I emailed Shell and got a copy of the MSDS. Here's what it lists:
COMPOSITION/INFORMATION ON INGREDIENTS
Chemical Name, CAS No., Concentration
Distillate (petroleum), light hydrocracked, 64741-77-1, 45.00 - 55.00 %
Distillates (petroleum), sweetened middle, 64741-86-2, 15.00 - 25.00 %
Tallow alkyl amine, 61791-44-4, 1.00 - 5.00 %
Naphthalene, 91-20-3, < 1.00 %