Requirements for Smokes

The smoke may be produced from a large number of chemicals in a variety of ways. However, only a few meet the specific requirements for a military smoke. 

The ideal military smoke or smoke material should be  

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Smoke. A few Member States have a regulatory requirement for smoke... 

Phosphorus containing compounds offer another route to provide halogen-free flame retardancy in thermoset composites. Ammonium polyphosphate materials promote carbonaceous chars that are bound into a vitreous coating formed by the polyphosphate decomposition products. The smoke density emitted from such systems in a fire easily satisfies the requirements of the German Bundesbahn, the French Epiradiateur test for irradiated surfaces, and Airbus requirements for smoke and toxicity. 

In July SWPA pressed the War Department for the immediate shipment of the two smoke companies and speculated on the reduced requirement for smoke pots if three smoke generator battalions were assigned. People in the Southwest Pacific Area were also concerned with the possibility that the two companies, which by September had not yet arrived, would be equipped with the 3,000-pound Mi generator, instead of the new lightweight Ma. Meanwhile, in response to the... 

Smoke is a complex mixture of gases, liquids and solid particles depending on the material that is burning and on the conditions of combustion. Each of the constituents of smoke displays particular optical and physical properties which are exploited in the two main types of detectors - optical and ionisation. Aspirating smoke detectors use either optical or ionisation detectors. The general requirements for fire alarm smoke detectors are contained in BS EN 54 with detailed requirements for smoke detectors covered in Part 7. 

One of the earliest questions studied by the USCWC was the coordination of Anglo-American requirements for smoke-producing materials. Even before the formation of the USCWC in 1942 the United States and Great Britain had begun talks on this subject. Later, the invasion of French North Africa brought with it a need for smoke pots to screen the ports against German air attack. In the summer of 1943 the U.S. Army did not... 

Stores should be specially designed, constructed of non-combustible material, and located away from other hazards (e.g. brick coal bunkers are suitable for small samples, but purpose-built constructions with explosion-proof lights etc. are required for larger quantities). They should be designated No Smoking areas and be well labelled. 

The use of automatically closing valves operated from gas-, fire- or smoke-detection systems is not normally required for gas installations. The reasons for this are ... 

Radioisotope-labeled nitrosamines have proven valuable in development of analytical methods and for demonstrating efficiency of recovery of nitrosamines from tobacco products and smoke (37-39). The very high specific activity required for low part-per-billion determinations has discouraged most analysts from using this approach. Unless a radiochromatographic detector with adequate sensitivity is available, samples must be counted independently of the final chromatographic determination, and one of the advantages of internal standardization, correction for variation in volume injected, is lost. 

Because of the lack of suitable standard rate of heat, smoke and toxic gas generation tests, the 1988 UK regulations are based on ignition resistance of individual materials. This contradicts the basic requirements for the fire testing of composites and of hazard related tests and as such it may be possible to develop materials which meet the requirements but which produce hazardous products. 

It is of interest to calculate, too the time required for both the fire itself and the thermal decomposition of the plenum PVC products to produce a lethal atmosphere. Table III presents such results for the fire, for heats of combustion of 20 kJ/g and 40 kJ/g, a range typical of most fires. In order to carry out this calculation it is assumed that the smoke is distributed instantaneously throughout the volume being considered, one or four room-plenums. The barriers represented by walls or... 

It is clear that the "time to lethal concentration" for the smoke from any of the PVC products in the plenum, in all the six scenarios considered, is much longer than the time required for the fuel in the room itself to cause a lethal concentration in the same scenario. 

The excellent detection ability for flames makes UV sensing a good method for remote fire alarm-monitoring. UV radiation after the outbreak of a fire reaches a sensor much faster than heat or smoke. Also, the distance between sensor and fire is less critical. Requirements for the sensor are high sensitivity and excellent selectivity. Radiation intensities at the sensor position may be even lower and the ambient light conditions less restricted than for combustion controlling. When used outside, solar-blindness is a must. These stringent requirements make UV fire alarm monitors expensive, and they are used in industrial environments such as production floors or warehouses rather than in private homes. 

R.J, Reynolds (RJR) maintained a nicotine optimization program, the goals of which were to define the optimum nicotine level in cigarette smoke required to maximize smoker satisfaction as well as a minimum or threshold value of nicotine required for satisfaction (Piehl 1978 R.J, Reynolds 1989),... 

While nicotine is the primary active pharmacological agent, tobacco has been shown to be a particularly effective vehicle for delivery of nicotine (US Food and Drug Administration 1995 Hurt and Robertson 1998 Slade et al. 1995 World Health Organization 2001). In fact, published research has determined that tobacco-delivered nicotine is not only more toxic, but more addictive than nicotine in a pure form (e.g., nicotine replacement therapy) (Henningfleld et al. 2000 Royal College of Physicians 2000). As noted by a BW scientist in 1990 Nicotine alone in smoke is not practical, nor are extreme tar/nicotine ratios, since nicotine is too irritating -other substances are required for sensoric reasons (Baker 1990). 

Titanium (IV) tetrachloride (TiCy produces a dense white smoke-like vapor when exposed to moist air. It is used as smoke screens and for skywriting, as well in theatrical productions where fog or smoke is required for the scene. 

AP composite propellants without aluminum particles are termed reduced-smoke propellants and are employed in tactical missiles to conceal their launch site and flight trajectory. No visible smoke is formed when the relative humidity of the atmosphere is less than about 40%. However, since high-frequency combustion oscillation tends to occur in the combustion chamber in the absence of solid particles that serve to absorb the oscillatory energy, a mass fraction of 0.01-0.05 of metallic particles is still required for the reduced-smoke propellants. These particles and/or their oxide particles generate thin smoke trails. The white smoke trail includes the white fog generated by the HCl molecules and the condensed water vapor of the humid atmosphere. 

Second hand marijuana smoke in a car can cause you to fail the next day (Nightbyrd). It is possible that second hand [marijuana] smoke will raise someone to the 50 ng/mL level however, extreme exposure is required. For instance, a closed car full of pot smokers and a non-smoker may render the non-smoker positive for both urinalysis and the hair test, provided that they are sealed in the car for a while. The Army did a case study where volunteers were put in a room pumped full of smoke for an hour, five times daily. Subjects started testing positive after the second day. The non-smoker would have to take in virtually as much second hand smoke as a smoker inhales. Non-smokers are safe in a ventilated area, as long as they don t get a hair test. According to Clinton, simply blowing crack smoke on ones hair may cause a positive hair test. Second hand pot smoke doesn t affect the hair test results as much as crack smoke does mainly because exhaled smoke contains no THC. The only pot smoke that contains THC is the smoke that hasn t entered the lungs. 

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