Which of the following is NOT an acceptable mounting location for propane containers?

The correct response identifies an unsafe practice regarding the placement of propane containers. When it comes to the safety and effective use of propane containers, specific mounting locations are prescribed by regulations and guidelines to minimize risk, particularly associated with impacts and proximity to heat sources.

Mounting propane containers on the exterior of the rear wall is generally deemed unacceptable due to exposure to potential damage from rear-end collisions, which can lead to devastating leaks or explosions. Additionally, this location may not provide adequate protection from environmental factors or prevent thermal issues that could arise from engine heat or road debris.

The other choices highlight safer alternatives. Mounting on the tongue of a trailer, for example, is common and allows for easy access while safeguarding the containers from potential damage. Similarly, placing them in vapor-resistant recesses can help contain any leaks more effectively. Mounting them on the chassis of a motorhome ensures that the containers are supported and secured, mitigating the risk of accidents associated with loose or improperly mounted containers.

Understanding these distinctions is crucial for ensuring the safe handling and installation of propane containers in various vehicles and settings.