Viscous black substance on skin in setting of history of working with coal<unk>  or asphalt
May be hardened or still relatively fluid on presentation to ED
May be hardened or still relatively fluid on presentation to ED
Tar burn
Caustic ingestion
Nailbed laceration
Caustic eye exposure 
Cement burn
Caustic dermal burn
Frostbite
Airbag-related burns