Yes. Look at osha.Org for full listings of prevention for various occupations and substances.
Yes. If you work in an environment with significant risk of occupational exposures, your company should have a safety plan and likely a safety officer. They will be a valuable source of information to help prevent exposures in the workplace.
Usually. Employers have an obligation to protect employees from hazards. There is a stepwise approach to this. First engineering controls are used to remove hazards. If that can't stop all exposure then administrative controls to keep people minimally exposed. If there still is a hazard then personal protective equipment is used.