An alkyl lead compound may be stabilized by addition thereto of (1) a plurality of different fused ring aromatic hydrocarbons in amount of from 2 to 30% by weight, said hydrocarbons having boiling points of at least 180 degrees at atmospheric pressure and containing up to 20 carbon atoms in the molecule, and (2) a saturated aliphatic monohydric alcohol containing from 1 to 6 carbon atoms in the molecule, there being present 1 to 25% of said alcohol, the total amount of alcohol plus hydrocarbon being from 3 to 45%. Hydrocarbons specified include methyl naphthalene, dimethyl naphthalene, 1,2,3,4-tetrahydronaphthalene, anthracene, ethyl naphthalene, 1,4-dihydropnaphthalene, 1,4-dihydronaphthalene and fluorene. Specification 670,526 is referred to.