Glossary

#10 Can: A metal can, about the size of a paint can, that food with a long shelf life is often stored in. The size is close to that of 1 gallon paint cans (#10 cans can hold about 110oz of water). The cans are usually enameled and hermetically sealed, and have oxygen removed, for the best shelf life. Mountain House sells food in #10 cans. These are pronounced "Number 10", not "10 Pound." They can have a shelf life of over 25 years. See also Pouch.
Air Burst: A nuclear detonation that occurs high enough in the air so that nothing from the ground gets vaporized. With a ground burst, there is initial radiation, but minimal fallout. See also Ground Burst.
Air Lock: A small room in some shelters that has two airtight doors, one leading from the outside into the shelter, and the other leading from the air lock into the rest of the shelter. After entering, the air is purged and fresh filtered air is brought in, with slight overpressure. This helps ensure that radiation, contaminated air, and blast pressure do not enter the main part of the shelter. The air lock may be separate from the shelter, with a tunnel leading to the shelter. See also Decontamination Room.
Bar: A unit of pressure. Most shelters are designed to withstand at least 3.4 bar (50PSI), or about 3.4 times the normal pressure of air at sea level). See also PSI.
Basement Shelter: A shelter that is built into an existing basement. In most cases, these will not adequately protect you from nuclear detonations, as they do not have enough strength to withstand high pressures. Also, care must be taken to make sure that there is enough mass around them to protect from radiation.
Biological: This refers attacks using biological means, such as bacteria (plague, anthrax), viruses (smallpox), toxins (botulism, tetanus). It even includes diseases that attack animals and crops. See also Chemical.
Blast Door: A door to a shelter that is designed to withstand fairly high pressure from a nuclear blast. They are heavy, usually made of steel, and often filled with concrete. Common sizes are 32"x72" (81x183cm) and 36"x80" (91x203cm). They may weigh 2,000lbs or more (900kg).
Blast Hatch: A blast hatch is like a small door, on the top of the NBC shelter, that allows escape if exit through the blast door is not possible. A typical size is 32"x24" (81x61cm). They can be set up to open outward (on or above ground), or to open inward (typically installed underground with sand above, so you have radiation protection above you). A blast hatch does not need to be as strong as a blast door, as there is less pressure against a horizontally mounted door.
Blast Valve: A device located in air pipes that blocks the pipe when high pressure occurs after a nuclear detonation. This prevents the pressure from destroying the ventilation system and harming people inside the shelter.
Bomb Shelter: A small room designed to offer protection from bombs (sometimes conventional bombs, sometimes nuclear). A traditional bomb shelter may not provide protection against chemical or biological attacks. See also NBC Shelter, Fallout Shelter.
Carbon Dioxide: A gas that people generate after breathing in oxygen. If a shelter is sealed, with no ventilation, each occupant needs about 16 cubic feet of air (.45 cubic meters) per hour. If you plan to seal the shelter from outside air for 6 hours, it would require about 100CF (2.8 cubic meters) of air per person. When calculating the maximum number of occupants, you need to factor in the space taken up by people, beds, food, etc.
Carbon Dioxide Scrubber: A device that removes some carbon dioxide from the air, allowing a shelter to stay sealed longer before occupants would be affected by the carbon dioxide in the air.
Chemical: This refers to attacks using man-made chemicals (as opposed to naturally occurring biological agents). This includes mustard gas, nerve gas, and tear gas. See also Biological.
Chemical Toilet: A toilet that uses chemicals to disinfect and deodorize, rather than having the waste go through sewage pipes or to a septic system. In an NBC shelter, this would prevent the need for a septic tank (and/or allow usage of the toilet if the septic system failed).
Concrete: A very strong material that is used for many NBC shelters. Some shelters are made almost entirely of concrete, others use a combination of metal and concrete. Blast doors typically are steel filled with concrete. Every 8 inches (20cm) of concrete blocks about 90% of radiation (every 2.2-2.4 inches, 5.6-6.1cm, blocks 50%) . See also Reinforced Concrete.
Corrugated Steel: A material often used to create NBC shelters. It is metal with ridges, which improves the ability of the shelter to withstand high pressures.
Crank Handle: See Manual Crank.
Decontamination Room: A small room in a shelter (sometimes in the air lock), that is used for undressing and re-dressing in clean clothes, and showering, to remove as much contamination (radioactive material, biological agents, etc.) as possible. See also Air Lock.
Debris Jack: See Gas Spring.
Dehydrated: Food that has had the water removed through heat (such as being in the sun, or through a manufacturing process). See also Freeze Dried.
Electromagnetic Pulse: See EMP.
EMP: Electromagnetic Pulse. A burst of electomagnetic radiation that occurs immediately after a nuclear explosion. Wires and other conductive metals will 'pick up' this radiation, which then generates high voltages. The high voltages can then destroy all types of electronics (computers, telephones, lightbulbs). See also Faraday Cage, HEMP.
Expedient Shelter: A shelter that is made with little advanced warning, with whatever materials you happen to have on hand. It typically will provide some protection against radiation, but not nearly as much as a properly designed shelter (for example, there will normally be little protection against gamma radiation from a roof). Same as Improvised Shelter.
Fallout: The radioactive dust that falls to the ground after a nuclear explosion, starting about 30-60 minutes after the explosion. Without proper protection (usually several feet of concrete or dirt), people in areas of fallout will be exposed to radiation 24 hours a day.
Fallout Shelter: An indoor area, usually under a building (such as a basement) that protects people from the effects of radiation after a nuclear blast. It does not provide blast protection, or any protection against chemical or biological attacks. See also NBC Shelter.
Faraday Cage: An area surrounded by metal that can conduct electricity well. Electricity from outside will hit the metal and loop through it, rather than going inside, protecting what is inside from the electricity. A Faraday cage can be used to block EMPs. Steel shelters usually act as Faraday cages.
Freeze Dried: Food that has the water removed first by freezing it, and then a vacuum removes the water. Freeze dried food will store for longer than dehydrated food. See also Dehydrated.
Gas Spring: A device that is attached to a blast hatch that can push the door open in case there is heavy debris on top of it that prevents it from being pushed open manually. Also called Debris Jack.
Ground Burst: A nuclear detonation that occurs on or near the ground. A ground burst causes material from the ground to be vaporized and later become fallout. See also Air Burst.
Ground Slap: Heavy pressure against the ground when an explosion occurs in the air. An explosion that occurs on the ground generates air pressure up and to the sides (it is blocked by the ground below). But an explosion in the air will generate air pressure in every direction. The downwards pressure to the ground creates the group slap.
HEMP: High Altitude Electromagnetic Pulse. When a nuclear device is detonated at a high altitude, the effects can cover a very large area. It is estimated that a nuclear explosion at about 300 miles (480km) above the United States could generate an EMP effect throughout the entire country, causing damage to most electronic equipment. See also EMP.
HVL: Halving Layer. The amount of a material required to reduce gamma radiation in half. Concrete has a HVL of 2.2" (5.5cm), so 2.2" of concrete will block 1/2 of all gamma radiation (and therefore has a PF of 2). Dirt has a HVL of 3.3". See also Protection Factor.
Improvised Shelter: See Expedient Shelter.
Initial Radiation: The radiation that occurs immediately when a nuclear bomb is detonated (as compared to radiation that occurs from fallout). See also Residual Radiation.
Intake Pipe: See Ventilation Pipe.
KI: The chemical symbol for Potassium Iodide. See also Potassium Iodide.
Manual Crank: A backup on an NBC filtration system that allows you to bring fresh air into the shelter by turning a crank, in case there is no electricity for the filter to work automatically. Also called Crank Handle.
Meal Ready to Eat: See MRE.
Mountain House: A company that manufactures #10 cans of food for long-term (25+ year) storage. They specialize in entrees, and have been around longer than their competition. See also #10 Can.
MRE: Meal Ready to Eat. This is food suitable for long-term storage, that looks like regular cooked food, and requires no preparation (unlike most food for long-term storage, that requires cooking or water). They were designed for the military, but are suitable for long-term food storage (although they can take up a lot of room).
NBC: Nuclear, Biological, Chemical. These are the three main threats that NBC shelters are designed to protect against. See also Biological, Chemical, Nuclear.
NBC Filter: A ventilation system that filters the air that comes into a shelter. It is designed to block dangerous chemicals, biological agents, and dust that could contain nuclear radiation.
NBC Shelter: A shelter designed to protect against nuclear, biological, and chemical threats. Such a design also allows it to protect against other threats, such as many natural disasters. See also Fallout Shelter, Bomb Shelter.
Negative Pressure: When a shelter is set up with pressure less than that of the outside air, so outside air comes into the shelter. This is normally undesirable, but could be used if the air inside the shelter was more contaminated than the air outside. See also Positive Pressure.
Nuclear: Any threat involving nuclear reactions. This threat includes nuclear bombs, 'dirty bombs', EMPs and failures at nuclear power plants.
Outflow Pipe: See Ventilation Pipe.
Overpressure: An air filtration system design that keeps the air pressure in the shelter greater than that outside the shelter. This ensures that if there are any leaks in the shelter (for example, the blast door not providing a completely airtight seal), air from the shelter will leave through those holes, rather than having contaminated air enter the shelter. See also NBC Filter. Same as Positive Pressure. See also Negative Pressure.
Overpressure Valve: A valve that is normally closed, but will open when the air pressure inside the shelter is greater than the air pressure outside the shelter. See Overpressure.
PF: See Protection Factor.
Positive Pressure: See Overpressure.
Potassium Iodide: A type of white salt that can be stored in tablets, which can be taken to protect damage to the thyroid from fallout. It provides the most protection if taken at least 1/2 hour before exposure to the fallout. It protects against fallout that is ingested, but does not protect against gamma radiation from fallout that is nearby (which requires significant distance and/or heavy materials such as concrete or dirt blocking the radiation). Also called KI.
Pouch: One of the ways that foods with a long shelf life are stored. Pouches do not have as long of a shelf life as #10 cans, but can last as long as about 10 years. See also #10 Can.
Primary Target: In the event of a nuclear war, where many nuclear bombs are detonated, the enemy will strategically choose where the detonations occur. Primary targets include military bases and larger airports. See also Secondary Target.
Protection Factor: A way of determining how effective materials are at blocking gamma radiation. It indicates the fraction of gamma radiation that is not absorbed. For example, 12 inches of concrete provides a protection factor of about 10 (with 1 in 10, or 10%, of gamma particles getting through), and 24 inches of concrete providing a PF of about 100 (with 1 in 100, or 1%, of gamma particles getting through). Also called PF. See also HVL.
Provident Pantry: A private label brand of #10 cans of food for long-term storage, sold by Emergency Essentials.
Provident Provisions: A private label brand of #10 cans of food for long-term storage, sold mainly by Emergency Preparedness Center.
PSI: A unit of pressure. Most shelters are designed to withstand at least 50PSI (about 3.4bar, or about 3.4 times the normal pressure of air at sea level). See also Bar.
Radiation: This usually refers to gamma radiation, which is emitted by the initial nuclear blast and by fallout that occurs afterwards.
Reinforced Concrete: Concrete that has some type of reinforcement, which usually consists of steel bars (rebar). These bars help make the concrete stronger.
Rem: "R�ntgen Equivalent in Man." This is a unit of radiation. 1 rem equals 0.01 sievert (Sv). 100rem (1Sv) can cause nausea, 200-500rem will cause hair loss, and can cause death. Over 300rem is fatal in 50% of cases within 30 days. Over 600rem almost always leads to death.
Residual Radiation: Radiation that occurs after a nuclear device detonates. This includes fallout. See also Fallout, Initial Radiation.
Risk Assessment: A detailed look into your location, and what threats are most likely. For example, if you live near (but not in) a very large city, you might assume that you would be safe from a nuclear blast, but very concerned with radiation.
Rock Crib: A bed of rocks that can be set up to surround the ventilation pipes. This helps reduce the pressure of a blast. It can also be used to help disguise the ventilation pipes.
Secondary Target: In the event of a nuclear war, where many nuclear bombs are detonated, the enemy will strategically choose where the detonations occur. Secondary targets are those that, if spared, would help allow the enemy to occupy the area they target (so they might not want to destroy these). They include dams, hospitals and power plants. See also Primary Target.
Shelf Life: The length of time that food or water will last. This depends on a number of factors, such as how it is stored and the temperature it is stored at (the colder the better). Some manufactured and well-packed foods have shelf lives up to 25-35 years. After the shelf life is reached, the taste, appearance, and/or nutrition may degrade (but should still be edible for a long time).
Shielding: Any material that blocks radiation. A shelter typically uses dirt and concrete as shielding to help block gamma radiation. See also Protection Factor.
TACDA: The American Civil Defense Association, a non-profit organization formed in 1962. It aims to educate the public about existing dangers and potential threats, providing products and services, and providing local and national resources.
Thrive: A company that manufactures #10 cans of food for long-term storage. They specialize in having a wide variety of foods (such as grains, fruits, and vegetables) at a low cost. Some of their foods have a long 25+ year shelf life, many others have a lower shelf life of 8 years (or less). See also #10 Can.
Vaccuum Wave: A wave of negative pressure that comes immediately following a high pressure blast after a nuclear detonation. The high pressure blast pushes air away from the site of the detonation, leaving empty space that needs to be filled in with air, causing the vacuum.
Ventilation: The movement of air within a shelter, allowing fresh (perhaps filtered) air in, and stale air out. See also NBC Filter.
Ventilation Pipe: A small pipe that either brings outside air into the shelter (intake pipe), or removes air from the shelter (outflow pipe).
Year Supply: Some companies that sell survival food offer enough food for one person to eat for a year, called a "Year Supply." However, this term can also refer to 730 entrees (lunch and dinner for a year), which is not near the calorie intake people are used to. So well designed "Year Supply" packages also include snacks, breakfast, drinks, side 14dishes, etc.