Croatian Post has prepared a leaflet with general information on dangerous goods in international air transport. Objects such as crackers, lighters, glue, lithium batteries or pesticides are just some examples of dangerous goods. In order to avoid undesirable consequences or inconvenience, it is very important that to the question by our employees concerning the content of a mail item to be transported by air you give very precise answers. A mail item can be accepted for transport only if your description of content clearly indicates that there are no dangerous goods inside. The leaflet contains examples of description of mail items which cannot be accepted for air transport and examples of description of mail items which can be accepted for air transport.
The complete leaflet can be found at link, and it contains a list of goods which are prohibited for air transport.