sule 66fact, in July 1966, when Rule 66 was adopted, some 600 tons per day of organic solvents were being discharged into the County's atmosphere, representing one-fifth of the total organic19024 M I N E R A L S P I R I T S 663 Revision 10 2025 Mineral Spirits 663 is a medium-boiling aliphatic solvent consisting primarily of C9-C12 saturated hydrocarbons with