Organic foods are made according to certain production standards. For the vast majority of human history, agriculture can be described as organic; only during the 20th century was a large supply of new synthetic chemicals introduced to the food supply. This more recent style of production is referred to as "conventional." Under organic production, the use of conventional non-organic pesticides, insecticides and herbicides is greatly restricted and saved as a last resort.
If livestock are involved, they must be reared without the routine use of antibiotics and without the use of growth hormones, and generally fed a healthy diet. In most countries, organic produce may not be genetically modified. The application of nanotechnology to food and agriculture is a further technology that needs to be excluded from certified organic food.