New York Codes, Rules and Regulations
Title 21 - Miscellaneous
Chapter XXIV - The Port Authority Of New York And New Jersey
Subchapter A - Vehicular Crossings
Article 2 - Transportation of Hazardous Material
Part 1211 - Regulations Applying To Lincoln Tunnel, Holland Tunnel, George Washington Bridge Lower Level And George Washington Bridge Expressway
Flammable Liquids-Tunnel, G.W.B. Lower Level and G.W.B. Expressway Restrictions
Section 1211.74 - Zirconium

Zirconium, metallic, solutions or mixtures thereof, are restricted to a maximum quantity per vehicle[FN*] of 10 gallons or 100 pounds gross weight provided, however, such liquids are inside metal cans with not more than 20 individual glass or porcelain jars, not exceeding two-ounce capacity each. There are no restrictions on the transport of empty containers which last contained zirconium, metallic, solutions or mixtures thereof provided the accompanying shipping papers show that they are drained of the liquid and securely closed.

[FN*] A tank vehicle used for the transportation of any flammable liquid, regardless of the quantity being transported, or whether loaded or empty, shall not enter either a tunnel, the George Washington Bridge Lower Level or George Washington Bride Expressway; nor shall an empty tank vehicle containing residue of cut-back tar or cement or of any other substance thinned with a flammable liquid enter said facilities. A new tank vehicle, however, which has never been used for the transportation of a flammable liquid is allowed passage provided it is accompanied by an invoice, or other shipping paper, stating that the tank vehicle has never been so used.