How did safety at work become important?

The Industrial Revolution gave rise to Unions which in turn, helped to improve the standards of workers. Manual labor conditions were often dangerous, with grueling long hours, and meager pay. Due to commonplace danger, a worker who was injured was usually fired because they could not work and replaced with no compensation or medical aid or payment. Individual laborers couldn't ask for improvements because they would be fired and another worker would easily replace them simply for a paying job. When all workers asked for better conditions, employers/owners would not be able to replace everyone on their payroll and they would lose money due to lack of production. Compromises were made, and conditions improved over time so that higher-ups could continue to earn money while workers had longer, more productive careers due to their better working conditions. Without safety at the workplace, the best result from the production would not be achieved. Delays and extra payments may have to be made due to accidents or mishaps in the workplace caused by low safety awareness.