We all know mercury is a silvery metal in liquid form. Probably most of us first saw it in childhood at the mirror like shining bulb end of thermometer when doctor pushed it in to our mouth .
Mercury is highly corrosive to aluminium and is classified as Corrosive Substances (Class 8) in model regulations. Recent study of corrosive effect of Mercury on Aluminium states that heavy and sudden corrosion will take place leading to pitting and cracking which increases by presence of humidity. On mild steel the corrosion rate is.25mm/year.
Mercury is traditionally sold in flasks measuring about 2.5 litres (34.5 kg or 76 lb.). This weight is equal to one Spanish quintals; of course Spain was one of the biggest producers of mercury. Mercury is having high density ( 13.54562 g/cm3)
For sea transport IMDG Code list mercury under UN 2809 MERCURY Class 8 with special instruction prohibiting transport by hovercraft and other ships constructed from aluminium. IMDG Code allows flasks up to 3L for transporting Mercury by sea, including the empty flask the total gross mass per flask may be around 45-50 kg.
Due to the toxic effects of Mercury UN Model regulations is being modified to include a subsidiary risk (Class 6.1) to the entry UN 2809 which will come into effect in new amendment of IMDG Code (36-12) and an additional entry for manufactured articles containing Mercury.
- What can mercury do to the environment (wiki.answers.com)