Final answer:
The responsibility of establishing an emergency action plan falls on employers as mandated by OSHA, ensuring a workplace free from serious hazards.
Step-by-step explanation:
The establishment of the emergency action plan is primarily the responsibility of employers. The Occupational Safety and Health Administration (OSHA) mandates that employers must provide a safe workplace without serious hazards and adhere to all safety and health standards. It is incumbent upon employers to identify, inform, and correct safety and health problems in the workplace. Employers are urged to use feasible measures to mitigate hazards, such as safer chemicals or improved ventilation systems, instead of relying solely on personal protective equipment.