Hazardous Materials Transportation Flashcards

Under 49 CFR Part 174, how must a rail car containing hazardous materials be secured when left standing on a track without a locomotive?

Answer: Hand brakes must be applied and the car must be placarded as required

Hand brakes must be set to prevent movement, and required placards must remain in place on any standing hazmat car.

Which class of hazardous materials includes oxidizers that can intensify a fire but are not themselves necessarily flammable?

Answer: Class 5.1

Division 5.1 covers oxidizing substances, which provide oxygen to support or intensify combustion of other materials even without being flammable themselves.

An FRA inspector finds a placarded tank car with a stenciled test date that is overdue for periodic retest. What action must the railroad take?

Answer: Remove the car from hazardous materials service until it passes the required retest

A tank car with an overdue periodic retest may not be used in hazardous materials service until the required retest is completed and the car re-qualified.

What is the significance of a 'W' in a tank car specification marking such as 'DOT-111A100W1'?

Answer: The car has a welded (rather than bolted) construction

The 'W' in DOT tank car specifications denotes welded construction of the tank shell, as opposed to older riveted designs.

Under the FRA's Positive Train Control (PTC) requirements, how does PTC intersect with hazardous materials safety?

Answer: PTC must be operational on main lines that carry poison- or toxic-by-inhalation (PIH/TIH) materials

FRA's PTC mandate prioritizes implementation on lines carrying poison- or toxic-by-inhalation materials due to the severe public safety risk of a derailment involving these commodities.

A shipper improperly labels a package of infectious substances as 'biological samples — exempt.' What FRA/DOT regulation is violated?

Answer: 49 CFR 173.134 — proper classification and description of Division 6.2 materials

Division 6.2 (infectious substances) must be properly classified and described; misclassifying them as exempt violates 49 CFR 173.134 which governs infectious substance exceptions and requirements.

Which action is required before a railroad may transfer hazardous materials between tank cars during an emergency response situation under 49 CFR?

Answer: The operation may proceed only after notifying the NRC and following applicable special permit or emergency response procedures

Emergency transfers must be performed in accordance with applicable special permits or emergency response procedures, and the NRC must be notified if a reportable release has occurred.