Chemical Emergencies:

Chemical emergencies occur when there is a release of chemicals into the atmosphere that could have harmful effects on people's health. A release of chemicals into the environment could be intentional, in the case of a terrorist attack, or unintentional, in the case of a train derailment. Since you may not immediately be aware of what type of chemical has been released, it is important to get to a safe place and follow the guidance of local officials. You may be advised by local officials to shelter-in-place or evacuate.