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Chemical disaster or war survival

 
EMPerror
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User ID: 8804293
Lithuania
05/10/2013 12:55 PM
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Chemical disaster or war survival
Chemical dangers are not widely known. People often have no awareness about these dangers that are unavoidable. Dangers come from various industries, fire disasters, volcanoes, and possibility of chemical war. The only sure way to protect oneself or family is evacuation from disaster zone or evacuation to the shelter capable to survive such disaster. To do that, real-time situation awareness about winds and contaminations involved is needed. It may not be available until you end up in a contaminated place. Personal chemical protection may be important factor for survival and reduction of health effects until safe place is reached.
First signs of disaster can be given out by pets as some of them can smell extremely small concentrations of chemicals that humans may not be aware at all. Other signs may be dying or discolored vegetation, strange smell, animals acting in unusual ways and some chemical sensors (like carbon monoxide alarm) going off without any reason.

Danger depends on chemical which is involved. Different disaster causes can have different outcomes and thus for each of them preparation or planning in advance may be needed.

Volcanoes emit poison gases most of which are acidic and dangerous dust. Gases include sulfur dioxide (SO2), carbon monoxide (CO), hydrogen sulfide (H2S) and numerous other. Volcano gases have high carbon dioxide (CO2) content, may be extremely hot in the vicinity which makes any filtration system useless. Acid gas and CO filters may help in some less severe situations, reduce health effects and save lives. Casualties from poison gases alone are close to 3%. Volcano dust is extremely dangerous and improved particle filter is a must at any distance where dust can travel.

Uncontrollable fires are extremely dangerous in towns, cities and near chemical storage areas (like pesticide, herbicide) as there they can cause widespread chemical contamination. Some of these fires may not be so poisonous by themselves (as hot gases rise up) than fallout from them on the soil which later can end up in food or drinking water. Chemical air filtration can be used during fires as long as air has low CO2 content, high oxygen (O2) and filtration offers protection against CO and hot air. Improved particle filter is also needed.
Shelters usually are made with fire hazard in mind as war is direct cause for uncontrollable fires. Although depth, thermal protection and air supply must be taken into account and reviewed. Shelters that are in the forest, urban areas that can easily burn for extended time periods are at risk as fire can heat up ground, entrance significantly. Plastic or rubber parts can melt or burn with all the consequences. Shelters not deep enough may become too hot from fire raging above. Air supply from above during fire may not be possible and adequate air supply for such event is needed.

Some disasters can disrupt electrical grid and are directly dangerous for industries that use cooled liquid gases. These gases can be flammable like methane (CH4) and have a risk of explosion, can cause fires, others are poisonous like liquid ammonia (NH3), SO2, chlorine (Cl2). With electrical grid down, and without backup energy source such gasses will eventually heat up and start evaporation. Air filtration may help with such disasters.

Air filtration can only reduce particle and chemical concentrations. Areas with high contamination concentrations can lead to filtration failure. When contaminants from passing air are absorbed in the filter, with time contamination leaking through filter is gradually increasing. The more polluted is air, the less protection time is left for such filter.
CO or catalyst filters work in a different way, they usually transform chemicals into non dangerous form by oxidizing and either use O2 or chemicals in the filter. Some catalyst filters have long life spans, but have a need for high temperatures to effectively operate. Personal CO filters have usually short limited lifespan.

Personal filters have limited weight and limited lifespan ranging from 20min to several hours (or more depending on chemical contaminant and concentration, filter used) after which filter must be changed or safe place reached. It is possible to calculate time of protection when contaminant concentration is known. Chemicals and their concentration detecting devices may be extremely handy in such situation as they can help to determine when to change filter without being poisoned.

From
[link to en.wikipedia.org]
[link to en.wikipedia.org]
and other links

Personal gas mask filters are marked with a letter and number:
AX - Low-boiling (≤65 °C) organic compounds (brown)
A - High-boiling (>65 °C) organic compounds (brown)
B - Inorganic gases (H2S, Cl2, HCN) (gray)
E - Acidic gases (SO2, HCl) (yellow)
K - Ammonia and amines (green)
CO - Carbon monoxide (black)
NOx - Nitrogen oxides (blue)
Hg - Mercury vapors (red)
SX - Specific compounds excluding CO NOx Hg (violet)

A,B,E,K are generic chemical types which may vary and must be specified by the manufacturer. Number after letter represents filter capacity class

With 30L/min air flow filter must pass test with various chemicals
Class 1 - low capacity, <1000ppm
A1 C6H12 >70min, leaking <10ppm
B1 Cl2 >20min, leaking <0.5ppm
B1 H2S >40min, leaking <10ppm
B1 HCN >25min, leaking <10ppm
E1 SO2 >20min, leaking <5ppm
K1 NH3 >50min, leaking <25ppm

Class 2 - medium capacity, <5000ppm
A2 C6H12 >35min, leaking <10ppm
B2 Cl2 >20min, leaking <0.5ppm
B2 H2S >40min, leaking <10ppm
B2 HCN >25min, leaking <10ppm
E2 SO2 >20min, leaking <5ppm
K2 NH3 >40min, leaking <25ppm

Class 3 - high capacity, <10,000ppm
A3 C6H12 >65min, leaking <10ppm
B3 Cl2 >30min, leaking <0.5ppm
B3 H2S >60min, leaking <10ppm
B3 HCN >35min, leaking <10ppm
E3 SO2 >30min, leaking <5ppm
K3 NH3 >60min, leaking <25ppm

Particle filtration is marked P (white):
P1 - Filters >80% of airborne particles
P2 - Filters >94% of airborne particles
P3 - Filters >99.95% of airborne particles

Particle filter protects not only against dust and aerosol particles, but also is a primary protection from radioactive particles.

There is also similar marking for disposable masks
FFP1 - Filters >80% of airborne particles
FFP2 - Filters >94% of airborne particles
FFP3 - Filters >99% of airborne particles

As an example for marking, chemical filter can be A1B2-P3, which means it protects against organic compounds (A) with class 1 capacity and against inorganic gases (B) with class 2 capacity and against particles (P3).
These classes are generic and can give a hint when choosing filter for certain situation. Filters usually have test data for each chemical separately. It can be used for finding filter change time.
[link to www.osha.gov]

Shelters usually have filters without weight or size restrictions that can last reasonable amounts of time. This time however is limited and can become a problem if air contamination lasts a long time or has much higher concentration than expected. Situation may force to change filters numerous times. Doing it in a way that prevents contamination leakage into shelter is critical.
Whenever air filtration fails, rebreather or pressurized air is needed. Shelters can use compressed air, or O2 supplement and CO2 removal. When air supply finally fails, shelter may have to be abandoned.
grumpier

User ID: 1189758
Netherlands
05/10/2013 01:07 PM
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Re: Chemical disaster or war survival
Thanks EMP for this post, I saved the date and will check on my gas masks later.

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EMPerror  (OP)

User ID: 8804293
Lithuania
05/10/2013 05:51 PM
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Re: Chemical disaster or war survival
Most military and some industrial chemical agents can have negative effects on the skin causing burns or pass directly through it causing poisoning. Some military agents are usually dispersed into small droplets that fall down and slowly evaporate. NBC suit with chemical resistant boots (rubber or plastic) is a must for protection against such threats.
Suit must be made from materials that do not dissolve or react with contaminants. Not all plastic or rubber materials are used or are suitable for this purpose. Some plastic or rubber materials are porous and can cause leakage of contamination. Manufacturers usually test chemical suits before and results of these tests often can be found online. Suit must be completely air and water proof.
In SHTF when NBC suit is not available any plastic rain coat sealed with duct tape is better than none. It is also possible seal yourself in a big plastic bag leaving only facial part of gas mask not sealed. Unfortunately this way movement will be limited with only one option remaining, to wait until wind will disperse contaminants which may not happen soon and it's an option of last resort.
NBC suits do have a risk of hyperthermia when weather is hot as they prevent evaporation. Both risk of hyperthermia and limited air filter lifespan or air supply should urge everyone seek safe place or suitable shelter as soon as possible.
When safe place is reached removal of gas mask may be a fatal mistake. It can be done only when contamination is known to be gas which does not stick to the suit or mask itself. Contaminants, disease germs, viruses, radioactive particles are usually brought on the suit and on the mask to the safe place and are no less dangerous than in contaminated place. A single missed drop of contaminant brought from contaminated place can have a potential of killing everyone in the shelter. The best way to deal with it is decontamination with gas mask and NBC suit on. It is done with bleach (sodium hypochlorite or NaClO) or other aggressive decontaminating chemical. Several of them can be used one after another as there is no universal decontaminating chemical, different contaminants have different decontaminating chemicals. Shelters should have a sealed place between doors, where before entering, you can have a spray of decontaminating/disinfecting chemical and possibly normal water shower after that. If NBC suit is not watertight then there is a risk of chemical burn from decontaminating agent. Burn or wound is one of the worst outcomes in such situation and should be avoided at all costs making full decontaminating shower out of the question. Then it's better to decontaminate without spaying so that it would not cause burns or only spots where it is needed, near gas mask, shoes, and spots where contact during removal of suit may happen. Partially decontaminated suit is dangerous and would have to be disposed of, left or decontaminated later wearing another gas mask and suit.
Removal of contaminated suit outside should be done so that exterior would not be touched and so that wind would be blowing anything coming from the suit away from you, not right into your face. Suit should be left and only when you walk away from it significant distance against the wind, gas mask can be removed. Before removal gas mask can be decontaminated again, to be sure. If it is done in the shelter, such suit should be sealed in an air tight container or bag and good disinfecting, or less aggressive (suitable for skin) decontaminating shower should be taken with a mask (mask must have been decontaminated before suit removal) on and only after that gas mask can be removed to take a shower without it. It's better to assume that disease germs or chemicals were on your skin and there was a risk of getting them into lungs if suit was not watertight.

Last Edited by EMPerror on 05/10/2013 05:56 PM
EMPerror  (OP)

User ID: 8804293
Lithuania
05/13/2013 06:31 PM
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Re: Chemical disaster or war survival
Old movie about protection against chemical agents, but still offers some basic knowledge. As antidotes may not be available, improved protection or steps to avoid accidental poisoning should be considered.


[link to www.youtube.com]


[link to www.youtube.com]





GLP