How must hazardous materials transported by rail be labeled on the sides of the railcar?

Hazardous materials transported by rail must be labeled on the sides of the railcar in 4-inch letters. This standard is established to ensure clear visibility and communication of the potential risks associated with the materials being transported. The 4-inch letter requirement helps emergency responders and personnel identify the contents of the car quickly and from a safe distance, which is crucial for safety during transport and in the event of an incident.

While other options present larger letter sizes, they do not conform to the regulations set forth regarding the labeling of railcars. If the letters were smaller, they might not be sufficiently visible, and larger letters, such as 6-inch or 8-inch, could lead to impracticalities in labeling space or could potentially obscure other necessary information. Therefore, the 4-inch standard strikes the right balance between visibility and practicality, ensuring that the labeling is effective and compliant with safety standards.