Final answer:
A carbon monoxide detector is required in buildings with fossil fuel burning equipment because carbon monoxide is a highly toxic gas that is produced when fossil fuels burn incompletely.
Step-by-step explanation:
The type of detector required in any building that contains fossil fuel burning equipment is a carbon monoxide detector. Carbon monoxide is a highly toxic gas that is produced when fossil fuels burn incompletely. Unlike other household gases such as ammonia or natural gas, carbon monoxide is tasteless and odorless, making it difficult to detect without a specific detector.