Abstract: At 4:51 a.m. on January 15, 2022, Employee #1, and Employee #2 (Millwrights) were assigned to replace a pump in a Methylene Diphenyl Diisocyanate (MDI) Unit at the Di-Chlorination Column at approximately 2:00 a.m. The discharge line for this column discharges about a foot off the ground right next to the pump where the employees were working. The employees were working at ground level, had removed the old pump, and were starting to replace it with a PP4800 pump. As they started to install the new pump, a process rupture disc operating above 30 psi three stories up blew. The rupture caused MDI product at a temperature of approximately 400-degree Fahrenheit to discharge into their work area. Employee #1 incurred severe chemical burns to his back and torso which were life threatening. Employee #2 incurred minor chemical burns to his legs, thighs, and hands. Both employees were transported to a local hospital, where they were evaluated and eventually transported to a different hospital where they were admitted.