Thai health officials have dismissed a viral claim that some drinks can become toxic when kept in insulated tumblers, saying standard temperature-control cups do not turn your morning coffee, milk or juice into a health hazard.
The warning, widely shared on social media, claimed that five types of drinks should not be placed in insulated cups because doing so was “like pouring poison into your mouth”.
The Anti-Fake News Centre said the claim referred to milk, herbal drinks, sour or acidic beverages, and salty drinks stored in insulated cups.
Officials said the information was misleading. The issue is not that ordinary insulated cups make drinks poisonous, but that poor storage and cleaning can create hygiene risks.
The Health Literacy and Communication Promotion Division said some drinks may deteriorate if left too long, while microorganisms can grow when cups are not properly cleaned.
People are advised not to leave drinks, especially milk and fruit juice, in insulated tumblers for long periods or overnight. Yesterday’s latte, sadly, does not improve with age. Users should wash cups soon after use, paying close attention to lids, grooves and silicone seals, where stains and mould can collect.
Officials also recommended replacing cups if the inside is badly scratched or if the tumbler develops a strong metallic smell.
