Safety flash point

No. 4 fuel oil a light indnstrial heating oil and is nsed where preheating is not required for handling or burning there are two grades of No. 4 fuel oil, differing in safety (flash point) and flow (viscosity) properties. 

Because of the uncertainty of the potential flammability of combustible liquids, they will be referred to as flammable liquids throughout this book. It is highly recommended that they be treated the same way on the incident scene for the purpose of responder and pnblic safety. Flash point will be discussed in detail later in this chapter. It is important, however, to note at this point that the flash point temperature is the most critical factor in determining if a flammable liquid will bum. The most important precantions are to control ignition sources at the incident scene and keep personnel from contacting the liquid without proper protective clothing. 

From an engineering perspective, in assessing the required characteristics of the biofuels themselves, one must consider a variety of chemical, physical, and environmental properties. These include factors such as total energy content, ease of ignition (quantified by octane and cetane numbers), heat release rates, evaporative spray characteristics (vapor pressures), flammability safety (flash point), flow properties (viscosity), density, miscibility, fuel toxicity, emissions, impact on engine parts, and stability in storage. 

Diesel Fuel Safety as Characterized by Its Flash Point... 

The flash point of a petroleum liquid is the temperature to which it must be brought so that the vapor evolved burns spontaneously in the presence of a flame. For diesel fuel, the test is conducted according to a closed cup technique (NF T 60-103). The French specifications stipulate that the flash point should be between 55°C and 120°C. That constitutes a safety criterion during storage and distribution operations. Moreover, from an official viewpoint, petroleum products are classified in several groups according to their flash points which should never be exceeded. 

It should be noted finally that adding gasoline to diesel fuel which was sometimes recommended in the past to improve cold behavior conflicts with the flash point specifications and presents a serious safety problem owing to the presence of a flammable mixture in the fuel tank airspace. Adding a kerosene that begins to boil at 150°C does not have the Scune disadvantage from this point of view. 

Safety standards govern the manipulation and storage of crude oil and petroleum products with regard to their flash points which are directly linked to vapor pressure. 

Health nd Safety Factors. Although propargyl alcohol is stable, violent reactions can occur in the presence of contaminants, particularly at elevated temperatures. Heating in undiluted form with bases or strong acids should be avoided. Weak acids have been used to stabilize propargyl alcohol prior to distillation. Since its flash point is low, the usual precautions against ignition of vapors should be observed. 

Fig. 14. Outside battery limit (OSBL) equipment spacing. Minimum spacing for off-site equipment is in meters. Classifications of tankage are Class 1 high ha2ard, flash point below 38°C Class 2 low ha2ard, flash point above 38°C. NFPA = National Fine Protection Association. Safety standards are calculated...

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed cup.

Like brines, alcohols were readily available and widely used as antifreeze Hquids in the early 1900s. Both methanol and ethanol offer exceUent heat transfer and efficient freeze point depression. However, the alcohols have the distinct disadvantage of their low boiling points. During the summer months when the engines operate hot, significant amounts of the alcohols are lost because of evaporation. These evaporative losses result in cosdy make-up requirements. Additionally, the alcohols have very low flash points and potentially flammable vapors. These safety concerns have, particularly in recent years, caused the use of alcohols to be completely discontinued for most heat-transfer systems. 

Commercial aviation utilizes low volatihty kerosene defined by a flash point minimum of 38 °C. The flammabiUty temperature has been invoked as a safety factor for handling fuels aboard aircraft carriers Navy JP-5 is a low volatihty kerosene of minimum flash point of 60 °C, similar to other Navy fuels. 

Ground turbine fuels are not subject to the constraints of an aircraft operating at reduced pressures of altitude. The temperature of fuel in ground tanks varies over a limited range, eg, 10—30°C, and the vapor pressure is defined by a safety-handling factor such as flash point temperature. Volatile fuels such as naphtha (No. 0-GT) are normally stored in a ground tank equipped with a vapor recovery system to minimise losses and meet local air quaUty codes on hydrocarbons. 

In view of the above adverse effects a safety factor should be applied where flammability is assessed using flash point. For pure liquids in containers the vapor should be considered potentially flammable if the liquid temperature is upward of at least 5°C below the reported flash point. For mixtures whose composition is less certain, such as petroleum mixtures, the safety factor should be about 15°C relative to the flash point [55]. Where combinations of adverse effects are identified the safety factors should be increased accordingly. A simple but very conservative approach is to assume that all liquids having a flash point <141°F may produce a flammable atmosphere under some ambient conditions, even where no mist or froth production is involved. A more practical approach is to assume that liquids handled in air at least 5-15°C below their closed cup flash points will not present ignition risks unless... 

Biodiesel does not present any special safety concerns. Pure biodiesel or biodiesel and petroleum diesel blends have a higher flash point than conventional diesel, making them safer to store and handle. Problems can occur with biodiesels in cold weather due to their high viscosity. Biodiesel has a higher degree of unsaturation in the fuel, which can make it vulnerable to oxidation during storage. 

The combustion characteristics of liquid fuels are similarly determined by measures of their ability to sustain a flame. Two measures of the combustion characteristics of liquid fuels especially related to safety are flash point and autoignition temperature. The flash point is the maximum temperature at which a liquid fuel can be maintained in an open vessel exposed to air before which it will sustain a flame... 

Safety tests. See also Flash point determination, 459 Salts, 32, 56... 

This long assessment of the analysis of the level of error of measurement that goes with flashpoint will be completed later (see para 1.3.7) by considering the effect of impurities that can be found in substances at their flashpoint. Nevertheless, it is sufficient to prove that it is not possible to have any confidence in the data of flash-points that can be found in the technical literature, especially when the safety expert has unique data only. To the author s knowledge, there were not until now... 

Alcohols such as methanol and ethanol are readily available and are occasionally used despite significant disadvantages, such as low boiling points. During summer months significant amounts of alcohol can be lost due to evaporation. Such losses lead to costly replacement of the additive. Furthermore, alcohols have low flash points, which may cause safety problems. Moreover, methanol is highly poisonous. Therefore, the use of alcohols has ceased almost completely in recent years. 

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