Open flame ignition sources include which of the following?

Open flame ignition sources are those that can produce flames capable of igniting flammable gases or materials. In this context, cigarettes and lighters fit this definition perfectly. They both provide a direct flame that can ignite gas leaks or flammable substances in the environment.

Cigarettes emit an ember and can burn materials, while lighters generate an actual flame when ignited. Both of these sources can be particularly hazardous in environments where gas is present, making them critical to identify and manage safely.

Other options such as fridges and microwaves typically operate on electric power and don’t generate open flames, hence they do not qualify as open flame ignition sources. Wiring and circuit breakers also don't produce an open flame; they are components of electrical systems that can create sparks under fault conditions, but they aren’t open flames themselves. Smoke detectors and alarms are designed for safety, alerting occupants to smoke or fire and do not produce flames, making them irrelevant as ignition sources.