I now also have two of the Heiman Zigbee smoke detectors. And like @gregpn have it working with the Gas driver @cuboy29 pasted in Driver for Gas Sensor.
I also noticed there is now an official Hubitat system driver, "Heiman Zigbee Gas Detector". But it is not usable, as when using that driver the device does not show in Hubitat Safety Monitor at all, even though the driver logs events correctly when pressing the test button. Using cuboy29's driver it does show correctly in Hubitat Safety Monitor as a smoke detector.
@mike.maxwell from the gas detector thread it looks like you worked on this. Could the Smoke Detector be added to the official driver?
The fingerprint for the Heiman HS1SA Smart Smoke Sensor is
ID: C4A1
Manufacturer: HEIMAN
Product Name:
Model Number: SmokeSensor-EM
deviceTypeId: 16
manufacturer : HEIMAN
idAsInt : 1
inClusters : 0000,0001,0003,0500,0502
endpointId : 01
profileId : 0104
application : 12
outClusters : 0019
initialized : true
model : SmokeSensor-EM
stage : 4