Narrow-range oils fall in the superior oil classification. The terms may be used nearly interchangeably. An oil designed to be mixed with water and applied to plants as a spray for pest control. As with dormant oil, the term now refers to the time an application is made rather than to the properties of the oil. A term used to categorize highly refined oils that distill at slightly higher temperatures and over a wider range than the narrow-range oils.
Most supreme oils meet the characteristics of a superior oil.
A term originated by P.J. Chapman in 1947 to categorize summer-use oils that met certain specifications. This included a high proportion of paraffinic hydrocarbons and purification that allowed year-round use without phytotoxicity. Since then, further developments have resulted in oils that distill over a narrow temperature range. Most superior oils are now better referred to as narrow-range oils. Go to top of this page.