Portable heaters must have an approved device to shut off gas in case of what event?

Portable heaters are designed with safety as a primary concern, particularly because they are often used in various environments where the risk of hazardous conditions can increase. An approved device to shut off the gas is essential in the event of flame extinguishment or combustion failure. This is crucial because if the flame goes out unexpectedly, unburned gas could continue to flow, creating a significant risk of a fire or explosion. By having a mechanism that detects this event and shuts off the gas supply, the device helps prevent dangerous situations and ensures the safe operation of the heater.

While each of the other options addresses important safety issues, they do not specifically relate to the immediate dangers associated with the absence of a flame during operation. A gas leak can be addressed through other safety devices, low pressure indicates a different set of operational concerns, and high temperature typically would trigger other kinds of safety cutoffs or alerts. Flame extinguishment directly impacts the integrity of the heater’s operation, emphasizing the need for immediate gas shut-off to mitigate risks.