  The main objective of this article is to study the dynamic phase transitions
associated with the spatial-temporal oscillations of the BZ reactions, given by
Field, Koros and Noyes, also referred as the Oregonator. Two criteria are
derived to determine 1) existence of either multiple equilibria or
spatiotemporal oscillations, and 2) the types of transitions. These criteria
gives a complete characterization of the dynamic transitions of the BZ systems
from the homogeneous states. The analysis is carried out using a dynamic
transition theory developed recently by the authors, which has been
successfully applied to a number of problems in science.
