Official data from the ATC, which was updated following the explosion at the firework factory in northern Portugal on Tuesday, shows that most of the accidents occurred in January.
Figures show that so far this year, 20 work accidents were fatal and 30 resulted in serious injuries.
The ATC has registered over 400 accidents over the past three years.
In February, three people were killed in work-related accidents, which rose to eight in March.
During the course of 2016, the ATC registered 140 fatal accidents relating to the job.
The ATC defines as a work accident that which occurs in the workplace or during work hours, and directly or indirectly results in bodily injury, functional disturbance or illness, resulting in a reduction in the ability to work, or death.
Work accidents are also considered accidents in travel, transport or movement, in which workers are injured and occur because of or during the course of work, that is, when they carry out an activity or perform tasks for the employer.