[1][2][3] They are used against various insects (aphids, mites, beetle larvae, leaf miners, thrips, leafhopper, whitefly, scale) on fruit, vegetable and other crops, as well as against powdery mildew.
[2] Mineral oils were long believed to act by blocking the spiracles of the insect and thus causing suffocation.
[1] IRAC categorises mineral oil in group UNM (non-specific mechanical and physical disruptors).
[1][2][3] This removes or hydrogenates the unsaturated (alkene and aromatic) molecules, which cause plant damage (phytotoxicity), and delivers the C20-C25 fractions, which are the most effective insecticides.
[3] The grades of oil are given by the amount of unsaturated components (unsulfonated residues UR), by the distillation temperature (°C), by the viscosity (SUS), and by the carbon number (nCy).
The US EPA classified aliphatic solvents as Toxicity Category IV (lowest toxicity—regarded as practically non-toxic).