Flash point, definition

The flash point of PPS, as measured by ASTM D1929, is greater than 500°C. Combustion products of PPS include carbon, sulfur oxides, and carbonyl sulfide. Specific hazards are defined by the OSHA Hazard Communication Standard (158). Based on information in 1995, PPS does not meet any of the hazard definitions of this standard. 

The flash point represents the minimum temperature at whieh an ignitable mixture exists above a liquid surfaee. By definition, flash points are inapplieable to gases. Some solids, e.g. naphtlialene and eamphor, are easily volatilized on heating so that flammable mixtures develop above the solid surfaee and henee flash points ean be determined. (However, although these substanees ean be ignited, they generally need to be heated above their flash points in order for eombustion to be sustained this is the fire point .)... 

Stable in acidic, neutral and basic aqueous solutions Pale yellowish solid, faint characteristic odor Flash point 119°C (Pensky-Martens closed tester) Pyriproxyfen is an insect growth regulator which acts both as an ovacide and as an inhibitor of development (juvenile hormone mimic) against white flies, scale, and psylla. The specificity of pyriproxyfen, and its low mammalian toxicity, allow for some variation in application timing. For example, the lack of toxicity to bees allows pyriproxyfen to be applied during bloom on apple trees, and its low mammalian toxicity allows for a very short pre-harvest interval on citrus The residue definition is for pyriproxyfen alone... 

There are several standard tests for determining the flammability of materials (ASTM, 2004). For example, the upper and lower concentration limits for the flammability of chemicals and waste can be determined by standard test methods (ASTM D4982, E681), as can the combustibility and the flash point (ASTM D1310, E176, E502). With these definitions in mind it is possible to divide ignitable materials into two subclasses ... 

Following OSHA definitions, a flammable material is any liquid having a flash point below 100°F. The NFPA expands this definition by including the stipulation that the vapor cannot exceed 40 psi... 

It is important to note that the extinguishing techniques, controlling actions, or fire-prevention activities implemented can differ greatly depending upon which of the two categories the liquid falls in. To have the ability to categorize a liquid correctly when it is not so identified, it is only necessary to know its flash point. By definition, the flash point of a liquid determines whether a liquid is flammable or combustible. 

Nonflammable indicates that no flash point was observed by the ASTM test method D-3278-82 or D-56 below the boiling point of the solvent mixture or below 100°F, whichever is lower (this is the DOT, ANSI, and NFPA definition). The composition of liquid blends can vary from the originally supplied composition during use, owing to tile differing vapor pressures of the individual constituents. Care must be taken to avoid preferential loss of PFCs, which would result in flammable mixtures. 

This is used principally for the manufacture of cordite. It sitould be free from foreign matter, scales and particles, and. should have a flash point of at least 400 F. (205 C.) and a sp. gr. of not less than 0 87 at too I. (37 8 C.). It should not lose more than 0 2 per cent, in weight on heating for 12 hours on a water-bath and should be practically free from mineral matter. The acidity may be tested by dissolving in ether, allowing to settle and titrating a measured portion of the liquid with alcoholic potassium hydroxide. The mineral jelly should be practically neutral. Mineral jelly has no definite melting point. It is impt)rtant that the mineral jelly shall not have... 

A flammable liquid is generally considered to be one with a flash point below 55°C but above 2rC a highly flammable liquid is one with a flash point above 0°C and below 21°C any liquid with a flash point lower than 0°C and a boiling point lower than 35°C must be labelled extremely flammable. These are the definitions used here but it should be noted that the term extremely flammable is sometimes used for liquids with a flash point below 32°C. 

Flammable liquids or gases and meet the definition of the OSHA Hazard Communication standard [A-7] as a liquid having a flash point <100°F or a gas having a lower flammable limit of 13% by volume or having a flammable range that is wider than 12% by volume. The OSHA Threshold Quantity for flammable liquids and gases is 10,000 pounds. 

Ignitable—Based upon the flash point of a liquid waste for a solid, the capability to cause fire through friction or absorption of moisture, and to bum vigorously and persistently solids that meet the 49 CFR definition of oxidizer and, compressed gases that are ignitable under the DOT definition. 

Flash point is the temperature a liquid must be at before it will provide the fuel vapor required for a fire to ignite. A more technical definition for flash point is the lowest temperature a liquid may be at and still have the capability of liberating flanunable vapors at a... 

It should be noted that the U.S. OSHA and U.S. DOT have differing definitions for the terms flammable and combustible. DOT defines a flammable liquid as one that, under specified procedures, has a flash point of not more than 141°F/60.5°C. A combustible liquid is defined as one having a flash point above 141 °F/60.5°C and below 200°F/93°C. This definition is used in this book. Many experts use 100°F/37.8°C as the point to differentiate these... 

For the purposes of the regulation a combustible liquid is defined as any liquid that does not meet the definition of any other classification specified in the regulation and has a flash point at or above 100°F (37.8°C) and below 200°F (93.3°C) except any mixture having one component or more with a flash point at 200°F (93.3°C) or higher, that makes up at least 99 percent of the total volume of the mixture. 

For the piuqx)ses of the regulation an aqueous solution containing 24 percent or less alcohol by volume is considered to have a flash point no less than 100°F (37.8°C) if the remainder of the solution does not meet the definition of a hazardous material as defined in this subchapter. 

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