Biohazard

Biological dangers: germs, viruses, infectious material and biological toxins.

You'll see the real sign on hospital sharps bins, medical-waste bags, specimen containers and many laboratory doors, often black on yellow or orange (colour rules vary by country). It was created in 1966 by engineers at the US chemical company Dow Chemical, working under contract for the US National Cancer Institute, part of the National Institutes of Health, who wanted one distinctive mark that was easy to recognise at a glance. Today it is the international sign for biological hazard.

It is not a general poison or chemical warning, and it does not mean radiation. A skull and crossbones marks toxic chemicals; ☢️ covers radioactivity.

What does it mean when someone sends ☣️?

Usually "gross", "toxic" or "contagious", said with a grin.

After a story about mouldy leftovers, a filthy bathroom or a cold going round the office, ☣️ is dark humour: don't touch it, don't come near me. People also use it for a messy situation or a person they call toxic. Next to real news about an outbreak, a lab or hospital waste, read it literally.