Fire

Fire is a rapid, simple, and effective method of decontaminating chemical and biological agents. Large quantities of contaminated items may be decontaminated and disposed of since fire vaporizes or destroys chemical and biological contamination; some chemical agents are combustible and will convert into relative harmless products while biological agents are killed or destroyed. Care must be exercised in that toxic fumes or vapors be not carried by the wind towards locations which may suffer contamination, hence the best conditions to use fire are in days with moderate wind, establishing the wind's direction so as to avoid spreading contamination to undesired localities downwind Materials contaminated by nuclear radiation will not be affected by fire even if the contaminated material itself may be destroyed by combustion.

Water

Fallout and biological agents may be removed with water, but some chemical agents won't. Water is more effective hot than cold and adding some detergent or soap makes it still more effective. At the same time precautionary measures should be observed that runoff water used for decontamination does not flow and decontaminate watercourses. Water alone will not decontaminate lewisite-type blistering agents and it will form a toxic blistering residue. Surfaces/items contaminated with lewisite-type blistering agents should scrubbed and soapy, hot water employed or an alkaline solution should be employed to remove the residue. Contamination is flushed away from surfaces and water hydrolyzes some chemical agents, however it is not as effective on porous or greasy surfaces since these surfaces tend to trap and hold contamination. Flushing will not affect contamination that has soaked in. Water's efficacy is increased with higher pressure, its temperature raised, soap or detergent added and more time given to the decontaminating task; if steam is used many microorganisms will be killed. Boiling in hot and soapy water is an excellent method of decontamination. Boil for 15 minutes, double the time at high altitudes. Autoclaving with a pressure-cooker device is an excellent decontamination method for biological contamination. Water may wash down radiological contaminated substances but it will not remove the contamination. To limit and collect contaminated runoff a sump should be employed.

A closing note concerning Chemical and Biological Weapons.

Biological weapons, along with chemical weapons, were banned by the Geneva Protocol of 1925 by "the prohibition of the use in war of asphyxiating, poisonous or other gases, and of bacteriological methods of warfare".
"The use of biological weapons" President Nixon said in 1969, "is repugnant to the conscience of mankind" and could produce "massive, unpredictable and potentially uncontrollable consequences".[1] This led to the 1972 Biological Weapons Convention, signed by the United States, the Soviet Union, and more than 100 other nations. Parties to the 1972 Convention agreed "never in any circumstances to develop, produce, stockpile or otherwise acquire or retain ... biological agents or toxins ... of types and in quantities to have no justification for prophylactic, protective or other peaceful purposes."

However, there are good reasons to suspect that things did not work along the meaning of words and official conventions, furthermore all formulas of chemical agents for warfare employment and detailed information are no secret: it takes only a good chemist, a well equipped laboratory and irresponsible governance to stockpile, secretly, chemical agents. The same may be said concerning biological agents, from bacillus anthracis (the bacterium that causes anthrax) to whatever biogenetic progress may have put in the hands of the military.

[1] White House Press Release, 1969. Remarks of the president announcing the chemical and biological defense policies and programs. November 25.