The driver, operator or attendant of any tank vehicle shall not leave the vehicle while it is being filled or discharged. Smoking by truck drivers, helpers or attendants shall not be permitted while driving such vehicles, while filling or discharging any tank or compartment or while making any repairs to such vehicles. Motors of tank trucks shall be shut down during making and breaking of hose connections. If loading or unloading is done without the use of a power pump on the truck, the truck motor shall be shut down throughout such operations. No tank or compartment shall be loaded to a volume in excess of 99 and one- fourth percent of its capacity.
(Prior code § 129.1-103)