Abstract: At 4:00 p.m. on December 27, 2019, an employee was performing one of his regular work activities, cleaning and scrubbing the concrete enclosure outside of the kitchen in a restaurant. The employee usually cleans the enclosure at least once a week and, in the past, had only used soap, water, and bleach. On the day of the incident, the employee also decided to use Chemcor scale remover, which contains hydrochloric acid, in the cleaning mixture. The employee poured the bleach and scale remover on the concrete and began to scrub. He then sprayed the concrete with hot water from a hose. The combination of bleach and hydrochloric acid created chlorine gas, which the employee inhaled. There were no direct witnesses to the incident. A lack of effective training on the hazards associated with chemicals used and stored in the workplace lead to the employee being unaware of the hazard of mixing the hydrochloric acid and bleach together. The employee was admitted to the hospital on December 27, 2019, where he was treated and released on December 31, 2019.