Everyone in an ashfall zone will be exposed to the effects of volcanic ash. Fine grained volcanic ash can infiltrate all but the most tightly sealed buildings and machinery and is often small enough (less than 10 microns) to be inhaled deeply into the lungs. Ashfall over extensive areas can prevent travel for days because of poor visibility, slippery roads, and damage to vehicles. Power outages may occur before, during, and after an ashfall either due to equipment failure or because power facilities are temporarily shut down to prevent damage. Afterwards, wind and human activity can stir up ash for weeks to years.
In most situations, acting on a few general principles will reduce the effects of ash and make cleanup operations easier. These principles apply to households, businesses, and communities.
General principles:Keep ash out of buildings, machinery, vehicles, downspouts, water supplies, and wastewater systems (for example, storm drains) as much as possible. The most effective method to prevent ash-induced damage to machinery is to shut down, close off or seal equipment until ash is removed from the immediate environment, but this may not be practical in all cases, especially for critical facilities. Minimize exposure to airborne ash by using dust or filter masks (or a wet cloth, for example a handkerchief) and minimizing travel.
Coordinate cleanup activities with neighbors and community-wide operations (learn the cleanup guidelines and instructions of your local community and leaders). After an ashfall, promptly notify building owners to remove ash from roofs in a timely manner to prevent streets from being repetitively cleaned. Stay informed of volcanic activity in your area, especially during a period of unrest, and know what to expect, including the type of eruptions that can occur and how much warning is possible for ashfall in your area once an explosive eruption occurs. Learn about evacuation procedures, if any, in your area. Prepare for an emergency by having critical provisions and supplies needed to support your family, business, or community for at least several days; for example, food, water, medicine, and shelter, dust masks and other personal protection equipment, spare filters and parts for machinery and vehicles. Develop and test a contingency plan that can be used in a variety of emergencies, but not necessarily focused on volcanoes.