http://hl7.org/fhir/StructureDefinition/openEHR-exposureDescription|4.0.1

Text description about exposure to the Substance.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/string