The baguette is so central to French life that its ingredients and production are regulated by law. In 1993, the French government passed the 'Décret Pain' (Bread Decree) to protect traditional baking from industrialization. According to this law, a 'baguette de tradition française' can only be made with four ingredients: wheat flour, water, salt, and yeast. It cannot be frozen at any stage and must not contain any preservatives or additives. This law was a reaction to the rise of mass-produced, chemically-leavened bread. The long, thin shape of the baguette became popular in the early 20th century because it allowed more of the crust to be exposed to the heat, creating the maximum amount of crunchy exterior, and it baked much faster than traditional round loaves.