Don’t panic! Modern gas safety systems are designed to isolate the supply in the event of a power outage. The building services team should be able to confirm this. The smell is probably a common solvent. Even an experienced chemist would struggle to identify most chemicals by smell; a layperson might easily misidentify solvent vapours as a gas leak. During a power cut, ventilation systems aren’t functioning and solvent smell is likely to seep out. Since many safety systems aren’t working either, the building should be evacuated.

Charles Harrison is a safety adviser at a UK university