Police, specialist firefighters and paramedics are all currently at the scene in Jackson's Lane, Thornhill.
It follows the sudden death of a 76-year-old man, who has not yet been named.
A West Yorkshire Police spokesman said: "Due to chemical materials found in the house, specialist firefighters have attended alongside the ambulance service and the police.
"There is not believed to be any wider threat to the general public and enquiries are ongoing to determine the circumstances of the man’s death."