Smokes formulations

Gun Propellents. Although the stresses on individual gun propellant grains are less severe because of the small size, these propellants must withstand much higher weapon pressures and accelerations. Formulation options are usually more limited for gun propellants than for rocket propellants because the products of combustion must not foul or corrode a gun, should have a low flame temperature, and should exhibit minimum flash and smoke characteristics. Gun propellants are examined microscopically for porosity, are tested for mechanical characteristics, and fired in closed bombs to determine the burning characteristics. 

Alumina trihydtate is also used as a secondary flame retardant and smoke suppressant for flexible poly(vinyl chloride) and polyolefin formulations in which antimony and a halogen ate used. The addition of minor amounts of either zinc borate or phosphoms results in the formation of glasses which insulate the unbumed polymer from the flame (21). 

Effects on Visible Smoke. Smoke is a main impediment to egress from a burning building. Although some examples are known where specific phosphoms flame retardants increased smoke in small-scale tests, other instances are reported where the presence of the retardant reduced smoke. The effect appears to be a complex function of burning conditions and of other ingredients in the formulation (153,156,157). In a carehil Japanese study, ammonium phosphate raised or lowered the smoke from wood depending on pyrolysis temperature (158). Where the phosphoms flame retardant functions by char enhancement, lower smoke levels are likely to be observed. 

The PVC formulations shown in Table 2 represent typical compounds used by the wine and cable industry. PVC compounders have developed new PVC-based formulations with very good fire and smoke properties (can pass the UL 910 Steiner Tunnel test) that compete with the more expensive fluoropolymers. These can be used in fabricating telecommunication cables usable for plenum area appHcations. 

Flame and Smoke Retardants. Molybdenum compounds are used extensively as flame retardants (qv) (93,94) in the formulation of halogenated polymers such as PVC, polyolefins, and other plastics elastomers and fabrics. An incentive for the use of molybdenum oxide and other molybdenum smoke and flame retardants is the elimination of the use of arsenic trioxide. Although hydrated inorganics are often used as flame retardants, and thought to work by releasing water of crystallization, anhydrous molybdenum oxides are effective. Presumably the molybdenum oxides rapidly form... 

Proprietary blend formulations based on polysulfone, polyethersulfone, and polyphenylsulfone are sold commercially by Amoco Corporation to meet various end use requirements. The blends based on polysulfone are sold under the MINDEL trademark. A glass fiber-reinforced blend based on PES is offered under the trade name RADEL AG-360. This offers most of the performance characteristics of 30% glass fiber-reinforced polyethersulfone but at a lower cost. Two blend product lines are offered based on PPSF. These are designated as the RADEL R-4000 and R-7000 series of products. The former is a lower cost alternative to RADEL R PPSF homopolymer offering most of the performance attributes unique to PPSF. The R-7000 series of resins have been formulated for use in aircraft interiors for civil air transport. They exhibit a very high degree of resistance to flammabihty and smoke release. 

Uses. Inactive dried yeasts are used as iagredients ia many formulated foods baby foods, soups, gravies, and meat extenders as carriers of spice and smoke flavors and ia baked goods. Yeasts used ia the health food iadustry are geaeraHy fortified with minerals and contain higher concentrations of the B vitamins, especially thiamin, riboflavin, and niacia (see Vitamins). 

Other uses of hexachloroethane are as moth repellent, plasticizer for cellulose esters, anthelmintic in veterinary medicine, mbber accelerator, and as a component in fungicidal and insecticidal formulations. Hexachloroethane reacts with silumin (an aluminum /siUcon alloy) at 483 K to generate an intense white smoke, which is useful in certain pyrotechnics (154). 

Other flame retardants and/or smoke suppressants can also be used such as magnesium hydroxide, magnesium carbonate, magnesium-zinc complexes and some tin-zinc compositions. Zinc oxide is a common ingredient in many rubber base formulations used as part of the curing system. At the same time, the action of zinc oxide is similar to that of antimony trioxide, but less effective. 

Oxamide has been used as a stabilizer for NC prepns (Ref 6), as a coolant in propint formulations because the amt of smoke contributed by it was small (Ref 2), and as a component of Oxamide Explosive Composition (see below)... 

Red P has been employed as an ingredient of pyrotechnic smoke, delay and safety match formulations (Refs 1,2,3 4). White smoke consisting of small droplets of phosphoric acid have been widely used for military purposes. 

Si, and stannic tetrachloride. An effective smoke agent, whether it be mechanically dispersed from an aircraft spray tank or vaporized thermally, is a mixt of S trioxide and chlorosulfonic acid (FS smoke agent) which upon hydrolysis forms sulfuric and hydrochloric acid dispersions. Of course, all such formulations are highly corrosive, and, if not outright toxic, then conducive to pulmonary edema... 

Among the agricultural chemicals used for the cultivation of tobacco crops we find several amines, amides and carbamates. These include dimethyldodecylamine acetate (Penar), maleic hydra-zide-diethanolamine (MH-30), and carbaryl (Sevin) as a representative of the methyl urethanes (Figure 3 , 14), It is known that small quantities of these agents are found as residues in harvested tobacco (15). To date, only diethanolamine (DELA), the water-solubilizer for maleic hydrazide in MH-30, has been studied as a possible precursor for nitrosamines in tobacco and in tobacco smoke. In 1976, more than 1,400 metric tons of maleic hydrazide had been used on U.S. tobacco (16), most of which had been applied as the MH-30 formulation with diethanolamine (14,16). 

Thus, we conclude that the diethanolamine in MH-30 is the major precursor for NDELA in processed U.S. tobaccos and tobacco smoke. In fact, NDELA concentrations of 600-1,900 ppb were already present in five agricultural spray formulations of MH-30 which we analyzed (19). 

Polyester thermosets can be formulated to meet a wide range of flame, smoke, and toxicity specifications. 

Earlier studies at the ITRI have demonstrated the effectiveness of tin(IV) oxide, both in its anhydrous and hydrous forms, as a flame- and smoke-retardant additive for laboratory-prepared polyester resin formulations (J5j. In a recent study, carried out in collaboration with a major U.K. company, a number of inorganic tin additives have been incorporated into a commercial brominated polyester resin. Although this resin, which contains 28% by weight bromine, is intrinsically flame-retardant, giving samples with an 01 of ca. 41 and which meet the UL94-VO classification, formulations with improved flame and smoke properties are sought. 

Hence, it is apparent that certain inorganic tin compounds are very effective flame retardants and smoke suppressants for halogenated polymer formulations. Since these additives are generally non-toxic, their potential use as partial or total replacements for existing commercial flame retardants, such as antimony trioxide, is thought to merit serious consideration. 

Assessment and reduction in the use of alcohol, tobacco, and other substances prior to pregnancy improve outcomes. For smoking cessation, behavioral interventions are preferred. Intermittent delivery formulations of nicotine replacement therapies are preferred over the patches. If patches are used, 16-hour patches are preferred over 24-hour patches. 

---