Aerosol container

The word propellant is also used for the liquefied gas in a pressurized aerosol container. 

The aerosol container has enjoyed commercial success ia a wide variety of product categories. Insecticide aerosols were iatroduced ia the late 1940s. Additional commodities, including shave foams, hair sprays, antiperspirants, deodorants, paints, spray starch, colognes, perfumes, whipped cream, and automotive products, followed ia the 1950s. Mediciaal metered-dose aerosol products have also been developed for use ia the treatment of asthma, migraine headaches, and angiaa. 

Product Concentrate. An aerosol s product concentrate contains the active ingredient and any solvent or filler necessary. Various propellent and valve systems, which must consider the solvency and viscosity of the concentrate—propellent blend, may be used to deUver the product from the aerosol container. Systems can be formulated as solutions, emulsions, dispersions, or pastes. 

LujuePed Gas Propellants. One of the advantages in using a Hquefied gas propeUant is that the pressure in the aerosol container remains constant until the contents are completely expeUed. The disadvantages are primarily ones of safety and environmental impact. 

Compressed Ga.s PropeIIa.nts. The compressed gas propellants, so named because they are gaseous in conventional aerosol containers, are nontoxic, nonflammable, low in cost, and very inert. When used in aerosols, however, the pressure in the container drops as the contents are depleted. Although the problem is lessened when the contents are materials in which the propellant is somewhat soluble, this pressure drop may cause changes in the rate and characteristics of the aerosol spray. A compressed gas aerosol system is illustrated in Figure 3. 

Containers. Aerosol containers, made to withstand a certain amount of pressure, vary in both size and materials of constmction. They are manufactured from tin-plated steel, aluminum, and glass. The most popular aerosol container is the three-piece tin-plated steel container. Glass containers, which are usually plastic coated, generally have thicker walls than conventional glass jars. They are limited to a maximum size of 120 mL and are used for pharmaceutical and cosmetic aerosols. 

Aerosols. Pressurized containers to deHver aerosolized dmg products through appropriate systems of valves and actuators have been available since the 1950s (see Aerosols). Such dosage forms are used as external appHcations of lotions and creams, for oral inhalation, or for treatment of the vaginal cavity, eg, contraceptive foams. Aerosols contain two- or three-phase systems, wherein a volatile Hquid or admixture of Hquids is sealed in a... 

In addition to the packaging of foods and beverages in regular containers, a large quantity of tinplate is used in the form of aerosol containers for cosmetics, paint, insecticides, poHshes, and other products. Decorative trays, Hthographed boxes, and containers of unusual shape are additional oudets for tinplate. 

Dry methylene chloride does not react with the common metals under normal conditions however, a reaction with aluminum can be initiated, sometimes explosively, by the addition of small amounts of other halogenated solvents or an aromatic solvent (7). Iron catalyzes the reaction, and this can be significant in the handling and storage of methylene chloride and in the formulation of products, eg, in aluminum aerosol containers of pigmented paints, where the conditions necessary for the reaction are commonly found. A typical reaction in this process is shown in equation 2. 

An aerosol container can be considered a special appHcation of airless atomization (see Aerosols). The pressure is usually suppHed by a Hquefied gas in the container at its equiUbrium pressure. The material being sprayed has a very low viscosity to provide easy material flow through the feed tube and to permit fine atomization. 

Amongst the many other applications for acetal resins should be mentioned links in conveyor belts, moulded sprockets and chains, blower wheels, cams, fan blades, check valves, pump impellers, carburettor bodies, blow-moulded aerosol containers and plumbing components such as valve stems and shower heads. 

Articles made from polyacetals vary from door handles to gears and bushings, carburetor parts to aerosol containers. The major use of polyacetals is for molded grades. 

Respirators should comply with BS 2091, BS 4555, BS 4558, BS 4771 and BS 4275. (Refer to Form F2486, published by HSE for suppliers of respirators suitable for use against aerosols containing Legionella.)... 

True. Most aerosols contain flammable gas under high pressure. They can also explode if burnt, even when apparently empty. 

Assume that the aerosol contains a liquid of flammability equivalent to that of petrol and treat it as such. 

For aerosols of nonvolatile pesticides (e.g., paraquat) and aerosols containing pesticides, sampling methods consisting of filtration and employing inertial samplers... 

Static aerosol challenge Expose sealed containers to periodic challenge by generating aerosol containing the challenge organism... 

Aeromonas, DNA-based biosensor, 3 807 AeroSizer, 78 150—151 Aerosol containers, 7 781-782 Aerosol dispersions, 7 774-775 Aerosol drug dosage forms, 78 717 Aerosol emulsions, 7 773, 774 Aerosol flow reactors, 77 211-212 Aerosol foams, 7 773, 774 Aerosol packaging, 7 771 Aerosol pastes, 7 775 Aerosols, 7 769-787 8 697 economic aspects, 7 786 filling, 7 785-786 formulation, 7 771-780 product concentrate, 7 772-775 propellants, 7 775-781 U.S. production, 1985-2000, 7 770t Aerosol solutions, 7 772-773 Aerosol solvent extraction system (ASES), 24 17, 18... 

Apart from the economic significance of such loss there are potentially adverse effects on the environment arising from acidification of rain and soil. Ammonia may react with hydroxyl radicals in the atmosphere to produce NOx contributing to the acidification of rain (4). Wet and dry deposition of NH3/NH4+ inevitably contributes to soil acidification through their subsequent nitrification. This effect can be accentuated in woodland by absorption of aerosols containing NH4+ within the canopy followed by transport to the soil in stem flow (5). In more extreme cases, NH3 emission from feedlots, pig and poultry... 

Body weight effects were not observed in adult female Harlan Wistar rats exposed to an aerosol containing 234 ppm phenol for 8 hours (Flickinger 1976), nor in rats exposed continuously to 26 ppm phenol in air for 15 days (Dalin and Kristoffersson 1974), nor in rhesus monkeys, rats, or mice exposed continuously to 5 ppm phenol in air for 90 days (Sandage 1961). 

FIG. 1. Fast 1 -min SPECT coronal-section lung images of a healthy subject after inhalation of normal saline aerosols containing TC-DTPA in large and small droplet sizes (7 im, top panel 3 pm, bottom panel) generated by air jet nebulizers. The difference in deposition between the two aerosols is clearly shown in these images. 

The canister adapter sleeve must be placed on each canister before the system can transfer it from station to station. The canister adapter sleeve is made from Delrin and has an inside diameter sized to fit a particular aerosol container and valve. An O-ring or hp-type seal helps to centre and restrict relative motion of the canister within the sleeve. The outside shape and dimensions are constant for each canister size. 

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