An overpack label, as defined in the IATA Dangerous Goods Regulations is an enclosure used by a single shipper to contain one or more packages and to form one handling unit for convenience of handling and stowage.
If you see a label with a skull inside it, in fact, if you see anything with a skull inside it you immediately know something is not quite right. By
GHS Irritant 20mm labels are a small label that go on the outside of whatever a person is despatching to highlight a warning to whomever is handling it. I mean,
Environmentally hazardous labels (marine pollutant label) lets whoever is shipping, transporting and receiving the goods know that they are dangerous to the environment.