Today, elastic optical networks (EONs) are required to accommodate traffic with different service priorities. For example, mission‐critical applications such as industrial internet, smart grids, and remote surgery require an ultra‐reliable low‐latency communication system. The novel impairment‐aware resource allocation scheme proposed here prioritises traffic. It satisfies the quality and latency requirements of mission‐critical traffic while causing minimum disruptions to other forms of low‐priority traffic connections. The results obtained for 6‐node and 14‐node networks under various traffic distribution environments indicate that the proposed algorithm achieves higher spectral efficiency, reduces spectrum fragmentation, and causes minimal disruptions over the benchmark algorithm.