Abstract: At 8:30 a.m. on May 19, 2012, four Employees working for Resolute Forest Products, were isolating the main isolation valve in the recausticizing area. All four were standing by the suction valve of a pump (2-10 ft away from the valve; Pump Number 1) near the white liquor (mixture of sodium hydroxide, sodium sulfide, and water with a pH of 12.5-13.5) when the valve sleeve failed. The inside of the pinch valve ruptured causing white liquor to spray out of the valve. The suction valve was approximately 1-3 ft off the ground. All four Employees were sprayed and covered in white liquor from head to toe. They suffered 2nd and 3rd degree chemical burns to the body including eyes and skin. All four Employees were wearing personal protective equipment to include: a hard hat, safety glasses, uniform, and steel toed boots. All four Employees were hospitalized.