As Taiwan prepares to celebrate the Dragon Boat Festival, its local health departments are on the alert for festive treats that fail to meet food safety standards.

The early-summer Dragon Boat Festival will be here next week, and that means one thing- zongzi, or balls of glutinous rice wrapped in leaves with other ingredients and steamed. Vendors across Taiwan are gearing up to meet demand for these seasonal goodies.

But consumers should choose their zongzi carefully-- testing by the Taichung health department has found that frozen zongzi on sale at a local supermarket contained a concentration of E. coli 110 times above the limit set by food safety standards. Fortunately, this product was the only one among the 61 supermarket zongzi the department tested to fail inspection. It was quickly removed from shelves.

Germs aren’t the only risk. In neighboring Changhua County, the local health department forced the recall of some powdered peanut, a topping often eaten with zongzi. That’s after inspectors found that the product contained eight times the acceptable amount of aflatoxin, a carcinogen produced by some kinds of mold.

Fortunately, Taiwan’s health departments are being vigilant, but consumers should stick to trusted makers of zongzi—or, as many do, simply make their own.