TAIPEI, Taiwan - The Oolong tea variety sold at the National Palace Museum (NPM) has been found to contain two toxic pesticides by toxicity tests, according to the results of tests done on teas sold in the NPM that were revealed yesterday by the Taipei City health department.

Health inspectors found 0.12 ppm of Flufenoxuron and 0.16 ppm of Ethion in a randomly selected sample of oolong tea with an expiration date of Sept. 15, 2011 distributed by iTea.

Flufenoxuron is a carcinogen, and prolonged exposure to Ethion may cause neural damages. Regulations do not allow for any trace of either toxin to be present in tea products.

Quickly responding to the findings, the museum has dissolved its contract with iTea and will return all of its iTea products in inventory at NPM, Feng Ming-chu, deputy director of NPM announced.

On behalf of the museum, Feng apologized for the disturbance it had caused and vowed to tighten quality control on products that it sells.

Consumers who purchased the product can contact the NPM for returns, said Chiang Yu-mei, a Taipei health official.

Two other teas - Four Seasons Spring and Alishan Jinxuan Oolong were tested. Both passed the inspections.

Since the tea is produced in Nantou County, health authorities are collaborating across county jurisdictions. They will fine the manufacturer between NT$60,000 (S$2586) and NT$300,000 for violation of food safety regulations and will order all such products to be destroyed.

Most pesticides are water-soluble and have low tolerance to heat. To avoid the intake of residual pesticide, officials suggest that consumers brew tea with water over 80 degrees Celsius and throw away the first brew.