Analysing dynamics of large biological regulatory networks (BRNs) calls for innovative methods to cope with the state space explosion. Static analysis and abstract interpretation techniques seem promising approaches. In this paper, we address the Process Hitting framework, that has been shown of interest to model dynamics of BRNs with discrete values. We propose to take profit from the particular structures of Process Hitting to build efficient static analyses. We introduce a novel and original method to decide the reachability of the state of a component within a BRN modelled in Process Hitting. The decision is achieved by abstract interpretation and static analysis of Process Hittings. The scalability of our approach is illustrated by its application to the analysis of a BRN with 40 components.