Flammability Hazards of Common Solvents

Flammable liquids are widely used in many types of factories, and their misuse is responsible for many outbreaks of fire. The fire risks from the flammable liquids in common use such as petrol, paraffin, white spirit, cellulose solutions and thinners are well known, but these are only a few of the liquids which present hazards in industry. The variety of flammable liquids used in processes as solvents or carriers and for other purposes is constantly extending. 

Some of the solvents that are commonly used in epoxy resins can present a flammability hazard and special health hazards. Contact with solvents will cause drying of the skin, which may result in an increased probability of skin irritation, especially when one comes in contact with curing agents. Solvents also have the ability to dissolve epoxy resin system components and carry them through the skin in liquid form or into the respiratory system in vapor form. The inhalation of solvent vapors or mist may cause respiratory irritation and... 

Most resinous materials used in epoxy adhesive are organic and will bum when sufficient heat and oxygen are supplied. A common measure of the flammability is the flash point temperature. This value indicates the minimum temperature at which flammable conditions are produced in controlled laboratory experiment at atmospheric pressure. Solvents, diluents, and other materials used with epoxy resins commonly increase the hazard of flammability and/or explosion. 

PIMs share considerable similarities with the more well-known liquid-liquid extraction techniques, commonly known as solvent extraction (SX), in which an extractant is dissolved in a large volume of solvent. PIMs are principally differentiated by the replacement of the solvent with a polymer matrix. Solvents used in SX are commonly volatile, toxic and flammable (e.g., kerosene, decane) and extractants are commonly corrosive and harmful to the environment if released (e.g., substituted aUcylamines, substituted alkylphosphorus compounds). By replacing the solvent with a relatively inert polymer matrix, the chemical hazards associated with separation processes are considerably reduced and solvent-associated fire hazards are essentially eliminated. Additionally, by entrapping the extractant in the polymer matrix, occupational exposure to the extractant could be considerably reduced. 

There are two main hazards associated with asphalt Fire and explosion hazards and health hazards associated with skin contact, eye contact, and/or inhalation of fumes and vapors. Most of the fire and explosion hazards associated with asphalt come from the vapors of the solvent mixed into the asphalt, not the asphalt itself The hazard is determined by the flammable or explosive nature of the solvent used and how fast it evaporates. The flash point (FP) of the asphalt and solvent mix will be higher than the FP of the solvent alone. Asphalt is combustible, typically with a FP of 204-288°C (400-550°F).The flash point—and therefore, the fire or explosion hazard— can be determined, in part, by the type of asphalt used.There are three types of cut asphalts. Rapid-curing asphalt (RC) is blended asphalt that has been cut with a low-flash (highly flammable) petroleum solvent. This low-flash solvent quickly evaporates, allowing the RC mixture to rapidly set and harden. Examples of solvents commonly used in RC mixtures include Benzene (FP=-11°C (12°F)), Dioxin (FP=27-32°C (81-90- F)), Naphtha (FP=42°C (107°F)),Toluene (FP=4°C (40°F)), and Xylene (FP=27-32°C (80-90°F)). Medium-curing asphalt (MC) is blended asphalt that has been cut with a solvent with a flash point over 170°F. Slow-curing asphalt (SC) is blended asphalt that has been cut with a low-flash oil having a flash point of over 12 PC (250 F). 

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