What is an emergency (uncontrolled) release of a hazardous substance?

A hazardous substance release requires emergency response if:

• Employees must be evacuated from the area.
• The response comes from outside the immediate release area.
• The release can cause conditions that are immediately dangerous to life and health.
• The release poses a serious threat of fire or explosion.
• The release requires immediate attention because of imminent danger.
• The release may cause high levels of exposure to toxic substances.
• There is uncertainty that the personnel in the work area can handle the severity of the hazard with the available personal protective equipment.
• The situation is unclear or data is lacking on important factors.