagent) is used for mineralogic analysis of rocks, ores and sand, and separation of diamonds
- production of pigments, luminous paints, artificial gems, coloured glass, and special optical glasses for lenses and prisms, electronic devices and switches
- smelters, power plants, cement factories, with a risk of exposure from cleaning fossil fuel furnaces or flues and metal machining.
- manufacture of special alloy anode plates for use in magnesium sea water batteries, and
- manufacture of fireworks (green colour).
This guide provides information for those registered medical practitioners engaged by a PCBU to carry out or supervise health monitoring for workers. This guidance should be read in conjunction with the following: