There is no way to say what every supervisor's level of commitment to occupational safety is. Different supervisors in different firms will have different levels of commitment to occupational safety.
Of course, it makes both economic and ethical sense to have a high degree of commitment to occupational safety. This is ethical because supervisors are responsible for the health and safety of their workers while they are on the job. It is economically sensible because workplace accidents can be costly to the company. They can cause the firm's insurance premiums to go up and they can cost the company if a worker who is injured must be compensated for that injury.
While we cannot know what the level of commitment is for all supervisors in general, we can say that supervisors should have a high level of commitment to occupational safety.