The California Department of Food and Agriculture has adopted new olive oil standards that are designed to reduce adulterated or inferior product.
The standards only apply to California producers with volumes of 5,000 gallons or more, according to test of the rule.
About 100 olive growers and a dozen millers fit that criteria.
The proposal was originally brought forward by the Olive Oil Commission of California, which has called for new testing and labeling requirements.
The new rules would eliminate the terms "light," which describes oil that's been treated with chemicals or additives, and "pure," which describes a mixture of virgin and refined olive oils.
Both of these would now have to be labeled as refined oils.
The rule also contains specific definitions of extra virgin and virin olive oils as well as approved sampling and testing protocols.
The regulations are based on scientific studies conducted by the University of California, Davis' Olive Oil Center.
They take effect Sept. 26.