3 types of smoke detector ionization: ie radioactive, tiny piece of americanium, allegedly safe. more responsive to fast burning fires photelectric: uses a light sensor and a light beam. more responsive to slow burning fires. and a hybrid, supposed to be the best of both worlds. if you don't trust the ionizing smoke alarms, and i have no idea if you should or not, consider photoelectric. if you're not worried about ionizing smoke alarms consider an upgrade to the newer style hybrid alarms
Canada