You're loading Division 1.2 explosives and need to install the floor liner required for this material. What must that liner be made of?

49 CFR 177.835(f); AAMVA CDL Manual Sec. 9.4.1

Explosives are sensitive to friction, impact, and static discharge. A floor liner made of the wrong material can create exactly the spark or friction event the rule is designed to prevent. Getting this detail right before you ever turn the ignition is part of what keeps a load of explosives from becoming an incident.