🌡️ Thermometer

Mercury thermometers are prohibited in checked baggage due to hazmat regulations — mercury is classified as a dangerous substance that can cause significant harm if released in the cargo hold. If one is found during checked baggage screening, it will be removed and you may face delays. The simple solution is to switch to a digital thermometer before flying.

The prohibition on mercury thermometers in checked baggage is consistent across the US, UK, EU, Canada, Australia, and most other aviation systems, as it stems from IATA dangerous goods regulations that apply globally. No major region allows mercury thermometers in checked baggage on commercial aircraft.

A digital thermometer is a standard permitted item in carry-on and checked baggage — it will go through the checkpoint the same as any other small electronic device. No special declaration or exemption is needed. It may occasionally appear as a dense object on the X-ray, prompting a quick secondary check, but there's nothing concerning about it from a security standpoint.

A mercury thermometer cannot be packed in any aircraft baggage — not carry-on, not checked — on commercial flights. If you need a thermometer for travel, replace it with a digital model before your trip. If you're bringing it home after discovering one at a destination, check whether your local pharmacy or hazardous waste facility can dispose of it safely before you fly.