Once a chemical incident has been recognized, minimizing the further spread of environmental contamination and preventing further exposure of people and animals is critical. Rapid and efficient steps taken to minimize the spread of contamination can prevent thousands of potentially lethal exposures and devastating environmental effects. Depending on the scenario, the response actions may involve a combination of sheltering, infrastructure shutdown, evacuation, decontamination, remediation, scene control, epidemiological investigation, and/or public information and warning communications. Making full use of the chemical hazard information provided by RPs under EPCRA is critical for minimizing risks when responding to an emergency.
After its initial release and deposition, a chemical may continue to spread throughout the environment by:
- Physical transfer via the movement of vehicles, materials, people, and animals
- Reaerosolization, when a second or subsequent creation of an aerosol occurs creating a fine mist or when many small droplets are raised aloft in the air creating an inhalation hazard, if initially aerosolized
- Resuspension, if deposited out of a water column
- Volatilization, including the vaporization or off-gassing of liquids on clothing, skin, or other materials, or off-gassing of ingested materials through breathing or vomitus
- Continued airborne or waterborne movement
A released chemical may spread via:
![A released chemical may spread viaL movement of vehices, goods, and materials; movement of people and animals; reaerosolization, volatilization, or continued airborne movement; or resuspension or continued waterborne movement.](/sites/default/files/photos/kpf%204%20%2C%201%20-%20A%20released%20chemical%20may%20spread%20via.png)
The released chemical may react with water or other compounds present in the environment to produce potentially more hazardous compounds than the chemical initially released. Thus, chemical spread will increase the environmental impact of the release as well as the number of people who come into contact with the substance and experience subsequent health effects. Critical infrastructure may become contaminated, hampering response operations and reducing the availability of key lifeline services to the region, with the potential for longer-term consequences. Minimizing the spread of contamination will reduce these infrastructure impacts as well as remediation time and cost. In fact, the single most effective means of reducing the level and complexity of wide-area response and recovery activities needed is to limit the extent of contamination within and throughout the area.
Amid activities aimed at preserving unaffected areas and preventing unexposed individuals from being exposed, it is critical that responders are aware of and appropriately manage lingering threats such as the potential for a second release (such as from a damaged rail car), persistent spread of the substance throughout an area, or large quantities of contaminated food. Moreover, when the incident poses a risk to the public, crisis and risk communication strategies should be implemented quickly to ensure the public receives appropriate and timely information and guidance and remains calm (refer to KPF 3, Communicate with External Partners and the Public). Clear communications with the public are key to success in limiting human exposures. The public must be alerted as to what areas to avoid and how to obtain help with decontamination if they are in a contaminated area.
The goals of the response and recovery activities discussed in this Key Planning Factor include:
- Stopping the spread of contamination
- Protecting responder, environmental, and public health through decontamination and other measures
Minimizing the spread of contamination can prevent lethal exposures and devastating environmental effects.