Little attention is given to the impacts of chemical exposure on construction workers' health and the environment. Out of 302 reported and analyzed cases to the Department of Safety and Health (DOSH) from 2010 to 2019, about 0.66 are exposure to hazardous chemicals. This paper developed an AHP model for the factors and sub-factors of chemical exposure and determined their relative weights and priorities. Worker's unsafe actions have a maximum weight of about 80.98 for the significant factors based on the proposed model, followed by unsafe site conditions of 10.89 and management factors of 8.13. Financial constraint carries the most weight with 20.22 for management factors, lack of or improper on-site storage for hazardous chemicals, incorrect labelled or unlabeled signs indicating hazardous chemicals, incorrect labelled or unlabeled containers carrying hazardous chemicals and lack of or improper on-site disposal of used hazardous chemicals with 16.13 each carry the most weight for unsafe site conditions. Rushing to complete the job and unauthorized access to the hazardous chemicals carry the most weight, with 17.24 each. This study can help safety practitioners understand the factors and sub-factors responsible for chemical exposure and how they can decrease fatal accidents on-site. © 2021 Author(s).