In the US, food regulation is split in two. As they put it, the Food and Drug Administration (FDA) regulates most "food or food additives" in the US, including the production, packaging, labeling, and sale of food besides meat and poultry. Meat and poultry are regulated by the US Department of Agriculture (USDA). The USDA regulates the production, slaughter, and sale of all meat and meat products. These agency's joint decision on cell-based meats will treat these new products as different things at different points along the process of turning cells into meat.
The FDA will oversee the growth and production of cells. At harvest time, when the cells are collected to be turned into meat, regulation will transfer to the USDA. The decision can be seen as a win for the companies that make cell based meat, which advocated for a similar set up in a letter to the White House in August.
To learn more about the growing field of cellular agriculture, read Massive's free report on the state of this research.