Food Safety Focus (145th Issue, August 2018) – Food Incident Highlight

Perchlorate in Tea Leaves and Tea Beverages

Earlier reports from overseas about perchlorate level in tea leaves raised concerns because excessive intake of perchlorate over a prolonged period may cause hypothyroidism.  In view of that tea is commonly consumed in Hong Kong, the Centre for Food Safety hascollected over 300 samples of tea products (including dried tea leaves and tea beverages) from the market for testing and to assess the associated health risks.

Perchlorate is a chemical found naturally in the environment.  It is also an environmental contaminant arising from the use of perchlorate-containing fertilisers and from other industrial uses like processing of explosives products.  Due to its ubiquitous nature, its presence in foods is not unexpected. 

The study results showed that although perchlorate were present in the majority of samples at low levels, the perchlorate exposure of the Hong Kong adult population from dried tea leaves and tea beverages was well below the health-based guidance value established by international authorities.  Therefore, adverse health outcome was remote.