O 1205 (OTTO) n-Octadecane, 99% Cas 593-45-3 - used as a solvent, a lubricant, transformer oil and an anti-corrosion agent. O 1205 (OTTO) n-Octadecane, 99% Cas 593-45-3 - used in paraffin and as a chemical intermediate in organic synthesis. It plays an important role in pheromones as a chemical messenger.