Source:
https://scmp.com/article/322161/wash-fruit-warning-after-contamination

'Wash fruit' warning after contamination

People were warned to wash fruit before eating it after Singapore and Malaysia banned imports of longans, durians and lychees from Thailand because they were contaminated with sulphur dioxide. A government spokeswoman said officials would step up checks of the fruit.

Sulphur dioxide can induce allergic reactions, especially in asthma patients, but is not a dangerous substance in itself.